syzbot


WARNING in do_mknodat (4)

Status: upstream: reported syz repro on 2025/05/12 19:05
Reported-by: syzbot+d5e7caced7e104629877@syzkaller.appspotmail.com
First crash: 55d, last: 16d
Bug presence (1)
Date Name Commit Repro Result
2025/05/29 upstream (ToT) 90b83efa6701 C Didn't crash
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in do_mknodat fs 1 927d 872d 0/29 closed as invalid on 2023/02/16 16:02
upstream WARNING in do_mknodat (3) fs 175 18d 493d 0/29 moderation: reported on 2024/03/01 11:23
linux-6.1 WARNING in do_mknodat 1 613d 613d 0/3 auto-obsoleted due to no activity on 2024/02/10 13:02
upstream WARNING in do_mknodat (2) fs 11 597d 865d 0/29 auto-obsoleted due to no activity on 2024/02/16 05:28
linux-6.1 WARNING in do_mknodat (2) 39 380d 447d 0/3 auto-obsoleted due to no activity on 2024/08/30 19:08
linux-5.15 WARNING in do_mknodat (3) 7 165d 262d 0/3 auto-obsoleted due to no activity on 2025/05/02 18:42
linux-6.1 WARNING in do_mknodat (3) 27 64d 274d 0/3 upstream: reported on 2024/10/06 10:51
linux-5.15 WARNING in do_mknodat (2) 4 401d 578d 0/3 auto-obsoleted due to no activity on 2024/09/08 20:03
linux-5.15 WARNING in do_mknodat 1 690d 690d 0/3 auto-obsoleted due to no activity on 2023/11/25 05:54

Sample crash report:
DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff8880598bf1d0, owner = 0x0, curr 0xffff888027e38000, list empty
WARNING: CPU: 0 PID: 5922 at kernel/locking/rwsem.c:1350 __up_write kernel/locking/rwsem.c:1349 [inline]
WARNING: CPU: 0 PID: 5922 at kernel/locking/rwsem.c:1350 up_write+0x3a1/0x420 kernel/locking/rwsem.c:1604
Modules linked in:
CPU: 0 PID: 5922 Comm: syz.6.378 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__up_write kernel/locking/rwsem.c:1349 [inline]
RIP: 0010:up_write+0x3a1/0x420 kernel/locking/rwsem.c:1604
Code: 44 d0 48 c7 c7 40 05 0b 8a 48 c7 c6 00 08 0b 8a 48 8b 14 24 4c 89 f1 4d 89 e0 4c 8b 4c 24 08 41 52 e8 33 65 3b 08 48 83 c4 08 <0f> 0b e9 6b fd ff ff 48 c7 c1 88 df 68 8d 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc90003affdb0 EFLAGS: 00010292
RAX: d2b2ce6c8cbc8300 RBX: ffff8880598bf1d0 RCX: 0000000000080000
RDX: ffffc9001377b000 RSI: 0000000000021142 RDI: 0000000000021143
RBP: dffffc0000000000 R08: dffffc0000000000 R09: ffffed10172067a8
R10: ffffed10172067a8 R11: 1ffff110172067a7 R12: 0000000000000000
R13: ffff8880598bf228 R14: ffff8880598bf1d0 R15: 1ffff1100b317e3b
FS:  00007ffa829bb6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563621691950 CR3: 0000000058e53000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 inode_unlock include/linux/fs.h:792 [inline]
 done_path_create fs/namei.c:3886 [inline]
 do_mknodat+0x408/0x620 fs/namei.c:4009
 __do_sys_mknodat fs/namei.c:4022 [inline]
 __se_sys_mknodat fs/namei.c:4019 [inline]
 __x64_sys_mknodat+0xa5/0xc0 fs/namei.c:4019
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ffa84b74929
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:00007ffa829bb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000103
RAX: ffffffffffffffda RBX: 00007ffa84d9c080 RCX: 00007ffa84b74929
RDX: 0000000000000000 RSI: 0000200000000340 RDI: 0000000000000004
RBP: 00007ffa84bf6b39 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000070c R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ffa84d9c080 R15: 00007ffcb9897c78
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/20 15:11 linux-5.15.y 1c700860e8bc 804b3919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in do_mknodat
2025/05/26 06:31 linux-5.15.y 98f47d0e9b8c 2d4582d0 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan WARNING in do_mknodat
2025/05/12 19:04 linux-5.15.y 3b8db0e4f263 f6671af7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING in do_mknodat
* Struck through repros no longer work on HEAD.