syzbot


WARNING in chmod_common (3)

Status: moderation: reported on 2025/07/05 23:20
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+0f4421321ddbe8f9d4b3@syzkaller.appspotmail.com
First crash: 59d, last: 23d
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in chmod_common (2) fs -1 1 141d 137d 0/29 auto-obsoleted due to no activity on 2025/06/09 21:36
linux-6.1 WARNING in chmod_common -1 1 465d 465d 0/3 auto-obsoleted due to no activity on 2024/08/29 23:15
linux-6.1 WARNING in chmod_common (2) origin:upstream missing-backport -1 C inconclusive 2 84d 147d 0/3 upstream: reported C repro on 2025/04/04 16:09
upstream WARNING in chmod_common fs -1 9 258d 506d 0/29 auto-obsoleted due to no activity on 2025/03/15 12:07

Sample crash report:
loop0: detected capacity change from 0 to 32768
gfs2: fsid=syz:syz: Trying to join cluster "lock_nolock", "syz:syz"
gfs2: fsid=syz:syz: Now mounting FS (format 1801)...
gfs2: fsid=syz:syz.0: journal 0 mapped with 1 extents in 0ms
gfs2: fsid=syz:syz.0: first mount done, others may mount
------------[ cut here ]------------
DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff8880440794e8, owner = 0x0, curr 0xffff8880336da440, list empty
WARNING: CPU: 0 PID: 5357 at kernel/locking/rwsem.c:1381 __up_write kernel/locking/rwsem.c:1380 [inline]
WARNING: CPU: 0 PID: 5357 at kernel/locking/rwsem.c:1381 up_write+0x3a2/0x420 kernel/locking/rwsem.c:1643
Modules linked in:
CPU: 0 UID: 0 PID: 5357 Comm: syz.0.0 Not tainted 6.16.0-syzkaller-11852-g479058002c32 #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+0x3a2/0x420 kernel/locking/rwsem.c:1643
Code: d0 48 c7 c7 a0 ec 8a 8b 48 c7 c6 c0 ee 8a 8b 48 8b 14 24 4c 89 f1 4d 89 e0 4c 8b 4c 24 08 41 52 e8 d3 56 e6 ff 48 83 c4 08 90 <0f> 0b 90 90 e9 6d fd ff ff 48 c7 c1 74 93 a3 8f 80 e1 07 80 c1 03
RSP: 0018:ffffc9000fc4fc50 EFLAGS: 00010296
RAX: e730238941c5a400 RBX: ffff8880440794e8 RCX: ffff8880336da440
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa1ec R12: 0000000000000000
R13: ffff888044079540 R14: ffff8880440794e8 R15: 1ffff1100880f29e
FS:  00007f24923796c0(0000) GS:ffff88808d218000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2492336fc8 CR3: 00000000119ec000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 inode_unlock include/linux/fs.h:879 [inline]
 chmod_common+0x253/0x400 fs/open.c:653
 do_fchmodat+0x12d/0x200 fs/open.c:697
 __do_sys_fchmodat fs/open.c:716 [inline]
 __se_sys_fchmodat fs/open.c:713 [inline]
 __x64_sys_fchmodat+0x7d/0x90 fs/open.c:713
 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: 0033:0x7f249158ebe9
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:00007f2492379038 EFLAGS: 00000246 ORIG_RAX: 000000000000010c
RAX: ffffffffffffffda RBX: 00007f24917b5fa0 RCX: 00007f249158ebe9
RDX: 00000000fffffed3 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f2491611e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f24917b6038 R14: 00007f24917b5fa0 R15: 00007ffcfe2482b8
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/06 14:59 upstream 479058002c32 4bd24a3e .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in chmod_common
2025/07/01 23:17 upstream 66701750d556 a073c096 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in chmod_common
* Struck through repros no longer work on HEAD.