WARNING in drop_nlink

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: a1b977b4 Linux 4.19.150
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11e80420500000
kernel config: https://syzkaller.appspot.com/x/.config?x=c14008c8da1ca4d4
dashboard link: https://syzkaller.appspot.com/bug?extid=b9b916c5af0009d5a2ef
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1767c5d0500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=126242bf900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b9b916...@syzkaller.appspotmail.com

audit: type=1400 audit(1602150728.581:8): avc: denied { execmem } for pid=6478 comm="syz-executor499" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1
MINIX-fs: mounting unchecked file system, running fsck is recommended
------------[ cut here ]------------
WARNING: CPU: 0 PID: 6478 at fs/inode.c:286 drop_nlink.cold+0x11/0x41 fs/inode.c:286
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 6478 Comm: syz-executor499 Not tainted 4.19.150-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x22c/0x33e lib/dump_stack.c:118
panic+0x2ac/0x565 kernel/panic.c:186
__warn.cold+0x20/0x5a kernel/panic.c:541
report_bug+0x262/0x2b0 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:178 [inline]
fixup_bug arch/x86/kernel/traps.c:173 [inline]
do_error_trap+0x1e1/0x330 arch/x86/kernel/traps.c:296
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038
RIP: 0010:drop_nlink.cold+0x11/0x41 fs/inode.c:286
Code: e0 5d 41 5c c3 e8 e6 25 ee ff e9 6e ff ff ff e8 6c 26 ee ff e9 32 ff ff ff e8 62 d7 b4 ff 48 c7 c7 80 0f 16 88 e8 05 53 9e ff <0f> 0b b8 ff ff 37 00 4c 89 e2 48 c1 ea 03 48 c1 e0 2a 0f b6 04 02
RSP: 0018:ffff8880a755fb08 EFLAGS: 00010286
RAX: 0000000000000024 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815b623f RDI: ffffed1014eabf53
RBP: ffff8880800280c0 R08: 0000000000000024 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff888080028108
R13: 0000000000000000 R14: ffff8880800280c0 R15: ffff88808002a9e0
inode_dec_link_count include/linux/fs.h:2108 [inline]
minix_rename+0x3e6/0x8d0 fs/minix/namei.c:226
vfs_rename+0x67e/0x1910 fs/namei.c:4479
do_renameat2+0xb4c/0xc70 fs/namei.c:4629
__do_sys_renameat fs/namei.c:4670 [inline]
__se_sys_renameat fs/namei.c:4667 [inline]
__x64_sys_renameat+0x96/0x100 fs/namei.c:4667
do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x444729
Code: 8d d7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 5b d7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffeca48e6c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000108
RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000444729
RDX: 0000000000000009 RSI: 0000000020000500 RDI: 000000000000000a
RBP: 00000000006d0018 R08: 00000000004002e0 R09: 00000000004002e0
R10: 00000000200017c0 R11: 0000000000000246 R12: 0000000000402310
R13: 00000000004023a0 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..


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