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: 417d, last: 1d03h
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 (656):
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
2026/08/07 03:01 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/08/04 07:40 linux-6.6.y aa0e49877a2e 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/08/04 06:30 linux-6.6.y aa0e49877a2e 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/08/03 19:46 linux-6.6.y aa0e49877a2e 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/08/02 02:41 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/31 03:11 linux-6.6.y a1153c0deb44 aaffb173 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/31 02:11 linux-6.6.y a1153c0deb44 aaffb173 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/29 10:36 linux-6.6.y c5596480c50e 19622d9d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/28 23:49 linux-6.6.y c5596480c50e edc8a875 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/26 15:15 linux-6.6.y c5596480c50e 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/26 06:26 linux-6.6.y c5596480c50e 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/25 15:41 linux-6.6.y c5596480c50e 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/24 23:12 linux-6.6.y da47cbc25466 dd737a83 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/24 11:30 linux-6.6.y da47cbc25466 544adce9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/23 20:43 linux-6.6.y da47cbc25466 71a13572 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/23 19:28 linux-6.6.y da47cbc25466 71a13572 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/22 22:31 linux-6.6.y da47cbc25466 4a865b71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/21 18:50 linux-6.6.y da47cbc25466 7c5de9c3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/19 23:13 linux-6.6.y da47cbc25466 72524a66 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/19 12:04 linux-6.6.y da47cbc25466 72524a66 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/18 20:51 linux-6.6.y da47cbc25466 72524a66 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/18 14:17 linux-6.6.y da47cbc25466 72524a66 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/15 03:59 linux-6.6.y da47cbc25466 2130f682 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/14 11:58 linux-6.6.y da47cbc25466 2130f682 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/14 11:49 linux-6.6.y da47cbc25466 2130f682 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/14 08:02 linux-6.6.y da47cbc25466 2130f682 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/09 06:19 linux-6.6.y da47cbc25466 b9f1ceaa .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/07 07:51 linux-6.6.y da47cbc25466 8e71ce95 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/04 06:35 linux-6.6.y d1cfde2d5d15 fcece630 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/03 12:47 linux-6.6.y d1cfde2d5d15 58bf2096 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/07/02 23:30 linux-6.6.y d1cfde2d5d15 2b70b115 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/06/29 20:05 linux-6.6.y d1cfde2d5d15 6a0c72dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/06/28 15:42 linux-6.6.y d1cfde2d5d15 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/06/24 18:43 linux-6.6.y d1cfde2d5d15 302586aa .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/06/24 09:08 linux-6.6.y d1cfde2d5d15 042555ff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/06/20 13:48 linux-6.6.y d1cfde2d5d15 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/06/19 06:22 linux-6.6.y 924b4a879cbb a776b0d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/06/19 00:20 linux-6.6.y 924b4a879cbb a776b0d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/06/18 19:09 linux-6.6.y 924b4a879cbb a776b0d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/06/16 19:56 linux-6.6.y 924b4a879cbb a3998659 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/06/15 23:05 linux-6.6.y 924b4a879cbb 50bb0618 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/06/15 10:37 linux-6.6.y 924b4a879cbb 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/06/15 01:58 linux-6.6.y 924b4a879cbb 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/06/14 21:19 linux-6.6.y 924b4a879cbb 1d2f3589 .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.