WARNING in cramfs_kill_sb

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: cf256fbc Linux 4.14.231
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16e0eb29d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=403e68efdb1dcca6
dashboard link: https://syzkaller.appspot.com/bug?extid=16258a45157926586af3

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+16258a...@syzkaller.appspotmail.com

blkdev_get_by_path+0x1b/0xa0 fs/block_dev.c:1688
mount_bdev+0x4c/0x360 fs/super.c:1092
------------[ cut here ]------------
mount_fs+0x92/0x2a0 fs/super.c:1237
WARNING: CPU: 0 PID: 17087 at fs/super.c:1163 kill_block_super+0xbe/0xe0 fs/super.c:1163
vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
Kernel panic - not syncing: panic_on_warn set ...

vfs_kern_mount fs/namespace.c:1036 [inline]
do_new_mount fs/namespace.c:2549 [inline]
do_mount+0xe53/0x2a00 fs/namespace.c:2879
SYSC_mount fs/namespace.c:3095 [inline]
SyS_mount+0xa8/0x120 fs/namespace.c:3072
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x466459
RSP: 002b:00007f2ef76f8188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459
RDX: 0000000020000200 RSI: 00000000200001c0 RDI: 0000000020000000
RBP: 00007f2ef76f81d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fffb6f84dcf R14: 00007f2ef76f8300 R15: 0000000000022000
CPU: 0 PID: 17087 Comm: syz-executor.1 Not tainted 4.14.231-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x1b2/0x281 lib/dump_stack.c:58
panic+0x1f9/0x42d kernel/panic.c:183
__warn.cold+0x20/0x44 kernel/panic.c:547
report_bug+0x208/0x250 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:177 [inline]
fixup_bug arch/x86/kernel/traps.c:172 [inline]
do_error_trap+0x195/0x2d0 arch/x86/kernel/traps.c:295
invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:964
RIP: 0010:kill_block_super+0xbe/0xe0 fs/super.c:1163
RSP: 0018:ffff888095047bb0 EFLAGS: 00010246
RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc900066df000
RDX: 0000000000040000 RSI: ffffffff818726fe RDI: ffff88808feff530
RBP: ffff888098d140c0 R08: ffffffff8b9b79f0 R09: 0000000000000001
R10: 0000000000000000 R11: ffff888090f6a5c0 R12: ffff88808feff080
R13: ffffffff890a2130 R14: ffffffff88f44f40 R15: dffffc0000000000
cramfs_kill_sb+0x38/0x50 fs/cramfs/inode.c:247
deactivate_locked_super+0x6c/0xd0 fs/super.c:319
sget_userns+0x9c4/0xc10 fs/super.c:537
sget+0xd1/0x110 fs/super.c:572
mount_bdev+0xcd/0x360 fs/super.c:1107
mount_fs+0x92/0x2a0 fs/super.c:1237
vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
vfs_kern_mount fs/namespace.c:1036 [inline]
do_new_mount fs/namespace.c:2549 [inline]
do_mount+0xe53/0x2a00 fs/namespace.c:2879
SYSC_mount fs/namespace.c:3095 [inline]
SyS_mount+0xa8/0x120 fs/namespace.c:3072
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x466459
RSP: 002b:00007f750c30d188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459
RDX: 0000000020000200 RSI: 00000000200001c0 RDI: 0000000020000000
RBP: 00007f750c30d1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 00007fff11f8c5af R14: 00007f750c30d300 R15: 0000000000022000
Kernel Offset: disabled
Rebooting in 86400 seconds..


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[syzbot]

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