syzbot


WARNING in unlock_mount (2)

Status: moderation: reported on 2025/07/14 17:10
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+0bc701da7fdb42731cdd@syzkaller.appspotmail.com
First crash: 7d04h, last: 7d04h
Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 WARNING in unlock_mount -1 3 695d 713d 0/3 auto-obsoleted due to no activity on 2023/12/02 19:20
linux-5.15 WARNING in unlock_mount (2) -1 2 294d 309d 0/3 auto-obsoleted due to no activity on 2025/01/06 17:35
upstream WARNING in unlock_mount fs -1 7 327d 468d 0/29 auto-obsoleted due to no activity on 2024/11/25 05:01
linux-5.15 WARNING in unlock_mount -1 2 695d 696d 0/3 auto-obsoleted due to no activity on 2023/12/03 05:00
linux-6.1 WARNING in unlock_mount (2) -1 6 345d 473d 0/3 auto-obsoleted due to no activity on 2024/11/16 19:35
linux-5.15 WARNING in unlock_mount (3) -1 1 109d 109d 0/3 auto-obsoleted due to no activity on 2025/07/11 02:56
linux-6.1 WARNING in unlock_mount (3) -1 2 211d 238d 0/3 auto-obsoleted due to no activity on 2025/03/31 14:44

Sample crash report:
DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff88806786ebd8, owner = 0x0, curr 0xffff8880698f9e00, list empty
WARNING: kernel/locking/rwsem.c:1383 at __up_write kernel/locking/rwsem.c:1382 [inline], CPU#1: syz.4.2052/17445
WARNING: kernel/locking/rwsem.c:1383 at up_write+0x3a2/0x420 kernel/locking/rwsem.c:1645, CPU#1: syz.4.2052/17445
Modules linked in:
CPU: 1 UID: 0 PID: 17445 Comm: syz.4.2052 Not tainted 6.16.0-rc5-next-20250711-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__up_write kernel/locking/rwsem.c:1382 [inline]
RIP: 0010:up_write+0x3a2/0x420 kernel/locking/rwsem.c:1645
Code: d0 48 c7 c7 00 ef 8a 8b 48 c7 c6 20 f1 8a 8b 48 8b 14 24 4c 89 f1 4d 89 e0 4c 8b 4c 24 08 41 52 e8 13 43 e6 ff 48 83 c4 08 90 <0f> 0b 90 90 e9 6d fd ff ff 48 c7 c1 74 ec a3 8f 80 e1 07 80 c1 03
RSP: 0018:ffffc90003b6fc68 EFLAGS: 00010282
RAX: ed36858078f48500 RBX: ffff88806786ebd8 RCX: 0000000000080000
RDX: ffffc9000f5b3000 RSI: 000000000000661a RDI: 000000000000661b
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa4d8 R12: 0000000000000000
R13: ffff88806786ec30 R14: ffff88806786ebd8 R15: 1ffff1100cf0dd7c
FS:  00007fa008f9e6c0(0000) GS:ffff888125cc6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2f94383000 CR3: 0000000078056000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 inode_unlock include/linux/fs.h:879 [inline]
 unlock_mount+0x81/0x360 fs/namespace.c:2846
 do_loopback+0x3b5/0x430 fs/namespace.c:3044
 do_mount fs/namespace.c:4133 [inline]
 __do_sys_mount fs/namespace.c:4344 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4321
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa00818e929
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:00007fa008f9e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fa0083b6160 RCX: 00007fa00818e929
RDX: 0000000000000000 RSI: 0000200000000200 RDI: 0000200000000c40
RBP: 00007fa008210b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000002901090 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fa0083b6160 R15: 00007fff95cb9588
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/13 12:01 linux-next a62b7a37e6fc 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in unlock_mount
* Struck through repros no longer work on HEAD.