syzbot


kernel BUG in f2fs_allocate_data_block

Status: upstream: reported C repro on 2025/06/16 20:16
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+fd1280572f6ac45a8a80@syzkaller.appspotmail.com
First crash: 321d, last: 19h15m
Bug presence (2)
Date Name Commit Repro Result
2025/06/22 linux-6.6.y (ToT) 6282921b6825 C [report] kernel BUG in f2fs_allocate_data_block
2025/06/22 upstream (ToT) 739a6c93cc75 C Didn't crash
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2025/09/15 11:56 1h48m fix candidate upstream OK (0) job log

Sample crash report:
loop0: detected capacity change from 0 to 40427
F2FS-fs (loop0): invalid crc value
F2FS-fs (loop0): Found nat_bits in checkpoint
F2FS-fs (loop0): Start checkpoint disabled!
F2FS-fs (loop0): Mounted with checkpoint version = 48b305e6
------------[ cut here ]------------
kernel BUG at fs/f2fs/segment.c:3481!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 5915 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:f2fs_allocate_data_block+0x3f6f/0x3fb0 fs/f2fs/segment.c:3481
Code: 19 fe 48 8b 54 24 30 e9 88 eb ff ff e8 1a 79 c1 fd 48 c7 c7 90 f6 6f 8d 4c 89 f6 e8 9b a4 97 00 e9 a4 eb ff ff e8 01 79 c1 fd <0f> 0b e8 fa 78 c1 fd 0f 0b e8 f3 78 c1 fd 0f 0b e8 ec 78 c1 fd 0f
RSP: 0018:ffffc90003207410 EFLAGS: 00010293
RAX: ffffffff83c5a8ff RBX: 0000000000000201 RCX: ffff8880249c5a00
RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000200
RBP: 0000000000000200 R08: ffff8880253d585f R09: 1ffff11004a7ab0b
R10: dffffc0000000000 R11: ffffed1004a7ab0c R12: 1ffff92000640ef8
R13: 0000000000000000 R14: 0000000000002a01 R15: dffffc0000000000
FS:  000055556bfd1500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33f63fff CR3: 00000000765cd000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 __allocate_data_block fs/f2fs/data.c:1427 [inline]
 f2fs_map_blocks+0x1338/0x3e60 fs/f2fs/data.c:1610
 f2fs_expand_inode_data+0x67a/0xa10 fs/f2fs/file.c:1851
 f2fs_fallocate+0x416/0x890 fs/f2fs/file.c:1954
 vfs_fallocate+0x58e/0x700 fs/open.c:324
 ioctl_preallocate fs/ioctl.c:291 [inline]
 file_ioctl fs/ioctl.c:331 [inline]
 do_vfs_ioctl+0x19f6/0x1cc0 fs/ioctl.c:850
 __do_sys_ioctl fs/ioctl.c:869 [inline]
 __se_sys_ioctl+0x83/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0ca8b9cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffed6b11278 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0ca8e15fa0 RCX: 00007f0ca8b9cdd9
RDX: 00002000000000c0 RSI: 0000000040305828 RDI: 0000000000000004
RBP: 00007f0ca8c32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0ca8e15fac R14: 00007f0ca8e15fa0 R15: 00007f0ca8e15fa0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:f2fs_allocate_data_block+0x3f6f/0x3fb0 fs/f2fs/segment.c:3481
Code: 19 fe 48 8b 54 24 30 e9 88 eb ff ff e8 1a 79 c1 fd 48 c7 c7 90 f6 6f 8d 4c 89 f6 e8 9b a4 97 00 e9 a4 eb ff ff e8 01 79 c1 fd <0f> 0b e8 fa 78 c1 fd 0f 0b e8 f3 78 c1 fd 0f 0b e8 ec 78 c1 fd 0f
RSP: 0018:ffffc90003207410 EFLAGS: 00010293
RAX: ffffffff83c5a8ff RBX: 0000000000000201 RCX: ffff8880249c5a00
RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000200
RBP: 0000000000000200 R08: ffff8880253d585f R09: 1ffff11004a7ab0b
R10: dffffc0000000000 R11: ffffed1004a7ab0c R12: 1ffff92000640ef8
R13: 0000000000000000 R14: 0000000000002a01 R15: dffffc0000000000
FS:  000055556bfd1500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33f63fff CR3: 00000000765cd000 CR4: 00000000003506f0

Crashes (483):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/26 09:39 linux-6.6.y 9760bf04666d 9c2d0995 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/01/15 01:30 linux-6.6.y c596736dadab d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/09/30 07:24 linux-6.6.y 147338df3487 86341da6 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/06/20 09:27 linux-6.6.y 6282921b6825 ed3e87f7 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/05/03 17:56 linux-6.6.y 258cf62a6dfd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/05/03 17:55 linux-6.6.y 258cf62a6dfd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/27 00:24 linux-6.6.y 9760bf04666d 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/26 09:01 linux-6.6.y 9760bf04666d 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/24 08:42 linux-6.6.y 9760bf04666d 9cfb3ca7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/23 06:09 linux-6.6.y 9760bf04666d b10da5ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/22 17:50 linux-6.6.y 9760bf04666d 4595e353 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/21 13:44 linux-6.6.y 9760bf04666d 3f2e655b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/20 23:40 linux-6.6.y 9760bf04666d e65da4ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/19 22:41 linux-6.6.y 9760bf04666d 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/19 22:40 linux-6.6.y 9760bf04666d 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/19 12:45 linux-6.6.y 9760bf04666d 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/18 22:20 linux-6.6.y 9760bf04666d 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/18 17:37 linux-6.6.y 9760bf04666d 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/17 21:40 linux-6.6.y 8cee53b8eaeb 24ecfc1e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/15 20:39 linux-6.6.y 8cee53b8eaeb c441f497 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/15 10:31 linux-6.6.y 8cee53b8eaeb e2e976a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/15 09:01 linux-6.6.y 8cee53b8eaeb e2e976a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/13 21:13 linux-6.6.y 8cee53b8eaeb 9530ccf9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/09 14:41 linux-6.6.y 80de0a958133 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/08 12:49 linux-6.6.y 80de0a958133 2c961e87 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/08 09:45 linux-6.6.y 80de0a958133 2c961e87 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/08 09:39 linux-6.6.y 80de0a958133 2c961e87 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/06 08:06 linux-6.6.y c09fbcd31ae6 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/05 00:16 linux-6.6.y c09fbcd31ae6 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/03 17:02 linux-6.6.y c09fbcd31ae6 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/03 08:18 linux-6.6.y c09fbcd31ae6 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/01 19:26 linux-6.6.y c09fbcd31ae6 9a1f7828 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/01 19:26 linux-6.6.y c09fbcd31ae6 9a1f7828 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/01 07:06 linux-6.6.y c09fbcd31ae6 fb8b2c26 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/04/01 05:51 linux-6.6.y c09fbcd31ae6 fb8b2c26 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/03/30 16:28 linux-6.6.y c09fbcd31ae6 dcaebc52 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/03/29 22:40 linux-6.6.y c09fbcd31ae6 b5ceaad2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/03/29 21:29 linux-6.6.y c09fbcd31ae6 b5ceaad2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/03/28 21:01 linux-6.6.y c09fbcd31ae6 b5ceaad2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/03/27 20:57 linux-6.6.y c09fbcd31ae6 74a13a23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/03/27 04:58 linux-6.6.y c09fbcd31ae6 766b6434 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/03/27 04:56 linux-6.6.y c09fbcd31ae6 766b6434 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/03/26 03:26 linux-6.6.y c09fbcd31ae6 c6143aac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/03/23 02:58 linux-6.6.y 4fc00fe35d46 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/03/12 20:30 linux-6.6.y 4fc00fe35d46 4efadf07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/03/12 19:21 linux-6.6.y 4fc00fe35d46 4efadf07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/06/16 20:16 linux-6.6.y c2603c511feb d1716036 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
* Struck through repros no longer work on HEAD.