general protection fault in kernfs_find_ns

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 7a5b4ac2 ANDROID: GKI: genksyms fixup for efed9a3337e3 ("k..
git tree: android12-5.4
console output: https://syzkaller.appspot.com/x/log.txt?x=145704f3d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=33a242af3161f30e
dashboard link: https://syzkaller.appspot.com/bug?extid=dfe2cfd9588c8465c51c
compiler: Debian clang version 11.0.1-2

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+dfe2cf...@syzkaller.appspotmail.com

R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffeadde39ef R14: 00007f22dd03e300 R15: 0000000000022000
---[ end trace 53f3cdce47d144c0 ]---
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 1234 Comm: syz-executor.3 Tainted: G W 5.4.120-syzkaller-00694-g7a5b4ac26db4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:strlen+0x27/0x60 lib/string.c:551
Code: 0f 1f 00 41 57 41 56 53 49 89 fe 49 bf 00 00 00 00 00 fc ff df 48 89 f8 66 66 2e 0f 1f 84 00 00 00 00 00 48 89 c3 48 c1 e8 03 <42> 0f b6 04 38 84 c0 75 0b 48 8d 43 01 80 3b 00 75 e7 eb 13 89 d9
RSP: 0018:ffff8881ef5ffa18 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000200001
RDX: 0000000000200000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff81b9d03b R09: 000000000000ffff
R10: ffffc90003da6000 R11: 0000000000000000 R12: ffff8881f1ada840
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS: 00007f22dd03e700(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fde722dc710 CR3: 00000001e4826000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
kernfs_name_hash fs/kernfs/dir.c:302 [inline]
kernfs_find_ns+0x83/0x430 fs/kernfs/dir.c:847
kernfs_remove_by_name_ns+0x32/0x90 fs/kernfs/dir.c:1510
del_gendisk+0x996/0xbf0 block/genhd.c:833
loop_remove drivers/block/loop.c:2186 [inline]
loop_control_ioctl+0x6a3/0x7c0 drivers/block/loop.c:2285
do_vfs_ioctl+0x76a/0x1720 fs/ioctl.c:47
ksys_ioctl fs/ioctl.c:742 [inline]
__do_sys_ioctl fs/ioctl.c:749 [inline]
__se_sys_ioctl fs/ioctl.c:747 [inline]
__x64_sys_ioctl+0xd4/0x110 fs/ioctl.c:747
do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f22dd03e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000004
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffeadde39ef R14: 00007f22dd03e300 R15: 0000000000022000
Modules linked in:
---[ end trace 53f3cdce47d144c1 ]---
RIP: 0010:strlen+0x27/0x60 lib/string.c:551
Code: 0f 1f 00 41 57 41 56 53 49 89 fe 49 bf 00 00 00 00 00 fc ff df 48 89 f8 66 66 2e 0f 1f 84 00 00 00 00 00 48 89 c3 48 c1 e8 03 <42> 0f b6 04 38 84 c0 75 0b 48 8d 43 01 80 3b 00 75 e7 eb 13 89 d9
RSP: 0018:ffff8881ef5ffa18 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000200001
RDX: 0000000000200000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff81b9d03b R09: 000000000000ffff
R10: ffffc90003da6000 R11: 0000000000000000 R12: ffff8881f1ada840
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS: 00007f22dd03e700(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fde722dc710 CR3: 00000001e4826000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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[syzbot]

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