syzbot


kernel BUG in ocfs2_reserve_suballoc_bits

Status: upstream: reported on 2025/09/15 10:29
Reported-by: syzbot+5a15d22dc46712e41ffc@syzkaller.appspotmail.com
First crash: 7h02m, last: 7h02m
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 kernel BUG in ocfs2_reserve_suballoc_bits -1 1 182d 182d 0/3 auto-obsoleted due to no activity on 2025/06/25 12:34
linux-6.1 kernel BUG in ocfs2_reserve_suballoc_bits (2) -1 1 7d05h 7d05h 0/3 upstream: reported on 2025/09/08 12:17
upstream kernel BUG in ocfs2_reserve_suballoc_bits ocfs2 -1 C 344 5d01h 317d 0/29 upstream: reported C repro on 2024/11/01 20:51

Sample crash report:
------------[ cut here ]------------
kernel BUG at fs/ocfs2/suballoc.c:800!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 4395 Comm: syz.2.20 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:ocfs2_reserve_suballoc_bits+0x3c3f/0x4350 fs/ocfs2/suballoc.c:800
Code: 00 00 e9 27 f3 ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 4b df ff ff 4c 89 f7 e8 3b a1 9a fe e9 3e df ff ff e8 c1 38 56 fe <0f> 0b 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c e6 e0 ff ff 4c 89 e7
RSP: 0018:ffffc9000457e5e0 EFLAGS: 00010283
RAX: ffffffff8321925f RBX: ffff88805a4e9e00 RCX: 0000000000080000
RDX: ffffc9000ef2c000 RSI: 000000000000a6f0 RDI: 000000000000a6f1
RBP: ffffc9000457eab0 R08: dffffc0000000000 R09: fffffbfff1ad323e
R10: fffffbfff1ad323e R11: 1ffffffff1ad323d R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88805e85cfb8 R15: 0000000000000001
FS:  00007f1baf4766c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f23ff9ab000 CR3: 0000000073fc2000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ocfs2_reserve_cluster_bitmap_bits+0xc1/0x1c0 fs/ocfs2/suballoc.c:1128
 ocfs2_local_alloc_reserve_for_window fs/ocfs2/localalloc.c:1112 [inline]
 ocfs2_local_alloc_slide_window fs/ocfs2/localalloc.c:1248 [inline]
 ocfs2_reserve_local_alloc_bits+0x876/0x24c0 fs/ocfs2/localalloc.c:668
 ocfs2_reserve_clusters_with_limit+0x1bb/0xba0 fs/ocfs2/suballoc.c:1162
 ocfs2_reserve_clusters fs/ocfs2/suballoc.c:1223 [inline]
 ocfs2_lock_allocators+0x2f7/0x5b0 fs/ocfs2/suballoc.c:2669
 ocfs2_write_begin_nolock+0x2216/0x4180 fs/ocfs2/aops.c:1741
 ocfs2_write_begin+0x1ab/0x300 fs/ocfs2/aops.c:1905
 generic_perform_write+0x2aa/0x530 mm/filemap.c:3785
 __generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912
 ocfs2_file_write_iter+0x1578/0x1cf0 fs/ocfs2/file.c:2472
 call_write_iter include/linux/fs.h:2172 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x712/0xd00 fs/read_write.c:594
 ksys_pwrite64 fs/read_write.c:701 [inline]
 __do_sys_pwrite64 fs/read_write.c:711 [inline]
 __se_sys_pwrite64 fs/read_write.c:708 [inline]
 __x64_sys_pwrite64+0x194/0x220 fs/read_write.c:708
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f1bb122fba9
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:00007f1baf476038 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f1bb1477090 RCX: 00007f1bb122fba9
RDX: 00000000200000c1 RSI: 00002000000000c0 RDI: 0000000000000006
RBP: 00007f1bb12b2e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000009000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1bb1477128 R14: 00007f1bb1477090 R15: 00007ffd494aa678
 </TASK>
Modules linked in:
---[ end trace 7be98a5f92d22f44 ]---
RIP: 0010:ocfs2_reserve_suballoc_bits+0x3c3f/0x4350 fs/ocfs2/suballoc.c:800
Code: 00 00 e9 27 f3 ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 4b df ff ff 4c 89 f7 e8 3b a1 9a fe e9 3e df ff ff e8 c1 38 56 fe <0f> 0b 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c e6 e0 ff ff 4c 89 e7
RSP: 0018:ffffc9000457e5e0 EFLAGS: 00010283
RAX: ffffffff8321925f RBX: ffff88805a4e9e00 RCX: 0000000000080000
RDX: ffffc9000ef2c000 RSI: 000000000000a6f0 RDI: 000000000000a6f1
RBP: ffffc9000457eab0 R08: dffffc0000000000 R09: fffffbfff1ad323e
R10: fffffbfff1ad323e R11: 1ffffffff1ad323d R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88805e85cfb8 R15: 0000000000000001
FS:  00007f1baf4766c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffeb1f5ddf8 CR3: 0000000073fc2000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/15 10:29 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ocfs2_reserve_suballoc_bits
* Struck through repros no longer work on HEAD.