syzbot


kernel BUG in ext4_split_extent_at

Status: upstream: reported C repro on 2023/06/09 00:07
Reported-by: syzbot+1257631df4d42447d768@syzkaller.appspotmail.com
First crash: 622d, last: 59d
Cause bisection: failed (error log, bisect log)
  
Fix bisection: failed (error log, bisect log)
  
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel BUG in ext4_split_extent_at ext4 1 895d 891d 0/27 auto-closed as invalid on 2022/06/08 01:32
upstream kernel BUG in ext4_split_extent_at (2) ext4 C error done 3 210d 405d 26/27 fixed on 2024/01/30 15:47
android-6-1 kernel BUG in ext4_split_extent_at origin:upstream missing-backport C error 1 23d 409d 0/2 upstream: reported C repro on 2023/06/09 05:14
android-5-15 kernel BUG in ext4_split_extent_at origin:upstream missing-backport syz error 1 38d 409d 0/2 premoderation: reported syz repro on 2023/06/09 01:17
Last patch testing requests (10)
Created Duration User Patch Repo Result
2024/05/24 08:15 19m retest repro android13-5.10-lts report log
2024/05/24 08:15 7m retest repro android13-5.10-lts report log
2024/03/15 07:35 13m retest repro android13-5.10-lts report log
2024/03/15 07:35 5m retest repro android13-5.10-lts report log
2024/01/05 02:08 13m retest repro android13-5.10-lts report log
2024/01/05 01:45 6m retest repro android13-5.10-lts report log
2023/10/27 01:56 10m retest repro android13-5.10-lts report log
2023/10/27 01:33 5m retest repro android13-5.10-lts report log
2023/08/18 01:32 24m retest repro android13-5.10-lts report log
2023/08/18 00:04 46m retest repro android13-5.10-lts report log

Sample crash report:
------------[ cut here ]------------
kernel BUG at fs/ext4/ext4_extents.h:199!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 1064 Comm: syz-executor276 Not tainted 5.10.178-syzkaller-00127-g43c801dc3325 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
RIP: 0010:ext4_ext_mark_unwritten fs/ext4/ext4_extents.h:199 [inline]
RIP: 0010:ext4_split_extent_at+0x10f0/0x1100 fs/ext4/extents.c:3216
Code: fb cf ff 48 8b 74 24 68 48 8b 54 24 40 e9 46 fa ff ff e8 d3 ed 92 ff 0f 0b e8 cc ed 92 ff 0f 0b e8 75 34 d2 02 e8 c0 ed 92 ff <0f> 0b e8 b9 ed 92 ff 0f 0b e8 b2 ed 92 ff 0f 0b 55 48 89 e5 41 57
RSP: 0018:ffffc90001c66e60 EFLAGS: 00010293
RAX: ffffffff81d78560 RBX: 0000000000000000 RCX: ffff88811e424f00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90001c66fd8 R08: ffffffff81d77915 R09: ffffed10238a0e7f
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888119b8a200
R13: ffff88811b9de010 R14: 0000000000000000 R15: 0000000000000004
FS:  00007f891a7d2700(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002003f000 CR3: 000000010e1c5000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ext4_split_extent+0x370/0x4e0 fs/ext4/extents.c:3380
 ext4_split_convert_extents fs/ext4/extents.c:3708 [inline]
 ext4_ext_handle_unwritten_extents fs/ext4/extents.c:3870 [inline]
 ext4_ext_map_blocks+0x210f/0x6be0 fs/ext4/extents.c:4162
 ext4_map_blocks+0xaa7/0x1f00 fs/ext4/inode.c:646
 ext4_iomap_alloc fs/ext4/inode.c:3516 [inline]
 ext4_iomap_begin+0x798/0xbb0 fs/ext4/inode.c:3566
 iomap_apply+0x116/0x8a0 fs/iomap/apply.c:46
 __iomap_dio_rw+0x767/0x10f0 fs/iomap/direct-io.c:525
 iomap_dio_rw+0x35/0x80 fs/iomap/direct-io.c:613
 ext4_dio_write_iter fs/ext4/file.c:577 [inline]
 ext4_file_write_iter+0x10e8/0x1ca0 fs/ext4/file.c:687
 call_write_iter include/linux/fs.h:1976 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0xb55/0xe70 fs/read_write.c:605
 ksys_write+0x199/0x2c0 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:667
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xc6
RIP: 0033:0x7f8922c0fbf9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 18 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f891a7d2208 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000027 RCX: 00007f8922c0fbf9
RDX: 0000000000000012 RSI: 0000000020000000 RDI: 0000000000000004
RBP: 00007f8922c8d790 R08: 00007f8922c8d798 R09: 00007f8922c8d798
R10: 00007f8922c8d798 R11: 0000000000000246 R12: 00007f8922c8d79c
R13: 00007ffd4671edef R14: 00007f891a7d2300 R15: 0000000000022000
Modules linked in:
---[ end trace d5301ebced837581 ]---
RIP: 0010:ext4_ext_mark_unwritten fs/ext4/ext4_extents.h:199 [inline]
RIP: 0010:ext4_split_extent_at+0x10f0/0x1100 fs/ext4/extents.c:3216
Code: fb cf ff 48 8b 74 24 68 48 8b 54 24 40 e9 46 fa ff ff e8 d3 ed 92 ff 0f 0b e8 cc ed 92 ff 0f 0b e8 75 34 d2 02 e8 c0 ed 92 ff <0f> 0b e8 b9 ed 92 ff 0f 0b e8 b2 ed 92 ff 0f 0b 55 48 89 e5 41 57
RSP: 0018:ffffc90001c66e60 EFLAGS: 00010293
RAX: ffffffff81d78560 RBX: 0000000000000000 RCX: ffff88811e424f00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90001c66fd8 R08: ffffffff81d77915 R09: ffffed10238a0e7f
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888119b8a200
R13: ffff88811b9de010 R14: 0000000000000000 R15: 0000000000000004
FS:  00007f891a7d2700(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8922c4b3b0 CR3: 000000010e1c5000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/06/09 00:04 android13-5.10-lts 43c801dc3325 058b3a5a .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2022/12/14 02:28 android12-5.10-lts 202ee063496e f6511626 .config strace log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2023/06/08 22:36 android13-5.10-lts 43c801dc3325 058b3a5a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2022/11/08 00:29 android12-5.10-lts 0118fb827bc7 6feb842b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_split_extent_at
* Struck through repros no longer work on HEAD.