[syzbot] [bluetooth?] KASAN: slab-use-after-free Read in mgmt_pending_remove

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4001bda0cc91 Merge branch 'selftests-vsock-refactor-and-im..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17f2897c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=4dda49799a90cd0f
dashboard link: https://syzkaller.appspot.com/bug?extid=9aa47cd4633a3cf92a80
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11a21c12580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f1a9e5dda198/disk-4001bda0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e0d7f0aa5468/vmlinux-4001bda0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9cef7d2ebe50/bzImage-4001bda0.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9aa47c...@syzkaller.appspotmail.com

RAX: ffffffffffffffda RBX: 00007f5543fe5fa0 RCX: 00007f5543d8f6c9
RDX: 0000000000000007 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f5544b69090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f5543fe6038 R14: 00007f5543fe5fa0 R15: 00007ffe72e0a568
</TASK>
Bluetooth: hci0: no memory for command
==================================================================
BUG: KASAN: slab-use-after-free in mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316
Read of size 8 at addr ffff888077164818 by task syz.0.17/5989

CPU: 0 UID: 0 PID: 5989 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xca/0x240 mm/kasan/report.c:482
kasan_report+0x118/0x150 mm/kasan/report.c:595
mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316
set_link_security+0x5c2/0x710 net/bluetooth/mgmt.c:1918
hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
sock_write_iter+0x279/0x360 net/socket.c:1195
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5543d8f6c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5544b69038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5543fe5fa0 RCX: 00007f5543d8f6c9
RDX: 0000000000000007 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f5544b69090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f5543fe6038 R14: 00007f5543fe5fa0 R15: 00007ffe72e0a568
</TASK>

Allocated by task 5989:
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417
kasan_kmalloc include/linux/kasan.h:262 [inline]
__kmalloc_cache_noprof+0x3d5/0x6f0 mm/slub.c:5763
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
mgmt_pending_new+0x65/0x1e0 net/bluetooth/mgmt_util.c:269
mgmt_pending_add+0x35/0x140 net/bluetooth/mgmt_util.c:296
set_link_security+0x557/0x710 net/bluetooth/mgmt.c:1910
hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
sock_write_iter+0x279/0x360 net/socket.c:1195
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5991:
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
__kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587
kasan_save_free_info mm/kasan/kasan.h:406 [inline]
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2539 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x19a/0x6d0 mm/slub.c:6837
mgmt_pending_free net/bluetooth/mgmt_util.c:311 [inline]
mgmt_pending_foreach+0x30d/0x380 net/bluetooth/mgmt_util.c:257
mgmt_index_removed+0x112/0x2f0 net/bluetooth/mgmt.c:9477
hci_sock_bind+0xbe9/0x1000 net/bluetooth/hci_sock.c:1314
__sys_bind_socket net/socket.c:1874 [inline]
__sys_bind+0x2c6/0x3e0 net/socket.c:1905
__do_sys_bind net/socket.c:1910 [inline]
__se_sys_bind net/socket.c:1908 [inline]
__x64_sys_bind+0x7a/0x90 net/socket.c:1908
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888077164800
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 24 bytes inside of
freed 96-byte region [ffff888077164800, ffff888077164860)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x77164
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801a026280 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1098, tgid 1098 (kworker/u8:6), ts 87994876358, free_ts 87976357652
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850
prep_new_page mm/page_alloc.c:1858 [inline]
get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3884
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
alloc_slab_page mm/slub.c:3055 [inline]
allocate_slab+0x96/0x350 mm/slub.c:3228
new_slab mm/slub.c:3282 [inline]
___slab_alloc+0xe94/0x18a0 mm/slub.c:4651
__slab_alloc+0x65/0x100 mm/slub.c:4770
__slab_alloc_node mm/slub.c:4846 [inline]
slab_alloc_node mm/slub.c:5268 [inline]
__kmalloc_cache_noprof+0x411/0x6f0 mm/slub.c:5758
kmalloc_noprof include/linux/slab.h:957 [inline]
dst_cow_metrics_generic+0x56/0x1c0 net/core/dst.c:193
dst_metrics_write_ptr include/net/dst.h:136 [inline]
dst_metric_set include/net/dst.h:197 [inline]
icmp6_dst_alloc+0x264/0x420 net/ipv6/route.c:3335
ndisc_send_skb+0x3f1/0x1510 net/ipv6/ndisc.c:491
ndisc_send_ns+0xcb/0x150 net/ipv6/ndisc.c:670
addrconf_dad_work+0xaae/0x14b0 net/ipv6/addrconf.c:4282
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
page last free pid 1113 tgid 1113 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1394 [inline]
__free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906
__slab_free+0x2e7/0x390 mm/slub.c:5962
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4970 [inline]
slab_alloc_node mm/slub.c:5280 [inline]
kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5332
__alloc_skb+0x112/0x2d0 net/core/skbuff.c:664
alloc_skb include/linux/skbuff.h:1383 [inline]
nlmsg_new include/net/netlink.h:1055 [inline]
nl80211_send_ibss_bssid+0x8d/0x430 net/wireless/nl80211.c:19952
__cfg80211_ibss_joined+0x34a/0x440 net/wireless/ibss.c:50
cfg80211_process_wdev_events+0x38a/0x4f0 net/wireless/util.c:1143
cfg80211_process_rdev_events+0xa1/0x110 net/wireless/util.c:1170
cfg80211_event_work+0x31/0x70 net/wireless/core.c:334
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158

Memory state around the buggy address:
ffff888077164700: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
ffff888077164780: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
>ffff888077164800: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff888077164880: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
ffff888077164900: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[Edward Adam Davis]

#syz test

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 262bf984d2aa..33e725798c34 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -9474,7 +9474,9 @@ void mgmt_index_removed(struct hci_dev *hdev)
if (hci_test_quirk(hdev, HCI_QUIRK_RAW_DEVICE))
return;

+ hci_dev_lock(hdev);
mgmt_pending_foreach(0, hdev, true, cmd_complete_rsp, &match);
+ hci_dev_unlock(hdev);

if (hci_dev_test_flag(hdev, HCI_UNCONFIGURED)) {
mgmt_index_event(MGMT_EV_UNCONF_INDEX_REMOVED, hdev, NULL, 0,

[syzbot]

Hello,

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

022][ T5851] ? kmem_cache_free+0x19b/0x690
[ 98.045044][ T5851] do_exit+0x6b5/0x2300
[ 98.045064][ T5851] ? do_raw_spin_lock+0x121/0x290
[ 98.045083][ T5851] ? __pfx_do_exit+0x10/0x10
[ 98.045105][ T5851] do_group_exit+0x21c/0x2d0
[ 98.045124][ T5851] ? lockdep_hardirqs_on+0x9c/0x150
[ 98.045138][ T5851] get_signal+0x1285/0x1340
[ 98.045158][ T5851] arch_do_signal_or_restart+0xa0/0x790
[ 98.045181][ T5851] ? __pfx_arch_do_signal_or_restart+0x10/0x10
[ 98.045206][ T5851] ? exit_to_user_mode_loop+0x40/0x130
[ 98.045220][ T5851] exit_to_user_mode_loop+0x72/0x130
[ 98.045233][ T5851] do_syscall_64+0x2bd/0xfa0
[ 98.045247][ T5851] ? lockdep_hardirqs_on+0x9c/0x150
[ 98.045260][ T5851] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 98.045274][ T5851] ? clear_bhb_loop+0x60/0xb0
[ 98.045289][ T5851] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 98.045302][ T5851] RIP: 0033:0x7f01e85915e7
[ 98.045315][ T5851] Code: Unable to access opcode bytes at 0x7f01e85915bd.
[ 98.045322][ T5851] RSP: 002b:00007ffd3b28dfa8 EFLAGS: 00000202 ORIG_RAX: 0000000000000029
[ 98.045339][ T5851] RAX: 0000000000000003 RBX: 00007f01e87b1300 RCX: 00007f01e85915e7
[ 98.045350][ T5851] RDX: 0000000000000006 RSI: 0000000000000001 RDI: 0000000000000002
[ 98.045358][ T5851] RBP: 00007ffd3b28e6cc R08: 0000000000000000 R09: 00007ffd3b28e3d7
[ 98.045367][ T5851] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000001
[ 98.045375][ T5851] R13: 00007f01e87b1280 R14: 0000000000000000 R15: 00007ffd3b28e720
[ 98.045390][ T5851] </TASK>
[ 98.378540][ T12] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 98.386690][ T12] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 98.389814][ T5858] ieee80211 phy4: Selected rate control algorithm 'minstrel_ht'
[ 98.411678][ T79] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 98.419746][ T79] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 99.353370][ T5894] chnl_net:caif_netlink_parms(): no params data found
[ 99.418057][ T5894] bridge0: port 1(bridge_slave_0) entered blocking state
[ 99.425428][ T5894] bridge0: port 1(bridge_slave_0) entered disabled state
[ 99.432627][ T5894] bridge_slave_0: entered allmulticast mode
[ 99.439520][ T5894] bridge_slave_0: entered promiscuous mode
[ 99.447024][ T5894] bridge0: port 2(bridge_slave_1) entered blocking state
[ 99.454503][ T5894] bridge0: port 2(bridge_slave_1) entered disabled state
[ 99.462695][ T5894] bridge_slave_1: entered allmulticast mode
[ 99.470917][ T5894] bridge_slave_1: entered promiscuous mode
[ 99.501077][ T5894] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 99.512217][ T5894] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 99.532942][ T5894] team0: Port device team_slave_0 added
[ 99.540510][ T5894] team0: Port device team_slave_1 added
[ 99.561110][ T5894] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 99.568213][ T5894] 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.
[ 99.594552][ T5894] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 99.606103][ T5894] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 99.613063][ T5894] 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.
[ 99.639753][ T5894] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 99.674242][ T5894] hsr_slave_0: entered promiscuous mode
[ 99.680522][ T5894] hsr_slave_1: entered promiscuous mode
[ 99.748239][ T5894] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 99.757893][ T5894] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 99.767651][ T5894] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 99.776497][ T5894] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 99.794605][ T5894] bridge0: port 2(bridge_slave_1) entered blocking state
[ 99.801694][ T5894] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 99.809289][ T5894] bridge0: port 1(bridge_slave_0) entered blocking state
[ 99.816402][ T5894] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 99.849208][ T5894] 8021q: adding VLAN 0 to HW filter on device bond0
[ 99.861911][ T79] bridge0: port 1(bridge_slave_0) entered disabled state
[ 99.870963][ T79] bridge0: port 2(bridge_slave_1) entered disabled state
[ 99.882660][ T5894] 8021q: adding VLAN 0 to HW filter on device team0
[ 99.895117][ T50] bridge0: port 1(bridge_slave_0) entered blocking state
[ 99.902499][ T50] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 99.914797][ T79] bridge0: port 2(bridge_slave_1) entered blocking state
[ 99.921907][ T79] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 100.027173][ T5894] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 100.059727][ T5894] veth0_vlan: entered promiscuous mode
[ 100.069248][ T5894] veth1_vlan: entered promiscuous mode
[ 100.089179][ T5894] veth0_macvtap: entered promiscuous mode
[ 100.098172][ T5894] veth1_macvtap: entered promiscuous mode
[ 100.110792][ T5894] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 100.123421][ T5894] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 100.135149][ T50] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[ 100.144394][ T50] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[ 100.154732][ T50] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[ 100.163861][ T50] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[ 100.247849][ T79] netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 100.282107][ T79] netdevsim netdevsim0 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 100.345609][ T79] netdevsim netdevsim0 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 100.431459][ T79] netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
2025/11/16 08:20:35 executed programs: 0
[ 100.990449][ T5146] Bluetooth: hci1: unexpected cc 0x0c03 length: 249 > 1
[ 100.998317][ T5146] Bluetooth: hci1: unexpected cc 0x1003 length: 249 > 9
[ 101.007725][ T5146] Bluetooth: hci1: unexpected cc 0x1001 length: 249 > 9
[ 101.015889][ T5146] Bluetooth: hci1: unexpected cc 0x0c23 length: 249 > 4
[ 101.024741][ T5146] Bluetooth: hci1: unexpected cc 0x0c38 length: 249 > 2
[ 101.118697][ T5934] chnl_net:caif_netlink_parms(): no params data found
[ 101.161430][ T5934] bridge0: port 1(bridge_slave_0) entered blocking state
[ 101.169408][ T5934] bridge0: port 1(bridge_slave_0) entered disabled state
[ 101.176899][ T5934] bridge_slave_0: entered allmulticast mode
[ 101.183902][ T5934] bridge_slave_0: entered promiscuous mode
[ 101.191277][ T5934] bridge0: port 2(bridge_slave_1) entered blocking state
[ 101.198558][ T5934] bridge0: port 2(bridge_slave_1) entered disabled state
[ 101.205858][ T5934] bridge_slave_1: entered allmulticast mode
[ 101.212895][ T5934] bridge_slave_1: entered promiscuous mode
[ 101.235387][ T5934] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 101.247326][ T5934] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 101.273904][ T5934] team0: Port device team_slave_0 added
[ 101.280932][ T5934] team0: Port device team_slave_1 added
[ 101.298158][ T5934] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 101.305607][ T5934] 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.
[ 101.332185][ T5934] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 101.344400][ T5934] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 101.351729][ T5934] 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.
[ 101.379297][ T5934] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 101.409545][ T5934] hsr_slave_0: entered promiscuous mode
[ 101.416136][ T5934] hsr_slave_1: entered promiscuous mode
[ 101.422075][ T5934] debugfs: 'hsr0' already exists in 'hsr'
[ 101.428232][ T5934] Cannot create hsr debugfs directory
[ 103.083403][ T5852] Bluetooth: hci1: command tx timeout
[ 103.408906][ T79] bridge_slave_1: left allmulticast mode
[ 103.416318][ T79] bridge_slave_1: left promiscuous mode
[ 103.422340][ T79] bridge0: port 2(bridge_slave_1) entered disabled state
[ 103.434700][ T79] bridge_slave_0: left allmulticast mode
[ 103.440485][ T79] bridge_slave_0: left promiscuous mode
[ 103.446862][ T79] bridge0: port 1(bridge_slave_0) entered disabled state
[ 103.557628][ T79] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
[ 103.568674][ T79] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
[ 103.578654][ T79] bond0 (unregistering): Released all slaves
[ 103.688535][ T79] hsr_slave_0: left promiscuous mode
[ 103.699423][ T79] hsr_slave_1: left promiscuous mode
[ 103.705766][ T79] batman_adv: batadv0: Interface deactivated: batadv_slave_0
[ 103.714781][ T79] batman_adv: batadv0: Removing interface: batadv_slave_0
[ 103.722702][ T79] batman_adv: batadv0: Interface deactivated: batadv_slave_1
[ 103.730697][ T79] batman_adv: batadv0: Removing interface: batadv_slave_1
[ 103.742099][ T79] veth1_macvtap: left promiscuous mode
[ 103.748282][ T79] veth0_macvtap: left promiscuous mode
[ 103.753965][ T79] veth1_vlan: left promiscuous mode
[ 103.759445][ T79] veth0_vlan: left promiscuous mode
[ 103.921563][ T79] team0 (unregistering): Port device team_slave_1 removed
[ 103.932559][ T79] team0 (unregistering): Port device team_slave_0 removed
[ 104.214906][ T5934] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 104.228969][ T5934] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 104.239124][ T5934] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 104.249179][ T5934] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 104.341776][ T5934] 8021q: adding VLAN 0 to HW filter on device bond0
[ 104.358525][ T5934] 8021q: adding VLAN 0 to HW filter on device team0
[ 104.375257][ T1085] bridge0: port 1(bridge_slave_0) entered blocking state
[ 104.382582][ T1085] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 104.401872][ T1085] bridge0: port 2(bridge_slave_1) entered blocking state
[ 104.409195][ T1085] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 104.738722][ T5934] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 104.765852][ T5934] veth0_vlan: entered promiscuous mode
[ 104.775508][ T5934] veth1_vlan: entered promiscuous mode
[ 104.796938][ T5934] veth0_macvtap: entered promiscuous mode
[ 104.805872][ T5934] veth1_macvtap: entered promiscuous mode
[ 104.818189][ T5934] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 104.830594][ T5934] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 104.844301][ T1144] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[ 104.854320][ T12] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[ 104.866000][ T12] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[ 104.874997][ T12] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[ 104.897274][ T5934] ieee80211 phy5: Selected rate control algorithm 'minstrel_ht'
[ 104.916565][ T1085] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 104.917918][ T5934] ieee80211 phy6: Selected rate control algorithm 'minstrel_ht'
[ 104.928653][ T1085] 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)
[ 104.951336][ T1085] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 104.959711][ T1085] 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-build2571666063=/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 07e030dea
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=07e030dea6e6d9ca88b75bb3be2810f47083b328 -X github.com/google/syzkaller/prog.gitRevisionDate=20251112-115923" ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=07e030dea6e6d9ca88b75bb3be2810f47083b328 -X github.com/google/syzkaller/prog.gitRevisionDate=20251112-115923" ./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=07e030dea6e6d9ca88b75bb3be2810f47083b328 -X github.com/google/syzkaller/prog.gitRevisionDate=20251112-115923" -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=\"07e030dea6e6d9ca88b75bb3be2810f47083b328\"
/usr/bin/ld: /tmp/ccL2C3R3.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


Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=13ac6658580000


Tested on:

commit: c9dfb92d Merge branch 'mlx5-next' of git://git.kernel...
git tree: net-next

kernel config: https://syzkaller.appspot.com/x/.config?x=4dda49799a90cd0f
dashboard link: https://syzkaller.appspot.com/bug?extid=9aa47cd4633a3cf92a80
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

patch: https://syzkaller.appspot.com/x/patch.diff?x=14445212580000

[Edward Adam Davis]

#syz test

diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index fc866759910d..ad19022ae127 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -1311,7 +1311,9 @@ static int hci_sock_bind(struct socket *sock, struct sockaddr *addr,
goto done;
}

+ hci_dev_lock(hdev);
mgmt_index_removed(hdev);
+ hci_dev_unlock(hdev);

err = hci_dev_open(hdev->id);
if (err) {

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+9aa47c...@syzkaller.appspotmail.com
Tested-by: syzbot+9aa47c...@syzkaller.appspotmail.com

Tested on:

commit: c9dfb92d Merge branch 'mlx5-next' of git://git.kernel...
git tree: net-next

console output: https://syzkaller.appspot.com/x/log.txt?x=1629a212580000

kernel config: https://syzkaller.appspot.com/x/.config?x=4dda49799a90cd0f
dashboard link: https://syzkaller.appspot.com/bug?extid=9aa47cd4633a3cf92a80
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

patch: https://syzkaller.appspot.com/x/patch.diff?x=1234dd32580000

Note: testing is done by a robot and is best-effort only.

[Edward Adam Davis]

There is a potential race condition between sock bind and socket write
iter. bind may free the same cmd via mgmt_pending before write iter sends
the cmd, just as syzbot reported in UAF[1].

Here we use hci_dev_lock to synchronize the two, thereby avoiding the
UAF mentioned in [1].

[1]
syzbot reported:

BUG: KASAN: slab-use-after-free in mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316
Read of size 8 at addr ffff888077164818 by task syz.0.17/5989

Call Trace:

mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316
set_link_security+0x5c2/0x710 net/bluetooth/mgmt.c:1918
hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
sock_write_iter+0x279/0x360 net/socket.c:1195

Allocated by task 5989:

mgmt_pending_add+0x35/0x140 net/bluetooth/mgmt_util.c:296
set_link_security+0x557/0x710 net/bluetooth/mgmt.c:1910
hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
sock_write_iter+0x279/0x360 net/socket.c:1195

Freed by task 5991:

mgmt_pending_free net/bluetooth/mgmt_util.c:311 [inline]
mgmt_pending_foreach+0x30d/0x380 net/bluetooth/mgmt_util.c:257
mgmt_index_removed+0x112/0x2f0 net/bluetooth/mgmt.c:9477
hci_sock_bind+0xbe9/0x1000 net/bluetooth/hci_sock.c:1314

Fixes: 6fe26f694c82 ("Bluetooth: MGMT: Protect mgmt_pending list with its own lock")
Reported-by: syzbot+9aa47c...@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9aa47cd4633a3cf92a80
Tested-by: syzbot+9aa47c...@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <ead...@qq.com>
---
net/bluetooth/hci_sock.c | 2 ++
1 file changed, 2 insertions(+)

--
2.43.0