[syzbot] [hfs?] memory leak in hfsplus_init_fs

syzbot

unread,

Dec 5, 2025, 12:38:25 AM (2 days ago) Dec 5

to fran...@vivo.com, glau...@physik.fu-berlin.de, linux-...@vger.kernel.org, linux-...@vger.kernel.org, sl...@dubeyko.com, syzkall...@googlegroups.com

Hello,

syzbot found the following issue on:

HEAD commit: e69c7c175115 Merge tag 'timers_urgent_for_v6.18_rc8' of gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=116ffcb4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f30cc590c4f6da44
dashboard link: https://syzkaller.appspot.com/bug?extid=99f6ed51479b86ac4c41
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10eef912580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1534c192580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e1758d9b5b79/disk-e69c7c17.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/772ec0d0a545/vmlinux-e69c7c17.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d905337ef02b/bzImage-e69c7c17.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/65bc76439748/mount_4.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+99f6ed...@syzkaller.appspotmail.com

BUG: memory leak
unreferenced object 0xffff8881287f8a00 (size 512):
comm "syz.0.17", pid 6072, jiffies 4294944858
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc aaf4239b):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4983 [inline]
slab_alloc_node mm/slub.c:5288 [inline]
__kmalloc_cache_noprof+0x3a6/0x5b0 mm/slub.c:5766
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
hfsplus_init_fs_context+0x26/0x90 fs/hfsplus/super.c:678
alloc_fs_context+0x214/0x430 fs/fs_context.c:315
do_new_mount fs/namespace.c:3698 [inline]
path_mount+0x93c/0x12e0 fs/namespace.c:4028
do_mount fs/namespace.c:4041 [inline]
__do_sys_mount fs/namespace.c:4229 [inline]
__se_sys_mount fs/namespace.c:4206 [inline]
__x64_sys_mount+0x1a2/0x1e0 fs/namespace.c:4206
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff8881287f9a00 (size 512):
comm "syz.0.18", pid 6078, jiffies 4294944862
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc aaf4239b):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4983 [inline]
slab_alloc_node mm/slub.c:5288 [inline]
__kmalloc_cache_noprof+0x3a6/0x5b0 mm/slub.c:5766
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
hfsplus_init_fs_context+0x26/0x90 fs/hfsplus/super.c:678
alloc_fs_context+0x214/0x430 fs/fs_context.c:315
do_new_mount fs/namespace.c:3698 [inline]
path_mount+0x93c/0x12e0 fs/namespace.c:4028
do_mount fs/namespace.c:4041 [inline]
__do_sys_mount fs/namespace.c:4229 [inline]
__se_sys_mount fs/namespace.c:4206 [inline]
__x64_sys_mount+0x1a2/0x1e0 fs/namespace.c:4206
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff8881287f9c00 (size 512):
comm "syz.0.19", pid 6079, jiffies 4294944864
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc aaf4239b):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4983 [inline]
slab_alloc_node mm/slub.c:5288 [inline]
__kmalloc_cache_noprof+0x3a6/0x5b0 mm/slub.c:5766
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
hfsplus_init_fs_context+0x26/0x90 fs/hfsplus/super.c:678
alloc_fs_context+0x214/0x430 fs/fs_context.c:315
do_new_mount fs/namespace.c:3698 [inline]
path_mount+0x93c/0x12e0 fs/namespace.c:4028
do_mount fs/namespace.c:4041 [inline]
__do_sys_mount fs/namespace.c:4229 [inline]
__se_sys_mount fs/namespace.c:4206 [inline]
__x64_sys_mount+0x1a2/0x1e0 fs/namespace.c:4206
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF

---
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If you attach or paste a git patch, syzbot will apply it before testing.

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#syz undup

syzbot

unread,

Dec 5, 2025, 1:28:23 AM (2 days ago) Dec 5

to linux-...@vger.kernel.org, syzkall...@googlegroups.com

For archival purposes, forwarding an incoming command email to
linux-...@vger.kernel.org, syzkall...@googlegroups.com.

***

Subject: [PATCH] hfsplus: fix memory leak in hfsplus_fill_super() error path
Author: karti...@gmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

When hfsplus_fill_super() fails, the sbi structure is freed but
sb->s_fs_info is not set to NULL, leaving a dangling pointer.
This can lead to memory leak as reported by syzbot.

Set sb->s_fs_info to NULL after freeing sbi in the error path to
ensure proper cleanup.

Reported-by: syzbot+99f6ed...@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=99f6ed51479b86ac4c41
Signed-off-by: Deepanshu Kartikey <karti...@gmail.com>
---
fs/hfsplus/super.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 54e85e25a259..eb1b262be45e 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -630,6 +630,7 @@ static int hfsplus_fill_super(struct super_block *sb, struct fs_context *fc)
unload_nls(sbi->nls);
unload_nls(nls);
kfree(sbi);
+ sb->s_fs_info = NULL;
return err;
}

--
2.43.0

syzbot

unread,

Dec 5, 2025, 2:44:05 AM (2 days ago) Dec 5

to karti...@gmail.com, linux-...@vger.kernel.org, syzkall...@googlegroups.com

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

SYZFAIL: failed to recv rpc

SYZFAIL: failed to recv rpc

Warning: Permanently added '10.128.1.150' (ED25519) to the list of known hosts.
2025/12/05 07:43:31 parsed 1 programs
[ 44.042808][ T5812] cgroup: Unknown subsys name 'net'
[ 44.127074][ T5812] cgroup: Unknown subsys name 'cpuset'
[ 44.133650][ T5812] cgroup: Unknown subsys name 'rlimit'
Setting up swapspace version 1, size = 127995904 bytes
[ 52.645880][ T5812] Adding 124996k swap on ./swap-file. Priority:0 extents:1 across:124996k
[ 54.143312][ T5821] soft_limit_in_bytes is deprecated and will be removed. Please report your usecase to linu...@kvack.org if you depend on this functionality.
[ 54.299791][ T133] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 54.309905][ T133] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 54.320511][ T62] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 54.328915][ T62] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 54.497265][ T50] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[ 54.504519][ T50] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[ 54.511943][ T50] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[ 54.525287][ T50] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[ 54.532574][ T50] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[ 54.725582][ T5877] chnl_net:caif_netlink_parms(): no params data found
[ 54.747201][ T5877] bridge0: port 1(bridge_slave_0) entered blocking state
[ 54.754361][ T5877] bridge0: port 1(bridge_slave_0) entered disabled state
[ 54.762220][ T5877] bridge_slave_0: entered allmulticast mode
[ 54.768738][ T5877] bridge_slave_0: entered promiscuous mode
[ 54.775347][ T5877] bridge0: port 2(bridge_slave_1) entered blocking state
[ 54.782475][ T5877] bridge0: port 2(bridge_slave_1) entered disabled state
[ 54.789704][ T5877] bridge_slave_1: entered allmulticast mode
[ 54.796084][ T5877] bridge_slave_1: entered promiscuous mode
[ 54.818263][ T5877] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 54.828255][ T5877] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 54.841814][ T5877] team0: Port device team_slave_0 added
[ 54.848131][ T5877] team0: Port device team_slave_1 added
[ 54.859765][ T5877] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 54.867269][ T5877] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 54.895194][ T5877] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 54.906753][ T5877] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 54.913711][ T5877] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 54.940364][ T5877] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 54.959931][ T5877] hsr_slave_0: entered promiscuous mode
[ 54.966029][ T5877] hsr_slave_1: entered promiscuous mode
[ 55.003186][ T5877] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 55.011384][ T5877] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 55.019230][ T5877] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 55.027232][ T5877] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 55.039665][ T5877] bridge0: port 2(bridge_slave_1) entered blocking state
[ 55.046885][ T5877] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 55.054350][ T5877] bridge0: port 1(bridge_slave_0) entered blocking state
[ 55.061870][ T5877] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 55.080653][ T5877] 8021q: adding VLAN 0 to HW filter on device bond0
[ 55.090452][ T133] bridge0: port 1(bridge_slave_0) entered disabled state
[ 55.098390][ T133] bridge0: port 2(bridge_slave_1) entered disabled state
[ 55.108313][ T5877] 8021q: adding VLAN 0 to HW filter on device team0
[ 55.117493][ T133] bridge0: port 1(bridge_slave_0) entered blocking state
[ 55.124594][ T133] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 55.133971][ T12] bridge0: port 2(bridge_slave_1) entered blocking state
[ 55.141600][ T12] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 55.186705][ T5877] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 55.202568][ T5877] veth0_vlan: entered promiscuous mode
[ 55.209710][ T5877] veth1_vlan: entered promiscuous mode
[ 55.221357][ T5877] veth0_macvtap: entered promiscuous mode
[ 55.228585][ T5877] veth1_macvtap: entered promiscuous mode
[ 55.237919][ T5877] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 55.248299][ T5877] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 55.257538][ T58] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[ 55.266627][ T58] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[ 55.275497][ T58] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[ 55.284859][ T58] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[ 55.320966][ T62] netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 55.369319][ T62] netdevsim netdevsim0 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 55.447100][ T62] netdevsim netdevsim0 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 55.467896][ T62] netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
2025/12/05 07:43:45 executed programs: 0
[ 58.410697][ T62] bridge_slave_1: left allmulticast mode
[ 58.416833][ T62] bridge_slave_1: left promiscuous mode
[ 58.422540][ T62] bridge0: port 2(bridge_slave_1) entered disabled state
[ 58.431389][ T62] bridge_slave_0: left allmulticast mode
[ 58.437607][ T62] bridge_slave_0: left promiscuous mode
[ 58.443411][ T62] bridge0: port 1(bridge_slave_0) entered disabled state
[ 58.509109][ T62] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
[ 58.518647][ T62] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
[ 58.528253][ T62] bond0 (unregistering): Released all slaves
[ 58.608647][ T62] hsr_slave_0: left promiscuous mode
[ 58.614815][ T62] hsr_slave_1: left promiscuous mode
[ 58.621461][ T62] batman_adv: batadv0: Interface deactivated: batadv_slave_0
[ 58.629526][ T62] batman_adv: batadv0: Removing interface: batadv_slave_0
[ 58.637346][ T62] batman_adv: batadv0: Interface deactivated: batadv_slave_1
[ 58.644977][ T62] batman_adv: batadv0: Removing interface: batadv_slave_1
[ 58.653724][ T62] veth1_macvtap: left promiscuous mode
[ 58.659468][ T62] veth0_macvtap: left promiscuous mode
[ 58.665187][ T62] veth1_vlan: left promiscuous mode
[ 58.670728][ T62] veth0_vlan: left promiscuous mode
[ 58.701020][ T62] team0 (unregistering): Port device team_slave_1 removed
[ 58.709272][ T62] team0 (unregistering): Port device team_slave_0 removed
[ 61.343108][ T5134] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[ 61.350405][ T5134] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[ 61.357820][ T5134] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[ 61.365394][ T5134] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[ 61.373014][ T5134] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[ 61.410932][ T5987] chnl_net:caif_netlink_parms(): no params data found
[ 61.431401][ T5987] bridge0: port 1(bridge_slave_0) entered blocking state
[ 61.438773][ T5987] bridge0: port 1(bridge_slave_0) entered disabled state
[ 61.446357][ T5987] bridge_slave_0: entered allmulticast mode
[ 61.452606][ T5987] bridge_slave_0: entered promiscuous mode
[ 61.459577][ T5987] bridge0: port 2(bridge_slave_1) entered blocking state
[ 61.466850][ T5987] bridge0: port 2(bridge_slave_1) entered disabled state
[ 61.474214][ T5987] bridge_slave_1: entered allmulticast mode
[ 61.480620][ T5987] bridge_slave_1: entered promiscuous mode
[ 61.492762][ T5987] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 61.502926][ T5987] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 61.517255][ T5987] team0: Port device team_slave_0 added
[ 61.523465][ T5987] team0: Port device team_slave_1 added
[ 61.533816][ T5987] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 61.541096][ T5987] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 61.568438][ T5987] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 61.579932][ T5987] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 61.586999][ T5987] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 61.613994][ T5987] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 61.631616][ T5987] hsr_slave_0: entered promiscuous mode
[ 61.637415][ T5987] hsr_slave_1: entered promiscuous mode
[ 61.807060][ T5987] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 61.815018][ T5987] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 61.823175][ T5987] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 61.831557][ T5987] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 61.852955][ T5987] bridge0: port 2(bridge_slave_1) entered blocking state
[ 61.860270][ T5987] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 61.867863][ T5987] bridge0: port 1(bridge_slave_0) entered blocking state
[ 61.875026][ T5987] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 61.898612][ T5987] 8021q: adding VLAN 0 to HW filter on device bond0
[ 61.909150][ T12] bridge0: port 1(bridge_slave_0) entered disabled state
[ 61.917188][ T12] bridge0: port 2(bridge_slave_1) entered disabled state
[ 61.927534][ T5987] 8021q: adding VLAN 0 to HW filter on device team0
[ 61.938143][ T58] bridge0: port 1(bridge_slave_0) entered blocking state
[ 61.945307][ T58] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 61.958922][ T12] bridge0: port 2(bridge_slave_1) entered blocking state
[ 61.966035][ T12] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 61.982882][ T5987] hsr0: Slave A (hsr_slave_0) is not up; please bring it up to get a fully working HSR network
[ 61.994284][ T5987] hsr0: Slave B (hsr_slave_1) is not up; please bring it up to get a fully working HSR network
[ 62.053394][ T5987] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 62.072926][ T5987] veth0_vlan: entered promiscuous mode
[ 62.081131][ T5987] veth1_vlan: entered promiscuous mode
[ 62.095259][ T5987] veth0_macvtap: entered promiscuous mode
[ 62.103071][ T5987] veth1_macvtap: entered promiscuous mode
[ 62.114171][ T5987] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 62.124750][ T5987] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 62.135106][ T58] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[ 62.148659][ T58] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[ 62.160564][ T58] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[ 62.181317][ T58] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[ 62.191067][ T62] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
SYZFAIL: failed to recv rpc
[ 62.202944][ T62] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 62.215016][ T58] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 62.223739][ T58] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50

syzkaller build log:
go env (err=<nil>)
AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE='auto'
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/syzkaller/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/syzkaller/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build282997806=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOMODCACHE='/syzkaller/jobs/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs/linux/gopath'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/syzkaller/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.24.4'
GOWORK=''
PKG_CONFIG='pkg-config'

git status (err=<nil>)
HEAD detached at d6526ea3e6
nothing to commit, working tree clean

tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
go list -f '{{.Stale}}' -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d6526ea3e6ad9081c902859bbb80f9f840377cb4 -X github.com/google/syzkaller/prog.gitRevisionDate=20251126-113115" ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d6526ea3e6ad9081c902859bbb80f9f840377cb4 -X github.com/google/syzkaller/prog.gitRevisionDate=20251126-113115" ./sys/syz-sysgen
make .descriptions
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
bin/syz-sysgen
touch .descriptions
GOOS=linux GOARCH=amd64 go build -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d6526ea3e6ad9081c902859bbb80f9f840377cb4 -X github.com/google/syzkaller/prog.gitRevisionDate=20251126-113115" -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
mkdir -p ./bin/linux_amd64
g++ -o ./bin/linux_amd64/syz-executor executor/executor.cc \
-m64 -O2 -pthread -Wall -Werror -Wparentheses -Wunused-const-variable -Wframe-larger-than=16384 -Wno-stringop-overflow -Wno-array-bounds -Wno-format-overflow -Wno-unused-but-set-variable -Wno-unused-command-line-argument -static-pie -std=c++17 -I. -Iexecutor/_include -DGOOS_linux=1 -DGOARCH_amd64=1 \
-DHOSTGOOS_linux=1 -DGIT_REVISION=\"d6526ea3e6ad9081c902859bbb80f9f840377cb4\"
/usr/bin/ld: /tmp/ccoqPmtJ.o: in function `Connection::Connect(char const*, char const*)':
executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x104): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
./tools/check-syzos.sh 2>/dev/null

Tested on:

commit: 2061f18a Merge tag 'caps-pr-20251204' of git://git.ker..
git tree: upstream
kernel config: https://syzkaller.appspot.com/x/.config?x=4ec6d85125e91f07

dashboard link: https://syzkaller.appspot.com/bug?extid=99f6ed51479b86ac4c41
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=1497b01a580000

syzbot

unread,

Dec 5, 2025, 2:51:04 AM (2 days ago) Dec 5

to linux-...@vger.kernel.org, syzkall...@googlegroups.com

syzbot

unread,

Dec 5, 2025, 3:41:05 AM (2 days ago) Dec 5

to karti...@gmail.com, linux-...@vger.kernel.org, syzkall...@googlegroups.com

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

SYZFAIL: failed to recv rpc

SYZFAIL: failed to recv rpc

fd=3 want=4 recv=0 n=0 (errno 9: Bad file descriptor)

Warning: Permanently added '10.128.10.19' (ED25519) to the list of known hosts.
2025/12/05 08:40:16 parsed 1 programs
[ 41.176746][ T5819] cgroup: Unknown subsys name 'net'
[ 41.281133][ T5819] cgroup: Unknown subsys name 'cpuset'
[ 41.287826][ T5819] cgroup: Unknown subsys name 'rlimit'

Setting up swapspace version 1, size = 127995904 bytes

[ 49.291292][ T5819] Adding 124996k swap on ./swap-file. Priority:0 extents:1 across:124996k
[ 50.564658][ T5831] soft_limit_in_bytes is deprecated and will be removed. Please report your usecase to linu...@kvack.org if you depend on this functionality.
[ 50.685574][ T5838] chnl_net:caif_netlink_parms(): no params data found
[ 50.718744][ T5838] bridge0: port 1(bridge_slave_0) entered blocking state
[ 50.726547][ T5838] bridge0: port 1(bridge_slave_0) entered disabled state
[ 50.733855][ T5838] bridge_slave_0: entered allmulticast mode
[ 50.740422][ T5838] bridge_slave_0: entered promiscuous mode
[ 50.749111][ T5838] bridge0: port 2(bridge_slave_1) entered blocking state
[ 50.756705][ T5838] bridge0: port 2(bridge_slave_1) entered disabled state
[ 50.763860][ T5838] bridge_slave_1: entered allmulticast mode
[ 50.770087][ T5838] bridge_slave_1: entered promiscuous mode
[ 50.781997][ T5838] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 50.792353][ T5838] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 50.806088][ T5838] team0: Port device team_slave_0 added
[ 50.812289][ T5838] team0: Port device team_slave_1 added
[ 50.821770][ T5838] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 50.828751][ T5838] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 50.854896][ T5838] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 50.865811][ T5838] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 50.872758][ T5838] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 50.898803][ T5838] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 50.915511][ T5838] hsr_slave_0: entered promiscuous mode
[ 50.921517][ T5838] hsr_slave_1: entered promiscuous mode
[ 50.950832][ T5838] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 50.958488][ T5838] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 50.966517][ T5838] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 50.974219][ T5838] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 50.985730][ T5838] bridge0: port 2(bridge_slave_1) entered blocking state
[ 50.992793][ T5838] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 51.000070][ T5838] bridge0: port 1(bridge_slave_0) entered blocking state
[ 51.007177][ T5838] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 51.024053][ T5838] 8021q: adding VLAN 0 to HW filter on device bond0
[ 51.032907][ T2111] bridge0: port 1(bridge_slave_0) entered disabled state
[ 51.040759][ T2111] bridge0: port 2(bridge_slave_1) entered disabled state
[ 51.050315][ T5838] 8021q: adding VLAN 0 to HW filter on device team0
[ 51.059034][ T3542] bridge0: port 1(bridge_slave_0) entered blocking state
[ 51.066108][ T3542] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 51.075368][ T3868] bridge0: port 2(bridge_slave_1) entered blocking state
[ 51.082540][ T3868] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 51.123151][ T5838] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 51.138305][ T5838] veth0_vlan: entered promiscuous mode
[ 51.145381][ T5838] veth1_vlan: entered promiscuous mode
[ 51.156259][ T5838] veth0_macvtap: entered promiscuous mode
[ 51.163077][ T5838] veth1_macvtap: entered promiscuous mode
[ 51.172007][ T5838] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 51.181101][ T5838] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 51.189797][ T3529] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[ 51.198817][ T3529] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[ 51.208219][ T3529] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[ 51.217671][ T3529] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[ 51.268245][ T3529] netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 51.303208][ T3529] netdevsim netdevsim0 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 51.341444][ T3529] netdevsim netdevsim0 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 51.383323][ T3529] netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 51.595715][ T3542] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 51.604091][ T3542] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 51.614717][ T2111] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 51.622702][ T2111] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 51.649068][ T5908] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[ 51.656254][ T5908] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[ 51.664039][ T5908] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[ 51.671332][ T5908] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[ 51.678641][ T5908] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
2025/12/05 08:40:28 executed programs: 0
[ 54.510958][ T3529] bridge_slave_1: left allmulticast mode
[ 54.516655][ T3529] bridge_slave_1: left promiscuous mode
[ 54.522645][ T3529] bridge0: port 2(bridge_slave_1) entered disabled state
[ 54.530202][ T3529] bridge_slave_0: left allmulticast mode
[ 54.535912][ T3529] bridge_slave_0: left promiscuous mode
[ 54.541823][ T3529] bridge0: port 1(bridge_slave_0) entered disabled state
[ 54.582118][ T3529] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
[ 54.591202][ T3529] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
[ 54.600240][ T3529] bond0 (unregistering): Released all slaves
[ 54.661835][ T3529] hsr_slave_0: left promiscuous mode
[ 54.667972][ T3529] hsr_slave_1: left promiscuous mode
[ 54.673755][ T3529] batman_adv: batadv0: Interface deactivated: batadv_slave_0
[ 54.681245][ T3529] batman_adv: batadv0: Removing interface: batadv_slave_0
[ 54.688729][ T3529] batman_adv: batadv0: Interface deactivated: batadv_slave_1
[ 54.696292][ T3529] batman_adv: batadv0: Removing interface: batadv_slave_1
[ 54.704768][ T3529] veth1_macvtap: left promiscuous mode
[ 54.710447][ T3529] veth0_macvtap: left promiscuous mode
[ 54.715978][ T3529] veth1_vlan: left promiscuous mode
[ 54.721580][ T3529] veth0_vlan: left promiscuous mode
[ 54.744259][ T3529] team0 (unregistering): Port device team_slave_1 removed
[ 54.752630][ T3529] team0 (unregistering): Port device team_slave_0 removed
[ 57.411203][ T51] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[ 57.418346][ T51] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[ 57.425415][ T51] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[ 57.433086][ T51] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[ 57.440536][ T51] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[ 57.474037][ T5993] chnl_net:caif_netlink_parms(): no params data found
[ 57.492366][ T5993] bridge0: port 1(bridge_slave_0) entered blocking state
[ 57.499723][ T5993] bridge0: port 1(bridge_slave_0) entered disabled state
[ 57.507823][ T5993] bridge_slave_0: entered allmulticast mode
[ 57.514155][ T5993] bridge_slave_0: entered promiscuous mode
[ 57.520849][ T5993] bridge0: port 2(bridge_slave_1) entered blocking state
[ 57.527889][ T5993] bridge0: port 2(bridge_slave_1) entered disabled state
[ 57.535162][ T5993] bridge_slave_1: entered allmulticast mode
[ 57.541464][ T5993] bridge_slave_1: entered promiscuous mode
[ 57.552191][ T5993] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 57.562247][ T5993] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 57.576766][ T5993] team0: Port device team_slave_0 added
[ 57.583104][ T5993] team0: Port device team_slave_1 added
[ 57.592907][ T5993] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 57.599848][ T5993] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 57.626033][ T5993] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 57.637216][ T5993] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 57.644351][ T5993] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 57.670791][ T5993] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 57.687439][ T5993] hsr_slave_0: entered promiscuous mode
[ 57.693446][ T5993] hsr_slave_1: entered promiscuous mode
[ 57.886946][ T5993] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 57.895586][ T5993] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 57.903836][ T5993] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 57.912030][ T5993] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 57.931197][ T5993] bridge0: port 2(bridge_slave_1) entered blocking state
[ 57.938362][ T5993] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 57.945648][ T5993] bridge0: port 1(bridge_slave_0) entered blocking state
[ 57.952803][ T5993] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 57.973507][ T5993] 8021q: adding VLAN 0 to HW filter on device bond0
[ 57.982871][ T31] bridge0: port 1(bridge_slave_0) entered disabled state
[ 57.990406][ T31] bridge0: port 2(bridge_slave_1) entered disabled state
[ 58.000894][ T5993] 8021q: adding VLAN 0 to HW filter on device team0
[ 58.009845][ T31] bridge0: port 1(bridge_slave_0) entered blocking state
[ 58.016912][ T31] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 58.026584][ T31] bridge0: port 2(bridge_slave_1) entered blocking state
[ 58.033639][ T31] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 58.087594][ T5993] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 58.105504][ T5993] veth0_vlan: entered promiscuous mode
[ 58.113086][ T5993] veth1_vlan: entered promiscuous mode
[ 58.126723][ T5993] veth0_macvtap: entered promiscuous mode
[ 58.133631][ T5993] veth1_macvtap: entered promiscuous mode
[ 58.142945][ T5993] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 58.152148][ T5993] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 58.161440][ T3542] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[ 58.173806][ T3542] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[ 58.183259][ T3542] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[ 58.193398][ T3542] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[ 58.217473][ T31] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 58.228888][ T31] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50

SYZFAIL: failed to recv rpc

fd=3 want=4 recv=0 n=0 (errno 9: Bad file descriptor)
[ 58.240775][ T31] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 58.249148][ T31] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50

GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build2391967220=/tmp/go-build -gno-record-gcc-switches'

/usr/bin/ld: /tmp/ccdO0wGA.o: in function `Connection::Connect(char const*, char const*)':

executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x104): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
./tools/check-syzos.sh 2>/dev/null

Tested on:

commit: 2061f18a Merge tag 'caps-pr-20251204' of git://git.ker..
git tree: upstream
kernel config: https://syzkaller.appspot.com/x/.config?x=4ec6d85125e91f07
dashboard link: https://syzkaller.appspot.com/bug?extid=99f6ed51479b86ac4c41
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=1715bcc2580000

syzbot

unread,

Dec 5, 2025, 7:43:21 AM (2 days ago) Dec 5

to linux-...@vger.kernel.org, syzkall...@googlegroups.com

syzbot

unread,

Dec 5, 2025, 8:43:04 AM (2 days ago) Dec 5

to karti...@gmail.com, linux-...@vger.kernel.org, syzkall...@googlegroups.com

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
memory leak in hfsplus_init_fs_context

BUG: memory leak
unreferenced object 0xffff888128616800 (size 512):
comm "syz.0.17", pid 6730, jiffies 4294947750

hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

backtrace (crc 8418e967):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5258 [inline]
__kmalloc_cache_noprof+0x3a6/0x570 mm/slub.c:5766

kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]

hfsplus_init_fs_context+0x26/0x90 fs/hfsplus/super.c:700
alloc_fs_context+0x2a0/0x6e0 fs/fs_context.c:315
do_new_mount fs/namespace.c:3692 [inline]
path_mount+0x93f/0x1320 fs/namespace.c:4022
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount fs/namespace.c:4201 [inline]
__x64_sys_mount+0x1a2/0x1e0 fs/namespace.c:4201
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff888128617600 (size 512):
comm "syz.0.18", pid 6734, jiffies 4294947753

hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

backtrace (crc 8418e967):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5258 [inline]
__kmalloc_cache_noprof+0x3a6/0x570 mm/slub.c:5766

kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]

hfsplus_init_fs_context+0x26/0x90 fs/hfsplus/super.c:700
alloc_fs_context+0x2a0/0x6e0 fs/fs_context.c:315
do_new_mount fs/namespace.c:3692 [inline]
path_mount+0x93f/0x1320 fs/namespace.c:4022
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount fs/namespace.c:4201 [inline]
__x64_sys_mount+0x1a2/0x1e0 fs/namespace.c:4201
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff8881274f3800 (size 512):
comm "syz.0.19", pid 6739, jiffies 4294947757

hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

backtrace (crc 8418e967):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5258 [inline]
__kmalloc_cache_noprof+0x3a6/0x570 mm/slub.c:5766

kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]

hfsplus_init_fs_context+0x26/0x90 fs/hfsplus/super.c:700
alloc_fs_context+0x2a0/0x6e0 fs/fs_context.c:315
do_new_mount fs/namespace.c:3692 [inline]
path_mount+0x93f/0x1320 fs/namespace.c:4022
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount fs/namespace.c:4201 [inline]
__x64_sys_mount+0x1a2/0x1e0 fs/namespace.c:4201
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94

entry_SYSCALL_64_after_hwframe+0x77/0x7f

connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF

Tested on:

commit: 2061f18a Merge tag 'caps-pr-20251204' of git://git.ker..
git tree: upstream

console output: https://syzkaller.appspot.com/x/log.txt?x=15e6c41a580000

kernel config: https://syzkaller.appspot.com/x/.config?x=4ec6d85125e91f07
dashboard link: https://syzkaller.appspot.com/bug?extid=99f6ed51479b86ac4c41
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=10b2c41a580000

syzbot

unread,

Dec 5, 2025, 9:48:54 AM (2 days ago) Dec 5

to linux-...@vger.kernel.org, syzkall...@googlegroups.com

For archival purposes, forwarding an incoming command email to
linux-...@vger.kernel.org, syzkall...@googlegroups.com.

***

Subject: [PATCH] hfsplus: fix memory leak in hfsplus_fill_super() error path
Author: karti...@gmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

When hfsplus_fill_super() fails, the sbi structure is freed but neither
sb->s_fs_info nor fc->s_fs_info are set to NULL. Since sget_fc() copies
fc->s_fs_info to sb->s_fs_info without clearing fc->s_fs_info, both
pointers reference the same memory. After fill_super frees sbi,
hfsplus_free_fc() may operate on a dangling pointer, causing memory
leak or other issues.

Set both sb->s_fs_info and fc->s_fs_info to NULL after freeing sbi

in the error path to ensure proper cleanup.

Reported-by: syzbot+99f6ed...@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=99f6ed51479b86ac4c41
Signed-off-by: Deepanshu Kartikey <karti...@gmail.com>
---

fs/hfsplus/super.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 54e85e25a259..f242b88f6633 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -630,6 +630,8 @@ static int hfsplus_fill_super(struct super_block *sb, struct fs_context *fc)

unload_nls(sbi->nls);
unload_nls(nls);
kfree(sbi);
+ sb->s_fs_info = NULL;

+ fc->s_fs_info = NULL;
return err;
}

--
2.43.0

syzbot

unread,

Dec 5, 2025, 10:04:04 AM (2 days ago) Dec 5

to karti...@gmail.com, linux-...@vger.kernel.org, syzkall...@googlegroups.com

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
memory leak in hfsplus_init_fs_context

BUG: memory leak

unreferenced object 0xffff888112296400 (size 512):
comm "syz.0.17", pid 6722, jiffies 4294946670

hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc 8418e967):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5258 [inline]
__kmalloc_cache_noprof+0x3a6/0x570 mm/slub.c:5766
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]

hfsplus_init_fs_context+0x26/0x90 fs/hfsplus/super.c:701

alloc_fs_context+0x2a0/0x6e0 fs/fs_context.c:315
do_new_mount fs/namespace.c:3692 [inline]
path_mount+0x93f/0x1320 fs/namespace.c:4022
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount fs/namespace.c:4201 [inline]
__x64_sys_mount+0x1a2/0x1e0 fs/namespace.c:4201
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak

unreferenced object 0xffff888109a34400 (size 512):
comm "syz.0.18", pid 6729, jiffies 4294946674

hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc 8418e967):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5258 [inline]
__kmalloc_cache_noprof+0x3a6/0x570 mm/slub.c:5766
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]

hfsplus_init_fs_context+0x26/0x90 fs/hfsplus/super.c:701

alloc_fs_context+0x2a0/0x6e0 fs/fs_context.c:315
do_new_mount fs/namespace.c:3692 [inline]
path_mount+0x93f/0x1320 fs/namespace.c:4022
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount fs/namespace.c:4201 [inline]
__x64_sys_mount+0x1a2/0x1e0 fs/namespace.c:4201
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak

unreferenced object 0xffff888109a34a00 (size 512):
comm "syz.0.19", pid 6732, jiffies 4294946677

hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc 8418e967):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5258 [inline]
__kmalloc_cache_noprof+0x3a6/0x570 mm/slub.c:5766
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]

hfsplus_init_fs_context+0x26/0x90 fs/hfsplus/super.c:701

alloc_fs_context+0x2a0/0x6e0 fs/fs_context.c:315
do_new_mount fs/namespace.c:3692 [inline]
path_mount+0x93f/0x1320 fs/namespace.c:4022
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount fs/namespace.c:4201 [inline]
__x64_sys_mount+0x1a2/0x1e0 fs/namespace.c:4201
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF

Tested on:

commit: 2061f18a Merge tag 'caps-pr-20251204' of git://git.ker..
git tree: upstream

console output: https://syzkaller.appspot.com/x/log.txt?x=16b1c41a580000

kernel config: https://syzkaller.appspot.com/x/.config?x=4ec6d85125e91f07
dashboard link: https://syzkaller.appspot.com/bug?extid=99f6ed51479b86ac4c41
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=10e25ab4580000

syzbot

unread,

Dec 5, 2025, 2:06:05 PM (2 days ago) Dec 5

to david.hun...@gmail.com, fran...@vivo.com, glau...@physik.fu-berlin.de, linux-...@vger.kernel.org, linux-...@vger.kernel.org, sk...@linuxfoundation.org, sl...@dubeyko.com, swarajga...@gmail.com, syzkall...@googlegroups.com

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

SYZFAIL: failed to recv rpc

SYZFAIL: failed to recv rpc
fd=3 want=4 recv=0 n=0 (errno 9: Bad file descriptor)

Warning: Permanently added '10.128.0.245' (ED25519) to the list of known hosts.
2025/12/05 19:05:15 parsed 1 programs
[ 55.119214][ T5818] cgroup: Unknown subsys name 'net'
[ 55.259974][ T5818] cgroup: Unknown subsys name 'cpuset'
[ 55.266582][ T5818] cgroup: Unknown subsys name 'rlimit'

Setting up swapspace version 1, size = 127995904 bytes

[ 63.696572][ T5818] Adding 124996k swap on ./swap-file. Priority:0 extents:1 across:124996k
[ 65.016628][ T5828] soft_limit_in_bytes is deprecated and will be removed. Please report your usecase to linu...@kvack.org if you depend on this functionality.
[ 65.422993][ T5880] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[ 65.430458][ T5880] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[ 65.437558][ T5880] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[ 65.445167][ T5880] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[ 65.452744][ T5880] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[ 65.561974][ T5890] chnl_net:caif_netlink_parms(): no params data found
[ 65.584453][ T5890] bridge0: port 1(bridge_slave_0) entered blocking state
[ 65.591882][ T5890] bridge0: port 1(bridge_slave_0) entered disabled state
[ 65.599824][ T5890] bridge_slave_0: entered allmulticast mode
[ 65.606225][ T5890] bridge_slave_0: entered promiscuous mode
[ 65.612881][ T5890] bridge0: port 2(bridge_slave_1) entered blocking state
[ 65.619978][ T5890] bridge0: port 2(bridge_slave_1) entered disabled state
[ 65.627492][ T5890] bridge_slave_1: entered allmulticast mode
[ 65.634027][ T5890] bridge_slave_1: entered promiscuous mode
[ 65.645743][ T5890] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 65.655760][ T5890] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 65.669914][ T5890] team0: Port device team_slave_0 added
[ 65.676301][ T5890] team0: Port device team_slave_1 added
[ 65.686571][ T5890] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 65.693917][ T5890] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 65.720230][ T5890] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 65.731988][ T5890] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 65.739356][ T5890] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 65.766444][ T5890] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 65.787487][ T5890] hsr_slave_0: entered promiscuous mode
[ 65.793267][ T5890] hsr_slave_1: entered promiscuous mode
[ 65.822570][ T5890] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 65.830459][ T5890] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 65.838351][ T5890] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 65.846563][ T5890] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 65.860377][ T5890] bridge0: port 2(bridge_slave_1) entered blocking state
[ 65.867973][ T5890] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 65.875564][ T5890] bridge0: port 1(bridge_slave_0) entered blocking state
[ 65.882626][ T5890] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 65.899327][ T5890] 8021q: adding VLAN 0 to HW filter on device bond0
[ 65.908810][ T65] bridge0: port 1(bridge_slave_0) entered disabled state
[ 65.916368][ T65] bridge0: port 2(bridge_slave_1) entered disabled state
[ 65.926332][ T5890] 8021q: adding VLAN 0 to HW filter on device team0
[ 65.935247][ T55] bridge0: port 1(bridge_slave_0) entered blocking state
[ 65.942415][ T55] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 65.952498][ T55] bridge0: port 2(bridge_slave_1) entered blocking state
[ 65.959571][ T55] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 66.001572][ T5890] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 66.016258][ T5890] veth0_vlan: entered promiscuous mode
[ 66.023938][ T5890] veth1_vlan: entered promiscuous mode
[ 66.035919][ T5890] veth0_macvtap: entered promiscuous mode
[ 66.043178][ T5890] veth1_macvtap: entered promiscuous mode
[ 66.052173][ T5890] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 66.061801][ T5890] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 66.071356][ T55] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[ 66.081780][ T55] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[ 66.091070][ T55] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[ 66.100260][ T55] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[ 66.142913][ T55] netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 66.164181][ T31] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 66.172643][ T31] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 66.182052][ T55] netdevsim netdevsim0 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 66.195368][ T31] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 66.203729][ T31] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 66.230379][ T55] netdevsim netdevsim0 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 66.280211][ T55] netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
2025/12/05 19:05:28 executed programs: 0
[ 69.506006][ T55] bridge_slave_1: left allmulticast mode
[ 69.511800][ T55] bridge_slave_1: left promiscuous mode
[ 69.517491][ T55] bridge0: port 2(bridge_slave_1) entered disabled state
[ 69.525504][ T55] bridge_slave_0: left allmulticast mode
[ 69.531369][ T55] bridge_slave_0: left promiscuous mode
[ 69.537068][ T55] bridge0: port 1(bridge_slave_0) entered disabled state
[ 69.601288][ T55] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
[ 69.611079][ T55] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
[ 69.620253][ T55] bond0 (unregistering): Released all slaves
[ 69.670943][ T55] hsr_slave_0: left promiscuous mode
[ 69.676955][ T55] hsr_slave_1: left promiscuous mode
[ 69.682958][ T55] batman_adv: batadv0: Interface deactivated: batadv_slave_0
[ 69.691003][ T55] batman_adv: batadv0: Removing interface: batadv_slave_0
[ 69.698476][ T55] batman_adv: batadv0: Interface deactivated: batadv_slave_1
[ 69.706532][ T55] batman_adv: batadv0: Removing interface: batadv_slave_1
[ 69.715577][ T55] veth1_macvtap: left promiscuous mode
[ 69.721203][ T55] veth0_macvtap: left promiscuous mode
[ 69.726728][ T55] veth1_vlan: left promiscuous mode
[ 69.732096][ T55] veth0_vlan: left promiscuous mode
[ 69.757386][ T55] team0 (unregistering): Port device team_slave_1 removed
[ 69.766234][ T55] team0 (unregistering): Port device team_slave_0 removed
[ 70.169404][ T1309] ieee802154 phy0 wpan0: encryption failed: -22
[ 70.175683][ T1309] ieee802154 phy1 wpan1: encryption failed: -22
[ 72.047051][ T5134] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[ 72.054869][ T5134] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[ 72.062046][ T5134] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[ 72.070042][ T5134] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[ 72.077520][ T5134] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[ 72.113196][ T5989] chnl_net:caif_netlink_parms(): no params data found
[ 72.132758][ T5989] bridge0: port 1(bridge_slave_0) entered blocking state
[ 72.140022][ T5989] bridge0: port 1(bridge_slave_0) entered disabled state
[ 72.147223][ T5989] bridge_slave_0: entered allmulticast mode
[ 72.153712][ T5989] bridge_slave_0: entered promiscuous mode
[ 72.160489][ T5989] bridge0: port 2(bridge_slave_1) entered blocking state
[ 72.167745][ T5989] bridge0: port 2(bridge_slave_1) entered disabled state
[ 72.174993][ T5989] bridge_slave_1: entered allmulticast mode
[ 72.181245][ T5989] bridge_slave_1: entered promiscuous mode
[ 72.192621][ T5989] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 72.202629][ T5989] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 72.217391][ T5989] team0: Port device team_slave_0 added
[ 72.224120][ T5989] team0: Port device team_slave_1 added
[ 72.234181][ T5989] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 72.241867][ T5989] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 72.268532][ T5989] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 72.280051][ T5989] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 72.287416][ T5989] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 72.314180][ T5989] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 72.331466][ T5989] hsr_slave_0: entered promiscuous mode
[ 72.337615][ T5989] hsr_slave_1: entered promiscuous mode
[ 72.513584][ T5989] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 72.521437][ T5989] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 72.529452][ T5989] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 72.537435][ T5989] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 72.551368][ T5989] bridge0: port 2(bridge_slave_1) entered blocking state
[ 72.558478][ T5989] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 72.565936][ T5989] bridge0: port 1(bridge_slave_0) entered blocking state
[ 72.573710][ T5989] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 72.596776][ T5989] 8021q: adding VLAN 0 to HW filter on device bond0
[ 72.606884][ T31] bridge0: port 1(bridge_slave_0) entered disabled state
[ 72.615077][ T31] bridge0: port 2(bridge_slave_1) entered disabled state
[ 72.625976][ T5989] 8021q: adding VLAN 0 to HW filter on device team0
[ 72.634865][ T31] bridge0: port 1(bridge_slave_0) entered blocking state
[ 72.642139][ T31] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 72.660348][ T31] bridge0: port 2(bridge_slave_1) entered blocking state
[ 72.667635][ T31] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 72.717525][ T5989] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 72.736386][ T5989] veth0_vlan: entered promiscuous mode
[ 72.743922][ T5989] veth1_vlan: entered promiscuous mode
[ 72.757219][ T5989] veth0_macvtap: entered promiscuous mode
[ 72.764388][ T5989] veth1_macvtap: entered promiscuous mode
[ 72.774941][ T5989] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 72.784711][ T5989] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 72.794630][ T35] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[ 72.807307][ T35] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[ 72.816371][ T723] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[ 72.828572][ T723] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[ 72.847366][ T35] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 72.856762][ T35] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50

SYZFAIL: failed to recv rpc
fd=3 want=4 recv=0 n=0 (errno 9: Bad file descriptor)

[ 72.870318][ T723] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 72.878614][ T723] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50

GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build1479309889=/tmp/go-build -gno-record-gcc-switches'

GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''

GOMOD='/syzkaller/jobs-2/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOMODCACHE='/syzkaller/jobs-2/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs-2/linux/gopath'

GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/syzkaller/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.24.4'
GOWORK=''
PKG_CONFIG='pkg-config'

git status (err=<nil>)
HEAD detached at d6526ea3e

nothing to commit, working tree clean

tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
go list -f '{{.Stale}}' -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d6526ea3e6ad9081c902859bbb80f9f840377cb4 -X github.com/google/syzkaller/prog.gitRevisionDate=20251126-113115" ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d6526ea3e6ad9081c902859bbb80f9f840377cb4 -X github.com/google/syzkaller/prog.gitRevisionDate=20251126-113115" ./sys/syz-sysgen
make .descriptions
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
bin/syz-sysgen
touch .descriptions
GOOS=linux GOARCH=amd64 go build -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d6526ea3e6ad9081c902859bbb80f9f840377cb4 -X github.com/google/syzkaller/prog.gitRevisionDate=20251126-113115" -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
mkdir -p ./bin/linux_amd64
g++ -o ./bin/linux_amd64/syz-executor executor/executor.cc \
-m64 -O2 -pthread -Wall -Werror -Wparentheses -Wunused-const-variable -Wframe-larger-than=16384 -Wno-stringop-overflow -Wno-array-bounds -Wno-format-overflow -Wno-unused-but-set-variable -Wno-unused-command-line-argument -static-pie -std=c++17 -I. -Iexecutor/_include -DGOOS_linux=1 -DGOARCH_amd64=1 \
-DHOSTGOOS_linux=1 -DGIT_REVISION=\"d6526ea3e6ad9081c902859bbb80f9f840377cb4\"

/usr/bin/ld: /tmp/ccXWETje.o: in function `Connection::Connect(char const*, char const*)':

executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x104): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
./tools/check-syzos.sh 2>/dev/null

Tested on:

commit: e69c7c17 Merge tag 'timers_urgent_for_v6.18_rc8' of gi..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel config: https://syzkaller.appspot.com/x/.config?x=f30cc590c4f6da44

dashboard link: https://syzkaller.appspot.com/bug?extid=99f6ed51479b86ac4c41
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=14477cc2580000

Viacheslav Dubeyko

unread,

Dec 5, 2025, 3:02:45 PM (2 days ago) Dec 5

to Swaraj Gaikwad, syzbot+99f6ed...@syzkaller.appspotmail.com, fran...@vivo.com, glau...@physik.fu-berlin.de, linux-...@vger.kernel.org, linux-...@vger.kernel.org, sk...@linuxfoundation.org, david.hun...@gmail.com, syzkall...@googlegroups.com

On Sat, 2025-12-06 at 00:09 +0000, Swaraj Gaikwad wrote:
> syzbot reported a memory leak in the hfsplus mount path when the
> mount
> fails, which occurs because the fs_context API moves ownership of
> fc->s_fs_info to sb->s_fs_info early in sget_fc().
>
> When filesystems are mounted using the new API, the VFS (specifically
> sget_fc) transfers the ownership of the context's s_fs_info (the
> 'sbi'
> struct) to the superblock (sb->s_fs_info) and clears the context
> pointer.
>
> If the mount fails after this transfer the VFS calls
> deactivate_locked_super, which invokes the filesystem's kill_sb
> callback. Previously, hfsplus used the generic kill_block_super,
> which
> does not free sb->s_fs_info, resulting in the 'sbi' structure and its
> loaded NLS tables being leaked.
>
> Fix this by implementing a filesystem-specific ->kill_sb() that frees
> sb->s_fs_info and its NLS resources before calling
> kill_block_super().
> Also remove the early kfree(sbi) from hfsplus_fill_super()’s error
> path,
> because the superblock unconditionally owns s_fs_info when using the
> fs_context API.
>
> Testing:
> This fix was verified by building the kernel with the .config
> provided
> by the syzkaller reporter and running the reproducer. The reproducer
> now runs successfully without triggering any memory leaks or kernel
> errors.
>
> #syz test:
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> e69c7c175115
>
> Reported-by: syzbot+99f6ed...@syzkaller.appspotmail.com
> Signed-off-by: Swaraj Gaikwad <swarajga...@gmail.com>
> ---
> fs/hfsplus/super.c | 16 ++++++++++++++--
> 1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
> index 16bc4abc67e0..fa7420d08da1 100644
> --- a/fs/hfsplus/super.c
> +++ b/fs/hfsplus/super.c
> @@ -629,7 +629,6 @@ static int hfsplus_fill_super(struct super_block
> *sb, struct fs_context *fc)
> out_unload_nls:
> unload_nls(sbi->nls);
> unload_nls(nls);
> - kfree(sbi);
> return err;
> }
>
> @@ -688,10 +687,23 @@ static int hfsplus_init_fs_context(struct
> fs_context *fc)
> return 0;
> }
>
> +static void hfsplus_kill_sb(struct super_block *sb)
> +{
> +    struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
> +
> +    if (sbi) {
> +        unload_nls(sbi->nls);
> +        kfree(sbi);

> + sb->s_fs_info = NULL;
> + }

> +
> + kill_block_super(sb);
> +}
> +
> static struct file_system_type hfsplus_fs_type = {
> .owner = THIS_MODULE,
> .name = "hfsplus",
> - .kill_sb = kill_block_super,
> + .kill_sb = hfsplus_kill_sb,
> .fs_flags = FS_REQUIRES_DEV,
> .init_fs_context = hfsplus_init_fs_context,
> };
>
> base-commit: 6bda50f4333fa61c07f04f790fdd4e2c9f4ca610
> --
> 2.52.0

Sorry, but this patch [1] already fixes the issue.

Thanks,
Slava.

[1]
https://lore.kernel.org/linux-fsdevel/20251201222843.82310-...@gmail.com/

syzbot ci

unread,

Dec 6, 2025, 4:25:11 AM (22 hours ago) Dec 6

to david.hun...@gmail.com, fran...@vivo.com, glau...@physik.fu-berlin.de, linux-...@vger.kernel.org, linux-...@vger.kernel.org, sk...@linuxfoundation.org, sl...@dubeyko.com, swarajga...@gmail.com, syz...@syzkaller.appspotmail.com, syzkall...@googlegroups.com, syz...@lists.linux.dev, syzkall...@googlegroups.com

syzbot ci has tested the following series

[v1] hfsplus: fix memory leak on mount failure
https://lore.kernel.org/all/20251206000902.71178...@gmail.com
* [PATCH v1] hfsplus: fix memory leak on mount failure

and found the following issues:
* SYZFAIL: failed to recv rpc
* WARNING: ODEBUG bug in hfsplus_kill_sb
* general protection fault in __timer_delete
* general protection fault in hfsplus_sync_fs

Full report is available here:
https://ci.syzbot.org/series/ea775ab1-67a5-4497-b4d6-8c7b2b7d90aa

***

SYZFAIL: failed to recv rpc

tree: torvalds
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
base: 2061f18ad76ecaddf8ed17df81b8611ea88dbddd
arch: amd64
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
config: https://ci.syzbot.org/builds/591f3943-d010-4b2d-a026-67cc75802376/config
C repro: https://ci.syzbot.org/findings/53a2b5e3-41ae-4650-9300-ec3fdd87f47a/c_repro
syz repro: https://ci.syzbot.org/findings/53a2b5e3-41ae-4650-9300-ec3fdd87f47a/syz_repro

SYZFAIL: failed to recv rpc

***

WARNING: ODEBUG bug in hfsplus_kill_sb

tree: torvalds
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
base: 2061f18ad76ecaddf8ed17df81b8611ea88dbddd
arch: amd64
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
config: https://ci.syzbot.org/builds/591f3943-d010-4b2d-a026-67cc75802376/config
C repro: https://ci.syzbot.org/findings/3c918e05-49e7-4855-bee1-5aafc9a5b5a4/c_repro
syz repro: https://ci.syzbot.org/findings/3c918e05-49e7-4855-bee1-5aafc9a5b5a4/syz_repro

------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff88810a17ea38 object type: timer_list hint: delayed_sync_fs+0x0/0xf0 fs/hfsplus/super.c:-1
WARNING: lib/debugobjects.c:615 at 0x0, CPU#1: syz-executor/5946
Modules linked in:
CPU: 1 UID: 0 PID: 5946 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:debug_print_object lib/debugobjects.c:612 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1099 [inline]
RIP: 0010:debug_check_no_obj_freed+0x44a/0x550 lib/debugobjects.c:1129
Code: 89 44 24 20 e8 47 4a 92 fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 20 02 c0 8b 48 c7 c2 40 07 c0 8b 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
RSP: 0018:ffffc900032b7c18 EFLAGS: 00010246
RAX: ffffffff829ca540 RBX: ffffffff99a849a0 RCX: 0000000000000000
RDX: ffffffff8bc00740 RSI: ffffffff8bc00220 RDI: ffffffff8f8b7a70
RBP: ffffffff8b6d2540 R08: ffff88810a17ea38 R09: ffffffff8b6d36a0
R10: dffffc0000000000 R11: ffffffff81ae6210 R12: ffff88810a17ec00
R13: ffffffff8f8b7a70 R14: ffff88810a17e000 R15: ffff88810a17ea38
FS: 0000555587657500(0000) GS:ffff8882a9e8e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b55b316738 CR3: 0000000175d56000 CR4: 00000000000006f0
Call Trace:
<TASK>
slab_free_hook mm/slub.c:2471 [inline]
slab_free mm/slub.c:6663 [inline]
kfree+0x13b/0x660 mm/slub.c:6871
hfsplus_kill_sb+0x72/0xb0 fs/hfsplus/super.c:717
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
task_work_run+0x1d4/0x260 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f540cf90af7
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffc80b82ab8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f540cfee72f RCX: 00007f540cf90af7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc80b82b70
RBP: 00007ffc80b82b70 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc80b83c00
R13: 00007f540cfee72f R14: 000000000001120e R15: 00007ffc80b83c40
</TASK>
----------------
Code disassembly (best guess):
0: 89 44 24 20 mov %eax,0x20(%rsp)
4: e8 47 4a 92 fd call 0xfd924a50
9: 48 8b 44 24 20 mov 0x20(%rsp),%rax
e: 4c 8b 4d 00 mov 0x0(%rbp),%r9
12: 4c 89 ef mov %r13,%rdi
15: 48 c7 c6 20 02 c0 8b mov $0xffffffff8bc00220,%rsi
1c: 48 c7 c2 40 07 c0 8b mov $0xffffffff8bc00740,%rdx
23: 8b 0c 24 mov (%rsp),%ecx
26: 4d 89 f8 mov %r15,%r8
29: 50 push %rax
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: 48 83 c4 08 add $0x8,%rsp
33: 4c 8b 6c 24 18 mov 0x18(%rsp),%r13
38: 48 rex.W
39: b9 00 00 00 00 mov $0x0,%ecx
3e: 00 fc add %bh,%ah

***

general protection fault in __timer_delete

tree: torvalds
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
base: 2061f18ad76ecaddf8ed17df81b8611ea88dbddd
arch: amd64
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
config: https://ci.syzbot.org/builds/591f3943-d010-4b2d-a026-67cc75802376/config
syz repro: https://ci.syzbot.org/findings/58118c78-00cf-40ba-b5b2-a878d7311794/syz_repro

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000048: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000240-0x0000000000000247]
CPU: 1 UID: 0 PID: 5944 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:timer_is_static_object+0x26/0x80 kernel/time/timer.c:691
Code: 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 48 89 fb 49 bf 00 00 00 00 00 fc ff df e8 95 e8 12 00 4c 8d 73 08 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 8b e0 78 00 49 83 3e 00 74 09 e8
RSP: 0018:ffffc900044279a8 EFLAGS: 00010006
RAX: 0000000000000048 RBX: 0000000000000238 RCX: ffff88817417d7c0
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000238
RBP: ffffffff99a2bcc0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff81ae62d0 R12: ffffffff8b6d2550
R13: fffffffffffffffe R14: 0000000000000240 R15: dffffc0000000000
FS: 000055555c51f500(0000) GS:ffff8882a9e8e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd2077ec08 CR3: 00000001138de000 CR4: 00000000000006f0
Call Trace:
<TASK>
lookup_object_or_alloc lib/debugobjects.c:679 [inline]
debug_object_assert_init+0x16f/0x380 lib/debugobjects.c:1008
debug_timer_assert_init kernel/time/timer.c:803 [inline]
debug_assert_init kernel/time/timer.c:848 [inline]
__timer_delete+0x31/0x390 kernel/time/timer.c:1366
try_to_grab_pending kernel/workqueue.c:2061 [inline]
work_grab_pending+0x121/0x990 kernel/workqueue.c:2154
__cancel_work+0x85/0x2c0 kernel/workqueue.c:4368
__cancel_work_sync+0x1f/0x110 kernel/workqueue.c:4385
hfsplus_put_super+0x56/0x3e0 fs/hfsplus/super.c:328
generic_shutdown_super+0x135/0x2c0 fs/super.c:643
kill_block_super+0x44/0x90 fs/super.c:1730
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
task_work_run+0x1d4/0x260 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3b71f90af7
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffd2077f3b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f3b71fee72f RCX: 00007f3b71f90af7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd2077f470
RBP: 00007ffd2077f470 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd20780500
R13: 00007f3b71fee72f R14: 000000000000f9eb R15: 00007ffd20780540
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:timer_is_static_object+0x26/0x80 kernel/time/timer.c:691
Code: 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 48 89 fb 49 bf 00 00 00 00 00 fc ff df e8 95 e8 12 00 4c 8d 73 08 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 8b e0 78 00 49 83 3e 00 74 09 e8
RSP: 0018:ffffc900044279a8 EFLAGS: 00010006
RAX: 0000000000000048 RBX: 0000000000000238 RCX: ffff88817417d7c0
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000238
RBP: ffffffff99a2bcc0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff81ae62d0 R12: ffffffff8b6d2550
R13: fffffffffffffffe R14: 0000000000000240 R15: dffffc0000000000
FS: 000055555c51f500(0000) GS:ffff8882a9e8e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd2077ec08 CR3: 00000001138de000 CR4: 00000000000006f0
----------------
Code disassembly (best guess):
0: 90 nop
1: 90 nop
2: 90 nop
3: 90 nop
4: f3 0f 1e fa endbr64
8: 41 57 push %r15
a: 41 56 push %r14
c: 53 push %rbx
d: 48 89 fb mov %rdi,%rbx
10: 49 bf 00 00 00 00 00 movabs $0xdffffc0000000000,%r15
17: fc ff df
1a: e8 95 e8 12 00 call 0x12e8b4
1f: 4c 8d 73 08 lea 0x8(%rbx),%r14
23: 4c 89 f0 mov %r14,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 f7 mov %r14,%rdi
34: e8 8b e0 78 00 call 0x78e0c4
39: 49 83 3e 00 cmpq $0x0,(%r14)
3d: 74 09 je 0x48
3f: e8 .byte 0xe8

***

general protection fault in hfsplus_sync_fs

tree: torvalds
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
base: 2061f18ad76ecaddf8ed17df81b8611ea88dbddd
arch: amd64
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
config: https://ci.syzbot.org/builds/591f3943-d010-4b2d-a026-67cc75802376/config
C repro: https://ci.syzbot.org/findings/990368ba-5843-438f-bf7c-132c134aa1f3/c_repro
syz repro: https://ci.syzbot.org/findings/990368ba-5843-438f-bf7c-132c134aa1f3/syz_repro

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 0 UID: 0 PID: 5946 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:hfsplus_sync_fs+0x70/0x3d0 fs/hfsplus/super.c:255
Code: 31 ff 89 ee e8 31 a9 24 ff 85 ed 0f 84 71 01 00 00 4c 89 24 24 0f 1f 44 00 00 e8 db a4 24 ff 4d 8d 7e 28 4c 89 f8 48 c1 e8 03 <80> 3c 18 00 74 08 4c 89 ff e8 d2 9c 8a ff 4d 8b 3f 49 83 c7 08 4c
RSP: 0018:ffffc900036e7a48 EFLAGS: 00010206
RAX: 0000000000000005 RBX: dffffc0000000000 RCX: ffff88810bbc57c0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffc900036e78a7 R09: 1ffff920006dcf14
R10: dffffc0000000000 R11: ffffffff829ca640 R12: ffff88811624e000
R13: ffff88811624e158 R14: 0000000000000000 R15: 0000000000000028
FS: 0000555564915500(0000) GS:ffff88818ea8e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00003e720 CR3: 0000000011796000 CR4: 00000000000006f0
Call Trace:
<TASK>
sync_filesystem+0x1cf/0x230 fs/sync.c:66
generic_shutdown_super+0x6f/0x2c0 fs/super.c:622
kill_block_super+0x44/0x90 fs/super.c:1730
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
task_work_run+0x1d4/0x260 kernel/task_work.c:233
get_signal+0x11ec/0x1340 kernel/signal.c:2807
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdd6ef90af7
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffd2aacb428 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fdd6efee72f RCX: 00007fdd6ef90af7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd2aacb4e0
RBP: 00007ffd2aacb4e0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd2aacc570
R13: 00007fdd6efee72f R14: 000000000000febb R15: 00007ffd2aacc5b0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:hfsplus_sync_fs+0x70/0x3d0 fs/hfsplus/super.c:255
Code: 31 ff 89 ee e8 31 a9 24 ff 85 ed 0f 84 71 01 00 00 4c 89 24 24 0f 1f 44 00 00 e8 db a4 24 ff 4d 8d 7e 28 4c 89 f8 48 c1 e8 03 <80> 3c 18 00 74 08 4c 89 ff e8 d2 9c 8a ff 4d 8b 3f 49 83 c7 08 4c
RSP: 0018:ffffc900036e7a48 EFLAGS: 00010206
RAX: 0000000000000005 RBX: dffffc0000000000 RCX: ffff88810bbc57c0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffc900036e78a7 R09: 1ffff920006dcf14
R10: dffffc0000000000 R11: ffffffff829ca640 R12: ffff88811624e000
R13: ffff88811624e158 R14: 0000000000000000 R15: 0000000000000028
FS: 0000555564915500(0000) GS:ffff8882a9e8e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ccfe37e9e0 CR3: 0000000011796000 CR4: 00000000000006f0
----------------
Code disassembly (best guess):
0: 31 ff xor %edi,%edi
2: 89 ee mov %ebp,%esi
4: e8 31 a9 24 ff call 0xff24a93a
9: 85 ed test %ebp,%ebp
b: 0f 84 71 01 00 00 je 0x182
11: 4c 89 24 24 mov %r12,(%rsp)
15: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
1a: e8 db a4 24 ff call 0xff24a4fa
1f: 4d 8d 7e 28 lea 0x28(%r14),%r15
23: 4c 89 f8 mov %r15,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) <-- trapping instruction
2e: 74 08 je 0x38
30: 4c 89 ff mov %r15,%rdi
33: e8 d2 9c 8a ff call 0xff8a9d0a
38: 4d 8b 3f mov (%r15),%r15
3b: 49 83 c7 08 add $0x8,%r15
3f: 4c rex.WR

***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syz...@syzkaller.appspotmail.com

---
This report is generated by a bot. It may contain errors.

syzbot ci engineers can be reached at syzk...@googlegroups.com.

Swaraj Gaikwad

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Dec 6, 2025, 4:29:59 AM (22 hours ago) Dec 6

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[syzbot] [hfs?] memory leak in hfsplus_init_fs_context

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Swaraj Gaikwad