syzbot


WARNING in lookup_slow (4)

Status: moderation: reported on 2025/05/26 09:57
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+2b8d9d5c6bae92cffb1d@syzkaller.appspotmail.com
First crash: 154d, last: 10d
Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in lookup_slow (2) -1 1 722d 722d 0/3 auto-obsoleted due to no activity on 2024/02/09 08:58
upstream WARNING in lookup_slow (2) fs -1 8 497d 528d 0/29 auto-obsoleted due to no activity on 2024/09/12 01:16
linux-6.1 WARNING in lookup_slow origin:upstream missing-backport -1 C inconclusive 9 71d 691d 0/3 upstream: reported C repro on 2023/12/02 22:03
upstream WARNING in lookup_slow (3) fs -1 1 304d 300d 0/29 auto-obsoleted due to no activity on 2025/02/21 12:31
linux-5.15 WARNING in lookup_slow (3) origin:lts-only -1 C error 7 16d 572d 0/3 upstream: reported C repro on 2024/03/30 12:27
upstream WARNING in lookup_slow ntfs3 -1 C error inconclusive 34 639d 1039d 0/29 auto-obsoleted due to no activity on 2024/05/02 19:30
linux-5.15 WARNING in lookup_slow -1 1 882d 882d 0/3 auto-obsoleted due to no activity on 2023/09/02 18:27

Sample crash report:
------------[ cut here ]------------
DEBUG_RWSEMS_WARN_ON(tmp < 0): count = 0xffffffffffffff00, magic = 0xffff888042f8d058, owner = 0x0, curr 0xffff88801f9e8000, list empty
WARNING: CPU: 0 PID: 5324 at kernel/locking/rwsem.c:1359 __up_read+0x3ea/0x680 kernel/locking/rwsem.c:1359
Modules linked in:
CPU: 0 UID: 0 PID: 5324 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__up_read+0x3ea/0x680 kernel/locking/rwsem.c:1359
Code: d0 48 c7 c7 20 ff 6a 8b 48 c7 c6 20 01 6b 8b 48 8b 54 24 08 48 8b 0c 24 4d 89 f8 4d 89 f1 41 52 e8 fb 3c e6 ff 48 83 c4 08 90 <0f> 0b 90 90 e9 71 fe ff ff c6 05 d4 18 eb 0d 01 90 48 89 df be 08
RSP: 0018:ffffc9000d57f940 EFLAGS: 00010292
RAX: cdf8f9fa1a8ff900 RBX: ffff888042f8d058 RCX: ffff88801f9e8000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc9000d57f9f8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa650 R12: ffffffffffffff00
R13: ffff888042f8d0b0 R14: ffff88801f9e8000 R15: 0000000000000000
FS:  00007f6d8e65f6c0(0000) GS:ffff88808d301000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6d8e65efc8 CR3: 000000003e9f3000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 inode_unlock_shared include/linux/fs.h:1005 [inline]
 lookup_slow+0x5e/0x70 fs/namei.c:1834
 walk_component fs/namei.c:2151 [inline]
 link_path_walk+0x935/0xea0 fs/namei.c:2519
 path_parentat fs/namei.c:2723 [inline]
 __filename_parentat+0x246/0x670 fs/namei.c:2747
 filename_parentat fs/namei.c:2765 [inline]
 filename_create+0xd2/0x3c0 fs/namei.c:4207
 do_mkdirat+0xa0/0x590 fs/namei.c:4478
 __do_sys_mkdirat fs/namei.c:4503 [inline]
 __se_sys_mkdirat fs/namei.c:4501 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6d8d78eec9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6d8e65f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f6d8d9e6180 RCX: 00007f6d8d78eec9
RDX: 0000000000000000 RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f6d8d811f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6d8d9e6218 R14: 00007f6d8d9e6180 R15: 00007fff9941e3b8
 </TASK>

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/13 21:30 upstream 3a8660878839 b6605ba8 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in lookup_slow
2025/09/08 17:33 upstream 76eeb9b8de98 d291dd2d .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in lookup_slow
2025/08/10 12:23 upstream 561c80369df0 32a0e5ed .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in lookup_slow
2025/07/22 23:02 upstream 89be9a83ccf1 af30dea9 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in lookup_slow
2025/07/11 14:08 upstream bc9ff192a6c9 3cda49cf .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in lookup_slow
2025/06/25 14:44 upstream 7595b66ae9de 26d77996 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in lookup_slow
2025/06/19 09:02 upstream fb4d33ab452e ed3e87f7 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in lookup_slow
2025/05/30 12:38 upstream f66bc387efbe 3d2f584d .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in lookup_slow
2025/05/22 09:52 upstream d608703fcdd9 0919b50b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in lookup_slow
* Struck through repros no longer work on HEAD.