[syzbot] [ext4?] WARNING in mb_cache_destroy

syzbot
2024-04-30T07:19:23Z

Hello,

syzbot found the following issue on:

HEAD commit: b947cc5bf6d7 Merge tag 'erofs-for-6.9-rc7-fixes' of git://..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=11175d5f180000
kernel config: https://syzkaller.appspot.com/x/.config?x=d2f00edef461175
dashboard link: https://syzkaller.appspot.com/bug?extid=dd43bd0f7474512edc47
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11d2957f180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1620ca40980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7318118d629d/disk-b947cc5b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/88b2ce2fc8ea/vmlinux-b947cc5b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3f3ffc239871/bzImage-b947cc5b.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/224b657d209f/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+dd43bd0f7474512edc47@syzkaller.appspotmail.com

loop0: detected capacity change from 512 to 64
EXT4-fs (loop0): unmounting filesystem 00000000-0000-0000-0000-000000000000.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290 fs/mbcache.c:419
Modules linked in:
CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-syzkaller-00005-gb947cc5bf6d7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419
Code: 24 08 4c 89 f6 e8 9c e6 ff ff eb 05 e8 45 3b 6e ff 4c 8b 34 24 49 39 ee 74 33 e8 37 3b 6e ff e9 6a fe ff ff e8 2d 3b 6e ff 90 <0f> 0b 90 eb 83 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c 58 ff ff ff
RSP: 0018:ffffc90003677a88 EFLAGS: 00010293
RAX: ffffffff8227d393 RBX: 0000000000000002 RCX: ffff88807c9ebc00
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000001
RBP: ffff88801aeb3858 R08: ffffffff8227d312 R09: 1ffff1100dd2e204
R10: dffffc0000000000 R11: ffffed100dd2e205 R12: 1ffff1100dd2e200
R13: ffff88806e971020 R14: ffff88806e971000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ec96f85460 CR3: 000000000e134000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ext4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375
generic_shutdown_super+0x136/0x2d0 fs/super.c:641
kill_block_super+0x44/0x90 fs/super.c:1675
ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327
deactivate_locked_super+0xc4/0x130 fs/super.c:472
cleanup_mnt+0x426/0x4c0 fs/namespace.c:1267
task_work_run+0x24f/0x310 kernel/task_work.c:180
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0xa1b/0x27e0 kernel/exit.c:878
do_group_exit+0x207/0x2c0 kernel/exit.c:1027
__do_sys_exit_group kernel/exit.c:1038 [inline]
__se_sys_exit_group kernel/exit.c:1036 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4207bbec89
Code: Unable to access opcode bytes at 0x7f4207bbec5f.
RSP: 002b:00007ffd518b18c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4207bbec89
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001
RBP: 00007f4207c3b390 R08: ffffffffffffffb8 R09: 00007ffd518b19a0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4207c3b390
R13: 0000000000000000 R14: 00007f4207c3c100 R15: 00007f4207b8cf60
</TASK>

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