[moderation] [block?] KASAN: slab-use-after-free Read in bdev_release

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 052d534373b7 Merge tag 'exfat-for-6.8-rc1' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=179eff47e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=878a2a4af11180a7
dashboard link: https://syzkaller.appspot.com/bug?extid=db265923e3d158c61f80
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
CC: [ax...@kernel.dk linux...@vger.kernel.org linux-...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9085b1d0af36/disk-052d5343.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/dff804edb473/vmlinux-052d5343.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2a5cd81d366a/bzImage-052d5343.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+db2659...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in bdev_release+0x986/0xa80 block/bdev.c:956
Read of size 8 at addr ffff88807f389880 by task syz-executor.4/15389

CPU: 1 PID: 15389 Comm: syz-executor.4 Not tainted 6.7.0-syzkaller-09928-g052d534373b7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
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
bdev_release+0x986/0xa80 block/bdev.c:956
__btrfs_free_extra_devids+0x123/0x7a0 fs/btrfs/volumes.c:1019
btrfs_free_extra_devids+0x87/0x180 fs/btrfs/volumes.c:1046
open_ctree+0x1ebd/0x5430 fs/btrfs/disk-io.c:3388
btrfs_fill_super fs/btrfs/super.c:940 [inline]
btrfs_get_tree_super fs/btrfs/super.c:1852 [inline]
btrfs_get_tree+0x11e5/0x1b90 fs/btrfs/super.c:2078
vfs_get_tree+0x8c/0x370 fs/super.c:1784
fc_mount+0x16/0xc0 fs/namespace.c:1125
btrfs_get_tree_subvol fs/btrfs/super.c:2041 [inline]
btrfs_get_tree+0xa4f/0x1b90 fs/btrfs/super.c:2079
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: 0033:0x7fd62c67e4aa
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 09 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd62d3b8ef8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd62d3b8f80 RCX: 00007fd62c67e4aa
RDX: 00000000200051c0 RSI: 0000000020005200 RDI: 00007fd62d3b8f40
RBP: 00000000200051c0 R08: 00007fd62d3b8f80 R09: 0000000001000008
R10: 0000000001000008 R11: 0000000000000202 R12: 0000000020005200
R13: 00007fd62d3b8f40 R14: 00000000000051ab R15: 0000000020000280
</TASK>

Allocated by task 15227:
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]
ref_tracker_alloc+0x17c/0x5a0 lib/ref_tracker.c:203
__netdev_tracker_alloc include/linux/netdevice.h:4147 [inline]
netdev_hold include/linux/netdevice.h:4176 [inline]
netdev_hold include/linux/netdevice.h:4171 [inline]
inetdev_init+0x245/0x580 net/ipv4/devinet.c:282
inetdev_event+0x1191/0x19a0 net/ipv4/devinet.c:1555
notifier_call_chain+0xb6/0x3b0 kernel/notifier.c:93
call_netdevice_notifiers_info+0xbe/0x130 net/core/dev.c:1966
call_netdevice_notifiers_extack net/core/dev.c:2004 [inline]
call_netdevice_notifiers net/core/dev.c:2018 [inline]
register_netdevice+0x16e2/0x1da0 net/core/dev.c:10294
br_add_bridge+0x9a/0xe0 net/bridge/br_if.c:469
br_ioctl_stub+0x6af/0x8b0 net/bridge/br_ioctl.c:426
br_ioctl_call+0x62/0xb0 net/socket.c:1195
sock_ioctl+0x36d/0x6b0 net/socket.c:1295
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl fs/ioctl.c:857 [inline]
__x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857
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 15235:
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
ref_tracker_dir_exit+0x1eb/0x680 lib/ref_tracker.c:167
free_netdev+0x2fa/0x5f0 net/core/dev.c:10956
netdev_run_todo+0xd2b/0x12e0 net/core/dev.c:10575
br_ioctl_stub+0x247/0x8b0 net/bridge/br_ioctl.c:437
br_ioctl_call+0x62/0xb0 net/socket.c:1195
sock_ioctl+0x36d/0x6b0 net/socket.c:1295
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl fs/ioctl.c:857 [inline]
__x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857
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 ffff88807f389880
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
freed 32-byte region [ffff88807f389880, ffff88807f3898a0)

The buggy address belongs to the physical page:
page:ffffea0001fce240 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7f389
ksm flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000800 ffff888013041500 ffffea0000b4f540 dead000000000003
raw: 0000000000000000 0000000000200020 00000001ffffffff 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 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 5098, tgid 5098 (udevd), ts 2245821417374, free_ts 2245359350720
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+0x3b4/0x440 mm/slub.c:3994
kmalloc include/linux/slab.h:594 [inline]
kzalloc include/linux/slab.h:711 [inline]
tomoyo_encode2+0x100/0x3d0 security/tomoyo/realpath.c:45
tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80
tomoyo_realpath_from_path+0x196/0x710 security/tomoyo/realpath.c:283
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x26f/0x450 security/tomoyo/file.c:822
security_inode_getattr+0xf1/0x150 security/security.c:2237
vfs_getattr+0x36/0xa0 fs/stat.c:173
vfs_statx+0x171/0x550 fs/stat.c:248
vfs_fstatat+0xb3/0x140 fs/stat.c:304
__do_sys_newfstatat+0x98/0x110 fs/stat.c:468
page last free pid 5619 tgid 5619 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_list+0xe6/0xb40 mm/page_alloc.c:2532
release_pages+0x32a/0x14f0 mm/swap.c:1042
__folio_batch_release+0x77/0xe0 mm/swap.c:1062
folio_batch_release include/linux/pagevec.h:83 [inline]
truncate_inode_pages_range+0x33e/0xf00 mm/truncate.c:362
kill_bdev block/bdev.c:79 [inline]
blkdev_flush_mapping+0x144/0x310 block/bdev.c:638
blkdev_put_whole+0xb9/0xe0 block/bdev.c:669
bdev_release+0x509/0xa80 block/bdev.c:985
blkdev_release+0x37/0x50 block/fops.c:631
__fput+0x270/0xb70 fs/file_table.c:376
__fput_sync+0x47/0x50 fs/file_table.c:461
__do_sys_close fs/open.c:1554 [inline]
__se_sys_close fs/open.c:1539 [inline]
__x64_sys_close+0x87/0xf0 fs/open.c:1539
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

Memory state around the buggy address:
ffff88807f389780: fa fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
ffff88807f389800: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88807f389880: fa fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff88807f389900: fa fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
ffff88807f389980: fa fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.