[syzbot] [gfs2?] kernel BUG in gfs2_withdraw (2)

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syzbot

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Aug 17, 2025, 1:58:39 PM8/17/25
to agru...@redhat.com, gf...@lists.linux.dev, linux-...@vger.kernel.org, syzkall...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: 8742b2d8935f Merge tag 'pull-fixes' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1414cda2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=d67d3af29f50297e
dashboard link: https://syzkaller.appspot.com/bug?extid=901524eae72170197041
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-8742b2d8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b561d09cce5a/vmlinux-8742b2d8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0eac1e9113b1/bzImage-8742b2d8.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+901524...@syzkaller.appspotmail.com

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 5 extents in 0ms
gfs2: fsid=syz:syz.0: first mount done, others may mount
gfs2: fsid=syz:syz.0: fatal: invalid metadata block - bh = 2051 (type: exp=14, found=8), function = gfs2_quota_init, file = fs/gfs2/quota.c, line = 1430
gfs2: fsid=syz:syz.0: about to withdraw this file system
------------[ cut here ]------------
kernel BUG at fs/gfs2/util.c:331!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5364 Comm: syz.0.0 Not tainted 6.17.0-rc1-syzkaller-00016-g8742b2d8935f #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:gfs2_withdraw+0x137b/0x1430 fs/gfs2/util.c:331
Code: ff ff 48 8b 4c 24 18 80 e1 07 80 c1 03 38 c1 0f 8c 55 fb ff ff 48 8b 7c 24 18 e8 20 7c 25 fe e9 46 fb ff ff e8 86 90 c0 fd 90 <0f> 0b 48 8b 4c 24 18 80 e1 07 80 c1 03 38 c1 0f 8c ab fb ff ff 48
RSP: 0018:ffffc9000d32f680 EFLAGS: 00010293
RAX: ffffffff83ff2ada RBX: ffffc9000d32f740 RCX: ffff888000aa0000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000000
RBP: ffffc9000d32f810 R08: ffff88801fc24253 R09: 1ffff11003f8484a
R10: dffffc0000000000 R11: ffffed1003f8484b R12: dffffc0000000000
R13: 1ffff92001a65ee4 R14: 1ffff110087b3815 R15: 0000000000000004
FS: 00007fc82060a6c0(0000) GS:ffff88808d211000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdc3a1909c0 CR3: 0000000042f3e000 CR4: 0000000000352ef0
Call Trace:
<TASK>
gfs2_metatype_check_ii+0x78/0x90 fs/gfs2/util.c:514
gfs2_metatype_check_i fs/gfs2/util.h:129 [inline]
gfs2_quota_init+0xfc8/0x1230 fs/gfs2/quota.c:1430
gfs2_make_fs_rw+0x181/0x2b0 fs/gfs2/super.c:149
gfs2_fill_super+0x1a7b/0x20d0 fs/gfs2/ops_fstype.c:1278
get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692
gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1335
vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
do_new_mount+0x2a2/0x9e0 fs/namespace.c:3805
do_mount fs/namespace.c:4133 [inline]
__do_sys_mount fs/namespace.c:4344 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4321
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: 0033:0x7fc81f79038a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007fc820609e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fc820609ef0 RCX: 00007fc81f79038a
RDX: 0000200000000400 RSI: 0000200000012500 RDI: 00007fc820609eb0
RBP: 0000200000000400 R08: 00007fc820609ef0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000012500
R13: 00007fc820609eb0 R14: 00000000000125bb R15: 0000200000000900
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:gfs2_withdraw+0x137b/0x1430 fs/gfs2/util.c:331
Code: ff ff 48 8b 4c 24 18 80 e1 07 80 c1 03 38 c1 0f 8c 55 fb ff ff 48 8b 7c 24 18 e8 20 7c 25 fe e9 46 fb ff ff e8 86 90 c0 fd 90 <0f> 0b 48 8b 4c 24 18 80 e1 07 80 c1 03 38 c1 0f 8c ab fb ff ff 48
RSP: 0018:ffffc9000d32f680 EFLAGS: 00010293
RAX: ffffffff83ff2ada RBX: ffffc9000d32f740 RCX: ffff888000aa0000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000000
RBP: ffffc9000d32f810 R08: ffff88801fc24253 R09: 1ffff11003f8484a
R10: dffffc0000000000 R11: ffffed1003f8484b R12: dffffc0000000000
R13: 1ffff92001a65ee4 R14: 1ffff110087b3815 R15: 0000000000000004
FS: 00007fc82060a6c0(0000) GS:ffff88808d211000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdc3a1909c0 CR3: 0000000042f3e000 CR4: 0000000000352ef0


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

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If the report is already addressed, let syzbot know by replying with:
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If you want to overwrite report's subsystems, reply with:
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If the report is a duplicate of another one, reply with:
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If you want to undo deduplication, reply with:
#syz undup

Andrew Price

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Aug 18, 2025, 8:44:07 AM8/18/25
to syzbot, agru...@redhat.com, gf...@lists.linux.dev, linux-...@vger.kernel.org, syzkall...@googlegroups.com
That's strange, this should have been prevented by this syzbot fix:

https://github.com/google/syzkaller/commit/338f25e2408a360bd3af7f03091b1cbda0887a52

Perhaps it hasn't gone live yet?

Andy

syzbot

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Aug 26, 2025, 1:27:33 AM8/26/25
to agru...@redhat.com, anp...@redhat.com, gf...@lists.linux.dev, linux-...@vger.kernel.org, syzkall...@googlegroups.com
syzbot has found a reproducer for the following issue on:

HEAD commit: b6add54ba618 Merge tag 'pinctrl-v6.17-2' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=174cf862580000
kernel config: https://syzkaller.appspot.com/x/.config?x=a7016efe6aaa498c
dashboard link: https://syzkaller.appspot.com/bug?extid=901524eae72170197041
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12dc8634580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16dc8634580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-b6add54b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a6e94bac86a3/vmlinux-b6add54b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0c9cbb4d239d/bzImage-b6add54b.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/df6a4ddf7d5b/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=13dcc462580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+901524...@syzkaller.appspotmail.com

gfs2: fsid=syz:syz.s: fatal: invalid metadata block - bh = 19 (type: exp=4, found=1), function = gfs2_meta_buffer, file = fs/gfs2/meta_io.c, line = 499
gfs2: fsid=syz:syz.s: about to withdraw this file system
------------[ cut here ]------------
kernel BUG at fs/gfs2/util.c:331!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5528 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:gfs2_withdraw+0x137b/0x1430 fs/gfs2/util.c:331
Code: ff ff 48 8b 4c 24 18 80 e1 07 80 c1 03 38 c1 0f 8c 55 fb ff ff 48 8b 7c 24 18 e8 90 56 25 fe e9 46 fb ff ff e8 06 6a c0 fd 90 <0f> 0b 48 8b 4c 24 18 80 e1 07 80 c1 03 38 c1 0f 8c ab fb ff ff 48
RSP: 0018:ffffc90002bff2a0 EFLAGS: 00010293
RAX: ffffffff83ff513a RBX: ffffc90002bff360 RCX: ffff8880003f2440
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000000
RBP: ffffc90002bff430 R08: ffff88801fc24253 R09: 1ffff11003f8484a
R10: dffffc0000000000 R11: ffffed1003f8484b R12: dffffc0000000000
R13: 1ffff9200057fe68 R14: 1ffff110066ba015 R15: 0000000000000004
FS: 0000555589e6b500(0000) GS:ffff88808d210000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa802461000 CR3: 00000000346f0000 CR4: 0000000000352ef0
Call Trace:
<TASK>
gfs2_metatype_check_ii+0x78/0x90 fs/gfs2/util.c:514
gfs2_metatype_check_i fs/gfs2/util.h:129 [inline]
gfs2_meta_buffer+0x25e/0x300 fs/gfs2/meta_io.c:499
gfs2_meta_inode_buffer fs/gfs2/meta_io.h:70 [inline]
gfs2_inode_refresh fs/gfs2/glops.c:484 [inline]
inode_go_instantiate+0xdf/0x1260 fs/gfs2/glops.c:509
gfs2_instantiate+0x165/0x220 fs/gfs2/glock.c:468
gfs2_glock_holder_ready fs/gfs2/glock.c:1332 [inline]
gfs2_glock_wait+0x1d4/0x2a0 fs/gfs2/glock.c:1352
gfs2_glock_nq_init fs/gfs2/glock.h:248 [inline]
check_journal_clean+0x11c/0x310 fs/gfs2/util.c:61
init_journal+0x17f8/0x2260 fs/gfs2/ops_fstype.c:793
init_inodes+0xdb/0x320 fs/gfs2/ops_fstype.c:851
gfs2_fill_super+0x1923/0x20d0 fs/gfs2/ops_fstype.c:1253
get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1692
gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1335
vfs_get_tree+0x92/0x2b0 fs/super.c:1815
do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
do_mount fs/namespace.c:4136 [inline]
__do_sys_mount fs/namespace.c:4347 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4324
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: 0033:0x7fbbb439038a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007ffccc5a4b98 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffccc5a4c20 RCX: 00007fbbb439038a
RDX: 0000200000000400 RSI: 0000200000012500 RDI: 00007ffccc5a4be0
RBP: 0000200000000400 R08: 00007ffccc5a4c20 R09: 0000000000200000
R10: 0000000000200000 R11: 0000000000000246 R12: 0000200000012500
R13: 00007ffccc5a4be0 R14: 00000000000125bb R15: 0000200000000f40
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:gfs2_withdraw+0x137b/0x1430 fs/gfs2/util.c:331
Code: ff ff 48 8b 4c 24 18 80 e1 07 80 c1 03 38 c1 0f 8c 55 fb ff ff 48 8b 7c 24 18 e8 90 56 25 fe e9 46 fb ff ff e8 06 6a c0 fd 90 <0f> 0b 48 8b 4c 24 18 80 e1 07 80 c1 03 38 c1 0f 8c ab fb ff ff 48
RSP: 0018:ffffc90002bff2a0 EFLAGS: 00010293
RAX: ffffffff83ff513a RBX: ffffc90002bff360 RCX: ffff8880003f2440
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000000
RBP: ffffc90002bff430 R08: ffff88801fc24253 R09: 1ffff11003f8484a
R10: dffffc0000000000 R11: ffffed1003f8484b R12: dffffc0000000000
R13: 1ffff9200057fe68 R14: 1ffff110066ba015 R15: 0000000000000004
FS: 0000555589e6b500(0000) GS:ffff88808d210000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc5ba20d000 CR3: 00000000346f0000 CR4: 0000000000352ef0


---
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syzbot

unread,
Feb 27, 2026, 7:40:16 AM (20 hours ago) Feb 27
to syzkall...@googlegroups.com
Auto-closing this bug as obsolete.
No recent activity, existing reproducers are no longer triggering the issue.
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