WARNING in minix_mkdir

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: a41ba30d Linux 4.14.181
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=10be3ce2100000
kernel config: https://syzkaller.appspot.com/x/.config?x=c5458e9cda81cf95
dashboard link: https://syzkaller.appspot.com/bug?extid=95d40aa89556f40288a0
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

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

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+95d40a...@syzkaller.appspotmail.com

__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x1b2/0x283 lib/dump_stack.c:58
fail_dump lib/fault-inject.c:51 [inline]
should_fail.cold+0x10a/0x154 lib/fault-inject.c:149
should_failslab+0xd6/0x130 mm/failslab.c:32
------------[ cut here ]------------
slab_pre_alloc_hook mm/slab.h:421 [inline]
slab_alloc mm/slab.c:3376 [inline]
kmem_cache_alloc+0x28e/0x3c0 mm/slab.c:3550
WARNING: CPU: 0 PID: 11934 at fs/inode.c:342 inc_nlink+0x113/0x130 fs/inode.c:342
kmem_cache_zalloc include/linux/slab.h:651 [inline]
file_alloc_security security/selinux/hooks.c:368 [inline]
selinux_file_alloc_security+0xaf/0x190 security/selinux/hooks.c:3475
Kernel panic - not syncing: panic_on_warn set ...

security_file_alloc+0x66/0xa0 security/security.c:874
get_empty_filp+0x15c/0x3e0 fs/file_table.c:129
path_openat+0x87/0x2aa0 fs/namei.c:3545
do_filp_open+0x18e/0x250 fs/namei.c:3603
do_sys_open+0x292/0x3e0 fs/open.c:1081
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x416821
RSP: 002b:00007fd09d0f9a60 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00000000005088c0 RCX: 0000000000416821
RDX: 00007fd09d0f9b0a RSI: 0000000000000002 RDI: 00007fd09d0f9b00
RBP: 000000000078bf00 R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000075 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000bea R14: 00000000004ce2a4 R15: 00007fd09d0fa6d4
CPU: 0 PID: 11934 Comm: syz-executor.5 Not tainted 4.14.181-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+0x1b2/0x283 lib/dump_stack.c:58
panic+0x1f9/0x42d kernel/panic.c:183
__warn.cold+0x2f/0x30 kernel/panic.c:547
report_bug+0x20a/0x248 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:inc_nlink+0x113/0x130 fs/inode.c:342
RSP: 0018:ffff8880558f7db0 EFLAGS: 00010212
RAX: 0000000000040000 RBX: ffff88808267f0c0 RCX: ffffc9000818b000
RDX: 00000000000009b1 RSI: ffffffff81912283 RDI: ffff88808267f198
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000002
R10: ffffed100ab1ef8e R11: 0000000000000003 R12: ffff88808267f108
R13: ffff888083b29600 R14: ffff888083b29658 R15: 0000000000000000
inode_inc_link_count include/linux/fs.h:2035 [inline]
minix_mkdir+0x5a/0x160 fs/minix/namei.c:121
vfs_mkdir+0x3af/0x620 fs/namei.c:3849
SYSC_mkdirat fs/namei.c:3872 [inline]
SyS_mkdirat+0x1b5/0x220 fs/namei.c:3856
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45ca29
RSP: 002b:00007ff987162c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00000000004f5b40 RCX: 000000000045ca29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000240
RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000734 R14: 00000000004c2500 R15: 00007ff9871636d4
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.