syzbot


WARNING in do_loopback (2)

Status: moderation: reported on 2024/04/09 04:36
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+54b23838c478d1b401a1@syzkaller.appspotmail.com
First crash: 46d, last: 4d08h
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 WARNING in do_loopback 2 7d07h 82d 0/3 upstream: reported on 2024/02/29 12:54
linux-5.15 WARNING in do_loopback 1 25d 25d 0/3 upstream: reported on 2024/04/26 13:38
upstream WARNING in do_loopback fs 1 292d 288d 0/26 auto-obsoleted due to no activity on 2023/11/01 08:13

Sample crash report:
------------[ cut here ]------------
DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff888079c836d0, owner = 0x0, curr 0xffff88802a160000, list empty
WARNING: CPU: 0 PID: 14579 at kernel/locking/rwsem.c:1370 __up_write kernel/locking/rwsem.c:1369 [inline]
WARNING: CPU: 0 PID: 14579 at kernel/locking/rwsem.c:1370 up_write+0x502/0x590 kernel/locking/rwsem.c:1632
Modules linked in:

CPU: 0 PID: 14579 Comm: syz-executor.3 Not tainted 6.9.0-syzkaller-08284-gea5f6ad9ad96 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:__up_write kernel/locking/rwsem.c:1369 [inline]
RIP: 0010:up_write+0x502/0x590 kernel/locking/rwsem.c:1632
Code: c7 c7 40 a9 ca 8b 48 c7 c6 c0 ab ca 8b 48 8b 54 24 28 48 8b 4c 24 18 4d 89 e0 4c 8b 4c 24 30 53 e8 f3 90 e6 ff 48 83 c4 08 90 <0f> 0b 90 90 e9 6a fd ff ff 48 c7 c1 80 0d ad 8f 80 e1 07 80 c1 03
RSP: 0018:ffffc90004937c80 EFLAGS: 00010292
RAX: 1059a2d232d9e000 RBX: ffffffff8bcaaa20 RCX: 0000000000040000
RDX: ffffc9001008a000 RSI: 0000000000014bd9 RDI: 0000000000014bda
RBP: ffffc90004937d50 R08: ffffffff81585642 R09: 1ffffffff1f59b45
R10: dffffc0000000000 R11: fffffbfff1f59b46 R12: 0000000000000000
R13: ffff888079c836d0 R14: 1ffff92000926f98 R15: dffffc0000000000
FS:  00007fb3fd9c86c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001f28c000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 inode_unlock include/linux/fs.h:796 [inline]
 unlock_mount fs/namespace.c:2514 [inline]
 do_loopback+0x4ad/0x520 fs/namespace.c:2648
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb3fcc7cee9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb3fd9c80c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fb3fcdac050 RCX: 00007fb3fcc7cee9
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000020000100
RBP: 00007fb3fccc949e R08: 0000000000000000 R09: 0000000000000000
R10: 00000000001adc51 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fb3fcdac050 R15: 00007ffd512f0388
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/17 10:39 upstream ea5f6ad9ad96 c2e07261 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in do_loopback
2024/05/07 16:32 upstream dccb07f2914c cb2dcc0e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in do_loopback
2024/04/22 08:36 upstream 48cf398f15fc af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in do_loopback
2024/04/05 04:25 upstream fe46a7dd189e 0ee3535e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in do_loopback
2024/04/28 16:30 linux-next bb7a2467e6be 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in do_loopback
* Struck through repros no longer work on HEAD.