syzbot


WARNING in do_loopback

Status: upstream: reported on 2024/02/29 12:54
Reported-by: syzbot+5ac59587cd99810d2319@syzkaller.appspotmail.com
First crash: 116d, last: 41d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in do_loopback 1 59d 59d 0/3 upstream: reported on 2024/04/26 13:38
upstream WARNING in do_loopback fs 1 326d 322d 0/27 auto-obsoleted due to no activity on 2023/11/01 08:13
upstream WARNING in do_loopback (2) fs 10 1d22h 76d 0/27 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 = 0xffff8880550180e0, owner = 0x0, curr 0xffff888061b03b80, list empty
WARNING: CPU: 1 PID: 4710 at kernel/locking/rwsem.c:1372 __up_write kernel/locking/rwsem.c:1371 [inline]
WARNING: CPU: 1 PID: 4710 at kernel/locking/rwsem.c:1372 up_write+0x4f5/0x580 kernel/locking/rwsem.c:1626
Modules linked in:
CPU: 1 PID: 4710 Comm: syz-executor.4 Not tainted 6.1.90-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:__up_write kernel/locking/rwsem.c:1371 [inline]
RIP: 0010:up_write+0x4f5/0x580 kernel/locking/rwsem.c:1626
Code: 48 c7 c7 60 f5 eb 8a 48 c7 c6 a0 f7 eb 8a 48 8b 54 24 28 48 8b 4c 24 18 4d 89 e0 4c 8b 4c 24 30 53 e8 df d7 e8 ff 48 83 c4 08 <0f> 0b e9 71 fd ff ff 48 c7 c1 e8 b6 73 8e 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc90003ebfca0 EFLAGS: 00010296
RAX: d5ea993fefabea00 RBX: ffffffff8aebf640 RCX: 0000000000040000
RDX: ffffc90006189000 RSI: 000000000000b050 RDI: 000000000000b051
RBP: ffffc90003ebfd70 R08: ffffffff81528ede R09: fffff520007d7ef5
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffff8880550180e0 R14: 1ffff920007d7f9c R15: dffffc0000000000
FS:  00007fd40d3f66c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c002f743e4 CR3: 00000000563bd000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 inode_unlock include/linux/fs.h:763 [inline]
 unlock_mount fs/namespace.c:2325 [inline]
 do_loopback+0x4a5/0x510 fs/namespace.c:2459
 do_mount fs/namespace.c:3394 [inline]
 __do_sys_mount fs/namespace.c:3602 [inline]
 __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3579
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd40e87dd69
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:00007fd40d3f60c8 EFLAGS: 00000246
 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd40e9ac050 RCX: 00007fd40e87dd69
RDX: 0000000000000000 RSI: 0000000020000580 RDI: 0000000020000540
RBP: 00007fd40e8ca49e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001080 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fd40e9ac050 R15: 00007fff57ee67b8
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/14 11:25 linux-6.1.y 909ba1f1b414 fdb4c10c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in do_loopback
2024/02/29 12:53 linux-6.1.y 81e1dc2f7001 352ab904 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in do_loopback
* Struck through repros no longer work on HEAD.