linux-kernel - [syzbot] [ocfs2?] kernel BUG in ocfs2_truncate_log_needs

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Message-ID: <68713fad.a00a0220.26a83e.0057.GAE@google.com>
Date: Fri, 11 Jul 2025 09:45:33 -0700
From: syzbot <syzbot+c24237f0eee59c0c2abb@...kaller.appspotmail.com>
To: jlbec@...lplan.org, joseph.qi@...ux.alibaba.com, 
	linux-kernel@...r.kernel.org, mark@...heh.com, ocfs2-devel@...ts.linux.dev, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [ocfs2?] kernel BUG in ocfs2_truncate_log_needs_flush (2)

Hello,

syzbot found the following issue on:

HEAD commit:    8c2e52ebbe88 eventpoll: don't decrement ep refcount while ..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=177cea8c580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b309c907eaab29da
dashboard link: https://syzkaller.appspot.com/bug?extid=c24237f0eee59c0c2abb
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=12e99bd4580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1702c0f0580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-8c2e52eb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fd9c3cb36878/vmlinux-8c2e52eb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0f323b0a9d42/bzImage-8c2e52eb.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/d0ab42c91b28/mount_0.gz
  fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=14e99bd4580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c24237f0eee59c0c2abb@...kaller.appspotmail.com

(syz.0.16,5478,0):ocfs2_truncate_log_needs_flush:5830 ERROR: bug expression: le16_to_cpu(tl->tl_used) > le16_to_cpu(tl->tl_count)
(syz.0.16,5478,0):ocfs2_truncate_log_needs_flush:5830 ERROR: slot 0, invalid truncate log parameters: used = 128, count = 39
------------[ cut here ]------------
kernel BUG at fs/ocfs2/alloc.c:5830!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5478 Comm: syz.0.16 Not tainted 6.16.0-rc5-syzkaller-00053-g8c2e52ebbe88 #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:ocfs2_truncate_log_needs_flush+0x2d8/0x2e0 fs/ocfs2/alloc.c:5827
Code: 0f b7 00 4c 89 e7 48 c7 c6 35 c0 a6 8d ba c6 16 00 00 48 c7 c1 c0 23 ca 8b 45 89 e8 45 89 f9 50 e8 5d 11 1e 00 48 83 c4 08 90 <0f> 0b 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90002c7f540 EFLAGS: 00010292
RAX: c11493c73e537600 RBX: ffff888031704174 RCX: c11493c73e537600
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc90002c7f610 R08: ffffc90002c7f107 R09: 1ffff9200058fe20
R10: dffffc0000000000 R11: fffff5200058fe21 R12: ffffc90002c7f5a0
R13: 0000000000000000 R14: 1ffff11007d6bf58 R15: 0000000000000080
FS:  000055557c057500(0000) GS:ffff88808d21b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001400 CR3: 000000004f209000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 ocfs2_xattr_set+0xaea/0x11f0 fs/ocfs2/xattr.c:3624
 __vfs_setxattr+0x439/0x480 fs/xattr.c:200
 __vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:234
 vfs_setxattr+0x16b/0x2f0 fs/xattr.c:321
 do_setxattr fs/xattr.c:636 [inline]
 filename_setxattr+0x274/0x600 fs/xattr.c:665
 path_setxattrat+0x364/0x3a0 fs/xattr.c:713
 __do_sys_setxattr fs/xattr.c:747 [inline]
 __se_sys_setxattr fs/xattr.c:743 [inline]
 __x64_sys_setxattr+0xbc/0xe0 fs/xattr.c:743
 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: 0033:0x7f0edcd8e929
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:00007ffd28be2a78 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 00007f0edcfb5fa0 RCX: 00007f0edcd8e929
RDX: 0000200000001400 RSI: 0000200000000240 RDI: 00002000000001c0
RBP: 00007f0edce10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000841 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0edcfb5fa0 R14: 00007f0edcfb5fa0 R15: 0000000000000005
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ocfs2_truncate_log_needs_flush+0x2d8/0x2e0 fs/ocfs2/alloc.c:5827
Code: 0f b7 00 4c 89 e7 48 c7 c6 35 c0 a6 8d ba c6 16 00 00 48 c7 c1 c0 23 ca 8b 45 89 e8 45 89 f9 50 e8 5d 11 1e 00 48 83 c4 08 90 <0f> 0b 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90002c7f540 EFLAGS: 00010292
RAX: c11493c73e537600 RBX: ffff888031704174 RCX: c11493c73e537600
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc90002c7f610 R08: ffffc90002c7f107 R09: 1ffff9200058fe20
R10: dffffc0000000000 R11: fffff5200058fe21 R12: ffffc90002c7f5a0
R13: 0000000000000000 R14: 1ffff11007d6bf58 R15: 0000000000000080
FS:  000055557c057500(0000) GS:ffff88808d21b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001400 CR3: 000000004f209000 CR4: 0000000000352ef0


---
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