syzbot


WARNING in rgblk_free (2)

Status: upstream: reported C repro on 2026/01/12 15:49
Subsystems: gfs2
[Documentation on labels]
Reported-by: syzbot+3e2c95229d1ab81a0bfd@syzkaller.appspotmail.com
First crash: 4d06h, last: 4d04h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [gfs2?] WARNING in rgblk_free (2) 1 (3) 2026/01/12 19:34
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in rgblk_free gfs2 -1 1 491d 491d 0/29 auto-obsoleted due to no activity on 2024/12/21 06:47
Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/01/12 19:12 20m anprice@redhat.com patch upstream OK log

Sample crash report:
gfs2: fsid=syz:syz.0: first mount done, others may mount
gfs2: fsid=syz:syz.0: found 1 quota changes
------------[ cut here ]------------
WARNING: fs/gfs2/rgrp.c:2267 at rgblk_free+0x136/0x750 fs/gfs2/rgrp.c:2267, CPU#0: syz.0.17/5483
Modules linked in:
CPU: 0 UID: 0 PID: 5483 Comm: syz.0.17 Not tainted syzkaller #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:rgblk_free+0x136/0x750 fs/gfs2/rgrp.c:2267
Code: c0 0f 85 fe 05 00 00 45 8b 36 44 89 f7 44 89 e6 e8 cf 42 b9 fd 45 39 e6 76 2e e8 05 41 b9 fd e9 89 00 00 00 e8 fb 40 b9 fd 90 <0f> 0b 65 48 8b 05 b0 f9 78 0e 48 3b 84 24 80 00 00 00 0f 85 a0 05
RSP: 0018:ffffc90002797a80 EFLAGS: 00010293
RAX: ffffffff8407c5a6 RBX: ffff88801fce7000 RCX: ffff888000634980
RDX: 0000000000000000 RSI: 0000000000000927 RDI: 0000000025540013
RBP: ffff88801fce7000 R08: ffffffff8f824677 R09: 1ffffffff1f048ce
R10: dffffc0000000000 R11: fffffbfff1f048cf R12: 0000000000000927
R13: 0000000000000001 R14: 0000000025540013 R15: dffffc0000000000
FS:  000055556242d500(0000) GS:ffff88808d414000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000011b5f000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 gfs2_unlink_di+0x296/0x420 fs/gfs2/rgrp.c:2566
 gfs2_unlink_inode+0x11d/0x180 fs/gfs2/inode.c:1226
 gfs2_unlink+0x448/0x550 fs/gfs2/inode.c:1298
 vfs_rmdir+0x512/0x660 fs/namei.c:5236
 do_rmdir+0x27f/0x4a0 fs/namei.c:5291
 __do_sys_rmdir fs/namei.c:5315 [inline]
 __se_sys_rmdir fs/namei.c:5313 [inline]
 __x64_sys_rmdir+0x47/0x50 fs/namei.c:5313
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbfb358f7c9
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:00007ffc4142d868 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 00007fbfb37e5fa0 RCX: 00007fbfb358f7c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000100
RBP: 00007fbfb3613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbfb37e5fa0 R14: 00007fbfb37e5fa0 R15: 0000000000000001
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/12 14:26 upstream 54e82e93ca93 d1b870e1 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-snapshot-upstream-root WARNING in rgblk_free
2026/01/12 13:31 upstream 54e82e93ca93 d1b870e1 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-snapshot-upstream-root WARNING in rgblk_free
2026/01/12 12:38 upstream 54e82e93ca93 d1b870e1 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-snapshot-upstream-root WARNING in rgblk_free
2026/01/12 11:37 upstream 54e82e93ca93 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in rgblk_free
* Struck through repros no longer work on HEAD.