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: 243d, last: 10h21m
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:
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: 1 PID: 5926 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:f2fs_allocate_data_block+0x3f78/0x3fc0 fs/f2fs/segment.c:3481
Code: 20 fe 48 8b 54 24 30 e9 88 eb ff ff e8 b1 5b c9 fd 48 c7 c7 10 c4 2f 8d 4c 89 f6 e8 22 fb 95 00 e9 a4 eb ff ff e8 98 5b c9 fd <0f> 0b e8 91 5b c9 fd 0f 0b e8 8a 5b c9 fd 0f 0b e8 83 5b c9 fd 0f
RSP: 0018:ffffc900033e7410 EFLAGS: 00010293
RAX: ffffffff83bc4f68 RBX: 0000000000000200 RCX: ffff88802aac8000
RDX: 0000000000000000 RSI: 0000000000000200 RDI: 0000000000000200
RBP: 0000000000000200 R08: ffff888024eb045f R09: 1ffff110049d608b
R10: dffffc0000000000 R11: ffffed10049d608c R12: 1ffff9200067cef8
R13: 0000000000000000 R14: 0000000000001a00 R15: dffffc0000000000
FS:  000055555a35a500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34263fff CR3: 000000002c279000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 __allocate_data_block fs/f2fs/data.c:1421 [inline]
 f2fs_map_blocks+0x12dd/0x3da0 fs/f2fs/data.c:1604
 f2fs_expand_inode_data+0x65e/0xa10 fs/f2fs/file.c:1851
 f2fs_fallocate+0x416/0x8a0 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:-1 [inline]
 do_vfs_ioctl+0x1935/0x1bb0 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+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f25b8d8f749
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:00007ffd508f7438 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f25b8fe5fa0 RCX: 00007f25b8d8f749
RDX: 00002000000000c0 RSI: 0000000040305828 RDI: 0000000000000004
RBP: 00007f25b8e13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f25b8fe5fa0 R14: 00007f25b8fe5fa0 R15: 0000000000000003
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:f2fs_allocate_data_block+0x3f78/0x3fc0 fs/f2fs/segment.c:3481
Code: 20 fe 48 8b 54 24 30 e9 88 eb ff ff e8 b1 5b c9 fd 48 c7 c7 10 c4 2f 8d 4c 89 f6 e8 22 fb 95 00 e9 a4 eb ff ff e8 98 5b c9 fd <0f> 0b e8 91 5b c9 fd 0f 0b e8 8a 5b c9 fd 0f 0b e8 83 5b c9 fd 0f
RSP: 0018:ffffc900033e7410 EFLAGS: 00010293
RAX: ffffffff83bc4f68 RBX: 0000000000000200 RCX: ffff88802aac8000
RDX: 0000000000000000 RSI: 0000000000000200 RDI: 0000000000000200
RBP: 0000000000000200 R08: ffff888024eb045f R09: 1ffff110049d608b
R10: dffffc0000000000 R11: ffffed10049d608c R12: 1ffff9200067cef8
R13: 0000000000000000 R14: 0000000000001a00 R15: dffffc0000000000
FS:  000055555a35a500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb174558000 CR3: 000000002c279000 CR4: 00000000003506f0

Crashes (323):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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
2026/02/15 03:12 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/02/15 02:32 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/02/14 01:55 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/02/12 23:22 linux-6.6.y 1b4ef5214f17 504cb1bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/02/11 07:35 linux-6.6.y c56aaf1a85ae 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/02/10 20:04 linux-6.6.y c56aaf1a85ae 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/02/10 10:38 linux-6.6.y c56aaf1a85ae 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/02/09 18:26 linux-6.6.y c56aaf1a85ae df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/02/09 09:45 linux-6.6.y c56aaf1a85ae 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/02/09 09:44 linux-6.6.y c56aaf1a85ae 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/02/07 10:40 linux-6.6.y c56aaf1a85ae f20fc9f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/02/04 21:26 linux-6.6.y 2cf6f68313dc ea10c935 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/02/04 04:54 linux-6.6.y 2cf6f68313dc 42b01fab .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/02/03 18:28 linux-6.6.y 2cf6f68313dc 6df4c87a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/01/15 00:31 linux-6.6.y c596736dadab d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2026/01/06 18:14 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/12/24 11:03 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/12/23 20:51 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/12/02 09:32 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/11/29 10:33 linux-6.6.y 1e89a1be4fe9 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/11/08 15:57 linux-6.6.y 0a805b6ea8cd 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/11/04 05:46 linux-6.6.y 0a805b6ea8cd 686bf657 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/11/01 08:37 linux-6.6.y e5bbb12db2c7 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/11/01 08:37 linux-6.6.y e5bbb12db2c7 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/10/31 19:54 linux-6.6.y e5bbb12db2c7 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/10/26 23:24 linux-6.6.y 4a243110dc88 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/10/25 17:40 linux-6.6.y 4a243110dc88 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/10/23 09:20 linux-6.6.y f231f248323d c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/10/22 17:42 linux-6.6.y f231f248323d 252fbbad .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/10/21 17:26 linux-6.6.y f231f248323d 9832ed61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/10/04 07:03 linux-6.6.y f34f16e5c632 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/10/02 23:31 linux-6.6.y f34f16e5c632 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/10/01 04:28 linux-6.6.y 147338df3487 65a0eece .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/09/30 06:21 linux-6.6.y 147338df3487 86341da6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/09/25 20:19 linux-6.6.y 147338df3487 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/09/25 03:26 linux-6.6.y af1544b5d072 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/09/24 23:28 linux-6.6.y af1544b5d072 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/09/23 00:24 linux-6.6.y af1544b5d072 0ac7291c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/09/22 23:18 linux-6.6.y af1544b5d072 0ac7291c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/09/22 03:57 linux-6.6.y af1544b5d072 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/09/22 02:38 linux-6.6.y af1544b5d072 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in f2fs_allocate_data_block
2025/09/21 09:25 linux-6.6.y af1544b5d072 67c37560 .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.