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: 1457d, last: 7d12h
Cause bisection: failed (error log, bisect log)
  
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel BUG in ext4_split_extent_at ext4 -1 1 1730d 1726d 0/29 auto-closed as invalid on 2022/06/08 01:32
upstream kernel BUG in ext4_split_extent_at (2) ext4 -1 syz, C error done 3 1045d 1240d 25/29 fixed on 2024/01/30 15:47
android-6-1 kernel BUG in ext4_split_extent_at (3) -1 2 222d 240d 0/2 auto-obsoleted due to no activity on 2026/06/24 18:09
android-6-1 kernel BUG in ext4_split_extent_at missing-backport origin:upstream -1 syz, C error error 1 783d 1244d 0/2 auto-obsoleted due to no activity on 2024/12/21 09:12
android-6-1 kernel BUG in ext4_split_extent_at (2) origin:lts -1 syz, C done 1 477d 477d 0/2 auto-obsoleted due to no activity on 2025/10/22 23:15
upstream kernel BUG in ext4_split_extent_at (3) ext4 -1 3 480d 496d 0/29 auto-obsoleted due to no activity on 2025/10/19 20:03
linux-6.1 kernel BUG in ext4_split_extent_at -1 syz, C error 3 222d 238d 0/3 auto-obsoleted due to no activity on 2026/09/22 21:28
android-5-15 kernel BUG in ext4_split_extent_at missing-backport origin:lts -1 syz, C error error 12 95d 524d 0/2 upstream: reported C repro on 2025/05/29 02:28
▶ ▼ Last patch testing requests (10)
Created Duration User Patch Repo Result
2026/10/28 01:47 16m retest repro android13-5.10-lts report job log log
2026/10/28 01:47 18m retest repro android13-5.10-lts no crash job log log
2026/10/28 01:47 22m retest repro android13-5.10-lts no crash job log log
2026/10/28 01:47 18m retest repro android13-5.10-lts no crash job log log
2026/10/28 01:47 16m retest repro android13-5.10-lts no crash job log log
2026/08/23 09:34 19m retest repro android13-5.10-lts report job log log
2026/08/23 09:34 18m retest repro android13-5.10-lts report job log log
2026/06/29 22:41 12m retest repro android13-5.10-lts log
2026/06/29 22:41 1h33m retest repro android13-5.10-lts log
2026/06/29 22:41 1h26m retest repro android13-5.10-lts log

Sample crash report:
------------[ cut here ]------------
kernel BUG at fs/ext4/extents.c:3180!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 306 Comm: syz-executor319 Not tainted 5.10.234-syzkaller-00148-g6686f2996d23 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:ext4_split_extent_at+0x121c/0x1240 fs/ext4/extents.c:3180
Code: fe c1 38 c1 0f 8c 16 fa ff ff e8 cf b7 cf ff 48 8b 54 24 58 48 8b 74 24 40 e9 02 fa ff ff e8 1b 18 92 ff 0f 0b e8 14 18 92 ff <0f> 0b e8 0d 18 92 ff 0f 0b e8 d6 49 d5 02 e8 01 18 92 ff 0f 0b e8
RSP: 0018:ffffc90000be7820 EFLAGS: 00010293
RAX: ffffffff81d8a74c RBX: 0000000000000000 RCX: ffff88810d6d2780
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000be7990 R08: ffffffff81d897b2 R09: ffffc90000be7920
R10: fffff5200017cf25 R11: dffffc0000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff11021cc2919 R15: 0000000000000000
FS:  00007fbc565b06c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000400000076000 CR3: 000000010ef7a000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ext4_force_split_extent_at fs/ext4/extents.c:318 [inline]
 ext4_ext_remove_space+0x719/0x4e10 fs/ext4/extents.c:2873
 ext4_punch_hole+0x720/0xb10 fs/ext4/inode.c:4216
 ext4_fallocate+0x2e8/0x1cc0 fs/ext4/extents.c:4756
 vfs_fallocate+0x492/0x570 fs/open.c:310
 ksys_fallocate fs/open.c:333 [inline]
 __do_sys_fallocate fs/open.c:341 [inline]
 __se_sys_fallocate fs/open.c:339 [inline]
 __x64_sys_fallocate+0xc0/0x110 fs/open.c:339
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fbc56625ed9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 1f 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbc565b0168 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007fbc566a8738 RCX: 00007fbc56625ed9
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000004
RBP: 00007fbc566a8730 R08: 00007fbc565b06c0 R09: 0000000000000000
R10: 0000000000001a00 R11: 0000000000000246 R12: 00007fbc566a873c
R13: 000000000000006e R14: 00007fff78c06810 R15: 00007fff78c068f8
Modules linked in:
---[ end trace 94e63d4c12775fb0 ]---
RIP: 0010:ext4_split_extent_at+0x121c/0x1240 fs/ext4/extents.c:3180
Code: fe c1 38 c1 0f 8c 16 fa ff ff e8 cf b7 cf ff 48 8b 54 24 58 48 8b 74 24 40 e9 02 fa ff ff e8 1b 18 92 ff 0f 0b e8 14 18 92 ff <0f> 0b e8 0d 18 92 ff 0f 0b e8 d6 49 d5 02 e8 01 18 92 ff 0f 0b e8
RSP: 0018:ffffc90000be7820 EFLAGS: 00010293
RAX: ffffffff81d8a74c RBX: 0000000000000000 RCX: ffff88810d6d2780
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000be7990 R08: ffffffff81d897b2 R09: ffffc90000be7920
R10: fffff5200017cf25 R11: dffffc0000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff11021cc2919 R15: 0000000000000000
FS:  00007fbc565b06c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbc566726e8 CR3: 000000010ef7a000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (25):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/12 08:04 android13-5.10-lts 6686f2996d23 f2baddf5 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-android-5-10 kernel BUG in ext4_split_extent_at
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
2026/03/11 09:39 android13-5.10-lts 9136079e403a 86914af9 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2026/03/05 08:28 android13-5.10-lts dad37bbb13a8 a9fe5c9e .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2026/01/06 12:32 android13-5.10-lts e253c52bbdfc d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2025/12/19 23:59 android13-5.10-lts e253c52bbdfc d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2025/02/12 06:47 android13-5.10-lts 6686f2996d23 f2baddf5 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] 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
2026/05/10 03:40 android13-5.10-lts 5feb5545d40a 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2026/05/06 08:28 android13-5.10-lts b06f61e488ca 26da2c66 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2026/05/06 08:28 android13-5.10-lts b06f61e488ca 26da2c66 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2026/05/02 11:02 android13-5.10-lts 7ae299a5827a a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2026/03/11 10:54 android13-5.10-lts 9136079e403a 86914af9 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2026/03/11 10:17 android13-5.10-lts 9136079e403a 86914af9 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2026/03/09 23:59 android13-5.10-lts 9136079e403a 176bead5 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2026/03/06 05:15 android13-5.10-lts dad37bbb13a8 31e9c887 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2026/03/05 17:07 android13-5.10-lts dad37bbb13a8 d20b04c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2026/01/07 04:12 android13-5.10-lts e253c52bbdfc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2025/12/19 01:24 android13-5.10-lts e253c52bbdfc d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (corrupt fs)] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2025/06/22 17:06 android13-5.10-lts d76d4cd0623a d6cdfb8a .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2025/05/29 13:35 android13-5.10-lts cf6ed0f1511d 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2025/04/02 00:26 android13-5.10-lts 094fc3778d6b b8645499 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (corrupt fs)] ci2-android-5-10 kernel BUG in ext4_split_extent_at
2025/02/27 03:27 android13-5.10-lts 3f5f2283d684 6a8fcbc4 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] 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.