WARNING in qnx4_kill_sb

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2762b48e Linux 4.14.216
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16c1bf94d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=e8574522d7c28056
dashboard link: https://syzkaller.appspot.com/bug?extid=c45bf62ba2c3aa90d77d
compiler: gcc (GCC) 10.1.0-syz 20200507

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+c45bf6...@syzkaller.appspotmail.com

__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x1b2/0x281 lib/dump_stack.c:58
fail_dump lib/fault-inject.c:51 [inline]
should_fail.cold+0x10a/0x149 lib/fault-inject.c:149
should_failslab+0xd6/0x130 mm/failslab.c:32
slab_pre_alloc_hook mm/slab.h:421 [inline]
slab_alloc mm/slab.c:3376 [inline]
__do_kmalloc mm/slab.c:3718 [inline]
__kmalloc_track_caller+0x2bc/0x400 mm/slab.c:3735
------------[ cut here ]------------
WARNING: CPU: 0 PID: 13636 at fs/super.c:1163 kill_block_super+0xbe/0xe0 fs/super.c:1163
kstrdup+0x36/0x70 mm/util.c:56
Kernel panic - not syncing: panic_on_warn set ...

kstrdup_const+0x35/0x60 mm/util.c:77
alloc_vfsmnt+0xe0/0x7f0 fs/namespace.c:214
vfs_kern_mount.part.0+0x27/0x470 fs/namespace.c:1039
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: 0033:0x460c6a
RSP: 002b:00007fde0ed28a78 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fde0ed28b10 RCX: 0000000000460c6a
RDX: 00000000200004c0 RSI: 0000000020000500 RDI: 00007fde0ed28ad0
RBP: 00007fde0ed28ad0 R08: 00007fde0ed28b10 R09: 00000000200004c0
R10: 0000000000008080 R11: 0000000000000202 R12: 00000000200004c0
R13: 0000000020000500 R14: 0000000020000a40 R15: 0000000020000b00
CPU: 0 PID: 13636 Comm: syz-executor.3 Not tainted 4.14.216-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:ffff888062367bb0 EFLAGS: 00010246
RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc900088c8000
RDX: 0000000000040000 RSI: ffffffff8186f5ae RDI: ffff8880b1f7abb0
RBP: ffff8880626b6140 R08: ffffffff8b999ff8 R09: 0000000000000001
R10: 0000000000000000 R11: ffff88806191a500 R12: ffff8880b1f7a700
R13: ffffffff891e0870 R14: ffffffff88f44f00 R15: dffffc0000000000
qnx4_kill_sb+0x38/0x90 fs/qnx4/inode.c:239
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: 0033:0x460c6a
RSP: 002b:00007f00dc4faa78 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f00dc4fab10 RCX: 0000000000460c6a
RDX: 00000000200004c0 RSI: 0000000020000500 RDI: 00007f00dc4faad0
RBP: 00007f00dc4faad0 R08: 00007f00dc4fab10 R09: 00000000200004c0
R10: 0000000000008080 R11: 0000000000000202 R12: 00000000200004c0
R13: 0000000020000500 R14: 0000000020000a40 R15: 0000000020000b00
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
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:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

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