syzbot


WARNING in do_mknodat (4)

Status: upstream: reported on 2025/09/25 13:41
Reported-by: syzbot+29572efcebf7888f6bb6@syzkaller.appspotmail.com
First crash: 146d, last: 1d13h
Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in do_mknodat fs -1 1 1153d 1098d 0/29 closed as invalid on 2023/02/16 16:02
upstream WARNING in do_mknodat (3) gfs2 -1 C 240 10d 187d 0/29 upstream: reported C repro on 2025/08/15 07:21
linux-6.1 WARNING in do_mknodat -1 1 839d 839d 0/3 auto-obsoleted due to no activity on 2024/02/10 13:02
upstream WARNING in do_mknodat (2) fs -1 11 823d 1091d 0/29 auto-obsoleted due to no activity on 2024/02/16 05:28
linux-5.15 WARNING in do_mknodat (4) origin:upstream -1 C inconclusive 7 53d 281d 0/3 upstream: reported C repro on 2025/05/12 19:05
linux-6.1 WARNING in do_mknodat (2) -1 39 606d 673d 0/3 auto-obsoleted due to no activity on 2024/08/30 19:08
linux-5.15 WARNING in do_mknodat (3) -1 7 391d 488d 0/3 auto-obsoleted due to no activity on 2025/05/02 18:42
linux-6.1 WARNING in do_mknodat (3) -1 27 290d 500d 0/3 auto-obsoleted due to no activity on 2025/08/12 05:18
linux-5.15 WARNING in do_mknodat (2) -1 4 627d 804d 0/3 auto-obsoleted due to no activity on 2024/09/08 20:03
linux-5.15 WARNING in do_mknodat -1 1 916d 916d 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 = 0xffff88805579ea70, owner = 0x0, curr 0xffff888027ad8000, list empty
WARNING: CPU: 1 PID: 6687 at kernel/locking/rwsem.c:1372 __up_write kernel/locking/rwsem.c:1371 [inline]
WARNING: CPU: 1 PID: 6687 at kernel/locking/rwsem.c:1372 up_write+0x3a1/0x420 kernel/locking/rwsem.c:1626
Modules linked in:
CPU: 1 PID: 6687 Comm: syz.3.751 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__up_write kernel/locking/rwsem.c:1371 [inline]
RIP: 0010:up_write+0x3a1/0x420 kernel/locking/rwsem.c:1626
Code: 44 d0 48 c7 c7 a0 05 8c 8a 48 c7 c6 e0 07 8c 8a 48 8b 14 24 4c 89 f1 4d 89 e0 4c 8b 4c 24 08 41 52 e8 f3 30 ea ff 48 83 c4 08 <0f> 0b e9 6b fd ff ff 48 c7 c1 e8 00 20 8e 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc9000540fdb0 EFLAGS: 00010292
RAX: 3d8e1a71da0b5500 RBX: ffff88805579ea70 RCX: 0000000000080000
RDX: ffffc9000cf49000 RSI: 00000000000202f0 RDI: 00000000000202f1
RBP: dffffc0000000000 R08: ffffc9000540fa27 R09: 1ffff92000a81f44
R10: dffffc0000000000 R11: fffff52000a81f45 R12: 0000000000000000
R13: ffff88805579eac8 R14: ffff88805579ea70 R15: 1ffff1100aaf3d4f
FS:  00007ff74b5ac6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff7485d3d58 CR3: 000000007e45e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 inode_unlock include/linux/fs.h:763 [inline]
 done_path_create fs/namei.c:3935 [inline]
 do_mknodat+0x40c/0x4d0 fs/namei.c:4058
 __do_sys_mknodat fs/namei.c:4071 [inline]
 __se_sys_mknodat fs/namei.c:4068 [inline]
 __x64_sys_mknodat+0xa5/0xc0 fs/namei.c:4068
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff74a79bf79
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff74b5ac028 EFLAGS: 00000246 ORIG_RAX: 0000000000000103
RAX: ffffffffffffffda RBX: 00007ff74aa15fa0 RCX: 00007ff74a79bf79
RDX: 00000000000081c0 RSI: 0000200000000180 RDI: ffffffffffffff9c
RBP: 00007ff74a8327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff74aa16038 R14: 00007ff74aa15fa0 R15: 00007ffcb7bbbd18
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/17 01:42 linux-6.1.y 8ce36b2849ef 5d52cba5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in do_mknodat
2026/01/06 19:45 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in do_mknodat
2025/12/30 02:18 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in do_mknodat
2025/10/12 06:55 linux-6.1.y 882efbdd9d34 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in do_mknodat
2025/09/25 13:41 linux-6.1.y 7b34dc04e4ff 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in do_mknodat
* Struck through repros no longer work on HEAD.