general protection fault in idr_remove (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: a581387e Merge tag 'io_uring-5.8-2020-07-10' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1135d463100000
kernel config: https://syzkaller.appspot.com/x/.config?x=66ad203c2bb6d8b
dashboard link: https://syzkaller.appspot.com/bug?extid=57e2087e595b699e856e
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+57e208...@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc000000000c: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067]
CPU: 0 PID: 32496 Comm: systemd-udevd Not tainted 5.8.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:idr_remove+0x22/0x50 lib/idr.c:154
Code: 0f 1f 84 00 00 00 00 00 55 48 89 fd 53 48 89 f3 e8 13 1e c6 fd 48 8d 7d 50 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 3c 03 7e 15 8b 45 50 48 89 ef 31 d2 48 29
RSP: 0018:ffffc90016eef540 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000025411 RCX: ffffffff815afc00
RDX: 000000000000000c RSI: ffffffff83ad997d RDI: 0000000000000060
RBP: 0000000000000010 R08: 0000000000000001 R09: 0000000000000003
R10: fffff52002ddde9d R11: 0000000000000000 R12: ffff88809125a488
R13: ffff88801f6243e0 R14: ffff88809125a4c0 R15: 0000000080000001
FS: 00007fdae029e8c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdadf1a006c CR3: 00000000a2028000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
kernfs_put.part.0+0x294/0x540 fs/kernfs/dir.c:535
kernfs_put+0x42/0x50 fs/kernfs/dir.c:511
evict+0x2ed/0x750 fs/inode.c:576
iput_final fs/inode.c:1652 [inline]
iput.part.0+0x424/0x850 fs/inode.c:1678
iput+0x58/0x70 fs/inode.c:1668
dentry_unlink_inode+0x2b1/0x3d0 fs/dcache.c:374
__dentry_kill+0x3c0/0x640 fs/dcache.c:579
shrink_dentry_list+0x144/0x480 fs/dcache.c:1141
shrink_dcache_parent+0x219/0x3c0 fs/dcache.c:1568
d_invalidate fs/dcache.c:1677 [inline]
d_invalidate+0x13f/0x280 fs/dcache.c:1662
lookup_fast+0x3ca/0x6c0 fs/namei.c:1509
walk_component+0xc6/0x6a0 fs/namei.c:1856
link_path_walk.part.0+0x6b8/0xc20 fs/namei.c:2183
link_path_walk fs/namei.c:2112 [inline]
path_openat+0x25a/0x2750 fs/namei.c:3356
do_filp_open+0x17e/0x3c0 fs/namei.c:3387
do_sys_openat2+0x16f/0x3b0 fs/open.c:1179
do_sys_open fs/open.c:1195 [inline]
ksys_open include/linux/syscalls.h:1388 [inline]
__do_sys_open fs/open.c:1201 [inline]
__se_sys_open fs/open.c:1199 [inline]
__x64_sys_open+0x119/0x1c0 fs/open.c:1199
do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fdadf1116f0
Code: Bad RIP value.
RSP: 002b:00007ffcb6cea898 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000556042e587c0 RCX: 00007fdadf1116f0
RDX: 00000000000001b6 RSI: 0000000000080000 RDI: 00007ffcb6ceaa40
RBP: 0000000000000008 R08: 0000000000000008 R09: 0000000000000001
R10: 0000000000080000 R11: 0000000000000246 R12: 0000556042d0f68a
R13: 0000000000000001 R14: 0000556042e58370 R15: 00007ffcb6ceaad0
Modules linked in:
---[ end trace 62f52bf15222f667 ]---
RIP: 0010:idr_remove+0x22/0x50 lib/idr.c:154
Code: 0f 1f 84 00 00 00 00 00 55 48 89 fd 53 48 89 f3 e8 13 1e c6 fd 48 8d 7d 50 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 3c 03 7e 15 8b 45 50 48 89 ef 31 d2 48 29
RSP: 0018:ffffc90016eef540 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000025411 RCX: ffffffff815afc00
RDX: 000000000000000c RSI: ffffffff83ad997d RDI: 0000000000000060
RBP: 0000000000000010 R08: 0000000000000001 R09: 0000000000000003
R10: fffff52002ddde9d R11: 0000000000000000 R12: ffff88809125a488
R13: ffff88801f6243e0 R14: ffff88809125a4c0 R15: 0000000080000001
FS: 00007fdae029e8c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdadf1a006c CR3: 00000000a2028000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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.