[syzbot] [f2fs?] KASAN: slab-use-after-free Read in destroy_device_list

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 23a80d462c67 Merge tag 'rcu.release.v6.8' of https://githu..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=140d9913e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=7c8840a4a09eab8
dashboard link: https://syzkaller.appspot.com/bug?extid=a5e651ca75fa0260acd5
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10071683e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15f2e4dde80000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-23a80d46.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/786a4e8b6bd9/vmlinux-23a80d46.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8778a236d47f/bzImage-23a80d46.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/24774803a66f/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a5e651...@syzkaller.appspotmail.com

F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock
F2FS-fs (loop0): Unrecognized mount option "noacl fastboot" or missing value
==================================================================
BUG: KASAN: slab-use-after-free in destroy_device_list+0x195/0x200 fs/f2fs/super.c:1606
Read of size 4 at addr ffff88802356d77c by task syz-executor178/5154

CPU: 3 PID: 5154 Comm: syz-executor178 Not tainted 6.7.0-syzkaller-09918-g23a80d462c67 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:377 [inline]
print_report+0xc4/0x620 mm/kasan/report.c:488
kasan_report+0xda/0x110 mm/kasan/report.c:601
destroy_device_list+0x195/0x200 fs/f2fs/super.c:1606
kill_f2fs_super+0x2c6/0x430 fs/f2fs/super.c:4932
deactivate_locked_super+0xbc/0x1a0 fs/super.c:477
mount_bdev+0x277/0x2d0 fs/super.c:1665
legacy_get_tree+0x109/0x220 fs/fs_context.c:662
vfs_get_tree+0x8c/0x370 fs/super.c:1784
do_new_mount fs/namespace.c:3352 [inline]
path_mount+0x14e6/0x1f20 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount fs/namespace.c:3875 [inline]
__x64_sys_mount+0x293/0x310 fs/namespace.c:3875
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f30633d797a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe0148d918 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffe0148d930 RCX: 00007f30633d797a
RDX: 0000000020000040 RSI: 0000000020000080 RDI: 00007ffe0148d930
RBP: 0000000000000004 R08: 00007ffe0148d970 R09: 002c65686361635f
R10: 0000000000000000 R11: 0000000000000286 R12: 0000000000000000
R13: 00007ffe0148d970 R14: 0000000000000003 R15: 00000000013bd7ef
</TASK>

Allocated by task 5154:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:372 [inline]
__kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:389
kmalloc include/linux/slab.h:590 [inline]
kzalloc include/linux/slab.h:711 [inline]
f2fs_fill_super+0xfe/0x8e50 fs/f2fs/super.c:4397
mount_bdev+0x1df/0x2d0 fs/super.c:1663
legacy_get_tree+0x109/0x220 fs/fs_context.c:662
vfs_get_tree+0x8c/0x370 fs/super.c:1784
do_new_mount fs/namespace.c:3352 [inline]
path_mount+0x14e6/0x1f20 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount fs/namespace.c:3875 [inline]
__x64_sys_mount+0x293/0x310 fs/namespace.c:3875
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

Freed by task 5154:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:634
poison_slab_object mm/kasan/common.c:241 [inline]
__kasan_slab_free+0x121/0x1b0 mm/kasan/common.c:257
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2121 [inline]
slab_free mm/slub.c:4299 [inline]
kfree+0x124/0x360 mm/slub.c:4409
f2fs_fill_super+0x270c/0x8e50 fs/f2fs/super.c:4882
mount_bdev+0x1df/0x2d0 fs/super.c:1663
legacy_get_tree+0x109/0x220 fs/fs_context.c:662
vfs_get_tree+0x8c/0x370 fs/super.c:1784
do_new_mount fs/namespace.c:3352 [inline]
path_mount+0x14e6/0x1f20 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount fs/namespace.c:3875 [inline]
__x64_sys_mount+0x293/0x310 fs/namespace.c:3875
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

The buggy address belongs to the object at ffff88802356c000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 6012 bytes inside of
freed 8192-byte region [ffff88802356c000, ffff88802356e000)

The buggy address belongs to the physical page:
page:ffffea00008d5a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23568
head:ffffea00008d5a00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
ksm flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888013043180 ffffea0000954e00 dead000000000003
raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4877, tgid 4877 (dhcpcd), ts 26455000649, free_ts 26430514243
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1533
prep_new_page mm/page_alloc.c:1540 [inline]
get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3311
__alloc_pages+0x22f/0x2440 mm/page_alloc.c:4567
__alloc_pages_node include/linux/gfp.h:238 [inline]
alloc_pages_node include/linux/gfp.h:261 [inline]
alloc_slab_page mm/slub.c:2190 [inline]
allocate_slab mm/slub.c:2354 [inline]
new_slab+0xcc/0x3a0 mm/slub.c:2407
___slab_alloc+0x4af/0x19a0 mm/slub.c:3540
__slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3625
__slab_alloc_node mm/slub.c:3678 [inline]
slab_alloc_node mm/slub.c:3850 [inline]
__do_kmalloc_node mm/slub.c:3980 [inline]
__kmalloc_node_track_caller+0x35b/0x460 mm/slub.c:4001
kmalloc_reserve+0xef/0x260 net/core/skbuff.c:582
__alloc_skb+0x12b/0x330 net/core/skbuff.c:651
alloc_skb include/linux/skbuff.h:1296 [inline]
netlink_dump+0x2e5/0xca0 net/netlink/af_netlink.c:2231
netlink_recvmsg+0x9ff/0xf20 net/netlink/af_netlink.c:1990
sock_recvmsg_nosec net/socket.c:1046 [inline]
sock_recvmsg+0xe2/0x170 net/socket.c:1068
____sys_recvmsg+0x21f/0x5c0 net/socket.c:2803
___sys_recvmsg+0x115/0x1a0 net/socket.c:2845
__sys_recvmsg+0x114/0x1e0 net/socket.c:2875
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83
page last free pid 4877 tgid 4877 stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1140 [inline]
free_unref_page_prepare+0x51f/0xb10 mm/page_alloc.c:2346
free_unref_page+0x33/0x3c0 mm/page_alloc.c:2486
__put_partials+0x14c/0x160 mm/slub.c:2922
qlink_free mm/kasan/quarantine.c:160 [inline]
qlist_free_all+0x58/0x150 mm/kasan/quarantine.c:176
kasan_quarantine_reduce+0x18e/0x1d0 mm/kasan/quarantine.c:283
__kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:324
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3813 [inline]
slab_alloc_node mm/slub.c:3860 [inline]
kmem_cache_alloc+0x136/0x320 mm/slub.c:3867
kmem_cache_zalloc include/linux/slab.h:701 [inline]
__kernfs_new_node+0xd3/0x890 fs/kernfs/dir.c:615
kernfs_new_node+0x94/0x110 fs/kernfs/dir.c:679
__kernfs_create_file+0x53/0x340 fs/kernfs/file.c:1025
sysfs_add_file_mode_ns+0x1ff/0x3b0 fs/sysfs/file.c:307
create_files fs/sysfs/group.c:64 [inline]
internal_create_group+0x31c/0xb50 fs/sysfs/group.c:152
internal_create_groups+0x9d/0x150 fs/sysfs/group.c:192
device_add_groups drivers/base/core.c:2727 [inline]
device_add_attrs drivers/base/core.c:2847 [inline]
device_add+0xf66/0x1aa0 drivers/base/core.c:3579
netdev_register_kobject+0x187/0x3e0 net/core/net-sysfs.c:2055
register_netdevice+0x1385/0x1da0 net/core/dev.c:10261

Memory state around the buggy address:
ffff88802356d600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88802356d680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802356d700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88802356d780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88802356d800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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[Edward Adam Davis]

please test slab-use-after-free Read in destroy_device_list

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 23a80d462c67

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index d00d21a8b53a..9939e2445b1e 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -4879,6 +4879,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
free_sbi:
if (sbi->s_chksum_driver)
crypto_free_shash(sbi->s_chksum_driver);
+ sb->s_fs_info = NULL;
kfree(sbi);

/* give only one another chance */

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+a5e651...@syzkaller.appspotmail.com

Tested on:

commit: 23a80d46 Merge tag 'rcu.release.v6.8' of https://githu..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=16dfa2dbe80000
kernel config: https://syzkaller.appspot.com/x/.config?x=36f64072074e3eab

dashboard link: https://syzkaller.appspot.com/bug?extid=a5e651ca75fa0260acd5
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=13271683e80000

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

[Edward Adam Davis]

When the call to f2fs_fill_super() fails, only the memory occupied by sbi is
released, but s_fs_info is not set to NULL, this will cause the current issue
to occur.

Reported-and-tested-by: syzbot+a5e651...@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <ead...@qq.com>
---
fs/f2fs/super.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index d00d21a8b53a..9939e2445b1e 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -4879,6 +4879,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
free_sbi:
if (sbi->s_chksum_driver)
crypto_free_shash(sbi->s_chksum_driver);
+ sb->s_fs_info = NULL;
kfree(sbi);

/* give only one another chance */

--
2.43.0

[syzbot]

syzbot has bisected this issue to:

commit 275dca4630c165edea9abe27113766bc1173f878
Author: Eric Biggers <ebig...@google.com>
Date: Wed Dec 27 17:14:28 2023 +0000

f2fs: move release of block devices to after kill_block_super()

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10639913e80000
start commit: 052d534373b7 Merge tag 'exfat-for-6.8-rc1' of git://git.ke..
git tree: upstream
final oops: https://syzkaller.appspot.com/x/report.txt?x=12639913e80000
console output: https://syzkaller.appspot.com/x/log.txt?x=14639913e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=878a2a4af11180a7
dashboard link: https://syzkaller.appspot.com/bug?extid=a5e651ca75fa0260acd5
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=167b0f47e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11255313e80000

Reported-by: syzbot+a5e651...@syzkaller.appspotmail.com
Fixes: 275dca4630c1 ("f2fs: move release of block devices to after kill_block_super()")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[Eric Biggers]

#syz fix: f2fs: fix double free of f2fs_sb_info