syzbot


WARNING in do_mknodat (4)

Status: upstream: reported on 2025/09/25 13:41
Reported-by: syzbot+29572efcebf7888f6bb6@syzkaller.appspotmail.com
First crash: 1d01h, last: 1d01h
Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in do_mknodat fs -1 1 1008d 953d 0/29 closed as invalid on 2023/02/16 16:02
upstream WARNING in do_mknodat (3) gfs2 -1 C 192 18h25m 42d 0/29 upstream: reported C repro on 2025/08/15 07:21
linux-6.1 WARNING in do_mknodat -1 1 694d 694d 0/3 auto-obsoleted due to no activity on 2024/02/10 13:02
upstream WARNING in do_mknodat (2) fs -1 11 678d 946d 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 7 14d 136d 0/3 upstream: reported C repro on 2025/05/12 19:05
linux-6.1 WARNING in do_mknodat (2) -1 39 461d 528d 0/3 auto-obsoleted due to no activity on 2024/08/30 19:08
linux-5.15 WARNING in do_mknodat (3) -1 7 246d 343d 0/3 auto-obsoleted due to no activity on 2025/05/02 18:42
linux-6.1 WARNING in do_mknodat (3) -1 27 145d 355d 0/3 auto-obsoleted due to no activity on 2025/08/12 05:18
linux-5.15 WARNING in do_mknodat (2) -1 4 482d 660d 0/3 auto-obsoleted due to no activity on 2024/09/08 20:03
linux-5.15 WARNING in do_mknodat -1 1 771d 771d 0/3 auto-obsoleted due to no activity on 2023/11/25 05:54

Sample crash report:
------------[ cut here ]------------
DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff0000f6434ac8, owner = 0x0, curr 0xffff0000d35c5340, list empty
WARNING: CPU: 1 PID: 4539 at kernel/locking/rwsem.c:1372 __up_write kernel/locking/rwsem.c:1371 [inline]
WARNING: CPU: 1 PID: 4539 at kernel/locking/rwsem.c:1372 up_write+0x494/0x5c0 kernel/locking/rwsem.c:1626
Modules linked in:
CPU: 1 PID: 4539 Comm: syz.4.19 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : __up_write kernel/locking/rwsem.c:1371 [inline]
pc : up_write+0x494/0x5c0 kernel/locking/rwsem.c:1626
lr : __up_write kernel/locking/rwsem.c:1371 [inline]
lr : up_write+0x494/0x5c0 kernel/locking/rwsem.c:1626
sp : ffff800021277c00
x29: ffff800021277c10 x28: 0000000000000000 x27: ffff8000151436e0
x26: dfff800000000000 x25: 1fffe0001ec86966 x24: ffff0000f6434b20
x23: 0000000000000000 x22: 0000000000000000 x21: ffff0000d35c5340
x20: ffff0000f6434ac8 x19: ffff0000f6434ac8 x18: ffff800011abbcc0
x17: 0000000000000000 x16: ffff8000082d22e0 x15: 0000000000000002
x14: 00000000ffffffff x13: 0000000000000001 x12: 0000000000080000
x11: 0000000000017c44 x10: ffff80002b004000 x9 : f59421c09c580a00
x8 : f59421c09c580a00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800021277698 x4 : ffff8000151a4820 x3 : ffff80000852e158
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000000
Call trace:
 __up_write kernel/locking/rwsem.c:1371 [inline]
 up_write+0x494/0x5c0 kernel/locking/rwsem.c:1626
 inode_unlock include/linux/fs.h:763 [inline]
 done_path_create fs/namei.c:3927 [inline]
 do_mknodat+0x3bc/0x54c fs/namei.c:4050
 __do_sys_mknodat fs/namei.c:4063 [inline]
 __se_sys_mknodat fs/namei.c:4060 [inline]
 __arm64_sys_mknodat+0xb0/0xcc fs/namei.c:4060
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
irq event stamp: 494
hardirqs last  enabled at (493): [<ffff800008308424>] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:261
hardirqs last disabled at (494): [<ffff8000119594a8>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last  enabled at (488): [<ffff8000081a967c>] softirq_handle_end kernel/softirq.c:439 [inline]
softirqs last  enabled at (488): [<ffff8000081a967c>] handle_softirqs+0xaf8/0xc6c kernel/softirq.c:624
softirqs last disabled at (287): [<ffff800008020164>] __do_softirq+0x14/0x20 kernel/softirq.c:630
---[ end trace 0000000000000000 ]---

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.