syzbot


WARNING in do_rmdir

Status: moderation: reported on 2025/04/21 00:40
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+5137233e6c55b3fe89dd@syzkaller.appspotmail.com
First crash: 266d, last: 8d11h

Sample crash report:
------------[ cut here ]------------
DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff8880466e5058, owner = 0x0, curr 0xffff888000e3a4c0, list empty
WARNING: kernel/locking/rwsem.c:1381 at __up_write kernel/locking/rwsem.c:1380 [inline], CPU#0: syz.0.0/5351
WARNING: kernel/locking/rwsem.c:1381 at up_write+0x2d8/0x410 kernel/locking/rwsem.c:1643, CPU#0: syz.0.0/5351
Modules linked in:
CPU: 0 UID: 0 PID: 5351 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_write kernel/locking/rwsem.c:1380 [inline]
RIP: 0010:up_write+0x38a/0x410 kernel/locking/rwsem.c:1643
Code: 6b 8b 49 c7 c2 c0 23 6b 8b 4c 0f 44 d0 48 8b 7c 24 08 48 c7 c6 e0 24 6b 8b 48 8b 14 24 4c 89 f1 4d 89 e0 4c 8b 4c 24 10 41 52 <67> 48 0f b9 3a 48 83 c4 08 e8 48 9b ee 02 e9 66 fd ff ff 48 c7 c1
RSP: 0018:ffffc9000cf4fd80 EFLAGS: 00010246
RAX: ffffffff8b6b23a0 RBX: ffff8880466e5058 RCX: ffff8880466e5058
RDX: 0000000000000000 RSI: ffffffff8b6b24e0 RDI: ffffffff8f858150
RBP: ffff8880466e50b0 R08: 0000000000000000 R09: ffff888000e3a4c0
R10: ffffffff8b6b23a0 R11: ffffed1008cdca0d R12: 0000000000000000
R13: dffffc0000000000 R14: ffff8880466e5058 R15: 1ffff11008cdca0c
FS:  00007f1ebe4c26c0(0000) GS:ffff88808d416000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1ebe4c1fc8 CR3: 0000000010f71000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 inode_unlock include/linux/fs.h:1037 [inline]
 __start_dirop fs/namei.c:2868 [inline]
 start_dirop fs/namei.c:2875 [inline]
 do_rmdir+0x1e6/0x4a0 fs/namei.c:5284
 __do_sys_rmdir fs/namei.c:5315 [inline]
 __se_sys_rmdir fs/namei.c:5313 [inline]
 __x64_sys_rmdir+0x47/0x50 fs/namei.c:5313
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1ebd58f7c9
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:00007f1ebe4c2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 00007f1ebd7e6180 RCX: 00007f1ebd58f7c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000100
RBP: 00007f1ebd613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1ebd7e6218 R14: 00007f1ebd7e6180 R15: 00007fff6895f0e8
 </TASK>
----------------
Code disassembly (best guess):
   0:	6b 8b 49 c7 c2 c0 23 	imul   $0x23,-0x3f3d38b7(%rbx),%ecx
   7:	6b 8b 4c 0f 44 d0 48 	imul   $0x48,-0x2fbbf0b4(%rbx),%ecx
   e:	8b 7c 24 08          	mov    0x8(%rsp),%edi
  12:	48 c7 c6 e0 24 6b 8b 	mov    $0xffffffff8b6b24e0,%rsi
  19:	48 8b 14 24          	mov    (%rsp),%rdx
  1d:	4c 89 f1             	mov    %r14,%rcx
  20:	4d 89 e0             	mov    %r12,%r8
  23:	4c 8b 4c 24 10       	mov    0x10(%rsp),%r9
  28:	41 52                	push   %r10
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 83 c4 08          	add    $0x8,%rsp
  33:	e8 48 9b ee 02       	call   0x2ee9b80
  38:	e9 66 fd ff ff       	jmp    0xfffffda3
  3d:	48                   	rex.W
  3e:	c7                   	.byte 0xc7
  3f:	c1                   	.byte 0xc1

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/31 00:03 upstream dbf8fe85a16a d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in do_rmdir
2025/11/21 01:36 upstream 8e621c9a3375 280ea308 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in do_rmdir
2025/10/22 08:36 upstream 552c50713f27 252fbbad .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in do_rmdir
2025/10/11 00:42 upstream 917167ed1211 ff1712fe .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in do_rmdir
2025/07/12 10:59 upstream 379f604cc3dc 3cda49cf .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in do_rmdir
2025/05/07 10:29 upstream 0d8d44db295c 350f4ffc .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in do_rmdir
2025/04/17 00:29 upstream c62f4b82d571 a95239b1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in do_rmdir
2025/09/13 06:28 linux-next 590b221ed425 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in do_rmdir
2025/06/03 09:03 linux-next a0bea9e39035 b396b4bf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in do_rmdir
2025/06/03 09:03 linux-next a0bea9e39035 b396b4bf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in do_rmdir
* Struck through repros no longer work on HEAD.