syzbot


WARNING in do_loopback

Status: upstream: reported on 2024/04/26 13:38
Reported-by: syzbot+c8e81ac628b184c8302c@syzkaller.appspotmail.com
First crash: 48d, last: 48d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 WARNING in do_loopback 2 30d 105d 0/3 upstream: reported on 2024/02/29 12:54
upstream WARNING in do_loopback fs 1 315d 311d 0/28 auto-obsoleted due to no activity on 2023/11/01 08:13
upstream WARNING in do_loopback (2) fs 9 3d14h 65d 0/28 moderation: reported on 2024/04/09 04:36

Sample crash report:
DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff888070fcaf70, owner = 0x0, curr 0xffff8880216dbb80, list empty
WARNING: CPU: 1 PID: 4937 at kernel/locking/rwsem.c:1350 __up_write kernel/locking/rwsem.c:1349 [inline]
WARNING: CPU: 1 PID: 4937 at kernel/locking/rwsem.c:1350 up_write+0x4f5/0x580 kernel/locking/rwsem.c:1604
Modules linked in:
CPU: 1 PID: 4937 Comm: syz-executor.3 Not tainted 5.15.156-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:__up_write kernel/locking/rwsem.c:1349 [inline]
RIP: 0010:up_write+0x4f5/0x580 kernel/locking/rwsem.c:1604
Code: 48 c7 c7 00 1d 8b 8a 48 c7 c6 c0 1f 8b 8a 48 8b 54 24 28 48 8b 4c 24 18 4d 89 e0 4c 8b 4c 24 30 53 e8 df 0d ea ff 48 83 c4 08 <0f> 0b e9 71 fd ff ff 48 c7 c1 88 8e e4 8d 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc900034ffca0 EFLAGS: 00010296
RAX: ebc39c168a63a700 RBX: ffffffff8a8b1de0 RCX: 0000000000040000
RDX: ffffc9000beca000 RSI: 000000000000b5fb RDI: 000000000000b5fc
RBP: ffffc900034ffd70 R08: ffffffff8166862c R09: ffffed10173667a8
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffff888070fcaf70 R14: 1ffff9200069ff9c R15: dffffc0000000000
FS:  00007fe080a666c0(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2664217e00 CR3: 0000000059df2000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 inode_unlock include/linux/fs.h:794 [inline]
 unlock_mount fs/namespace.c:2281 [inline]
 do_loopback+0x4a5/0x510 fs/namespace.c:2415
 do_mount fs/namespace.c:3348 [inline]
 __do_sys_mount fs/namespace.c:3556 [inline]
 __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3533
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe082514ea9
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:00007fe080a660c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe082643050 RCX: 00007fe082514ea9
RDX: 0000000000000000 RSI: 0000000020000200 RDI: 00000000200002c0
RBP: 00007fe0825614a4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000101091 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fe082643050 R15: 00007fff37db9848
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/26 13:37 linux-5.15.y c52b9710c83d 059e9963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in do_loopback
* Struck through repros no longer work on HEAD.