kernel BUG in ext4_write_inline_data_end (2)

Status: premoderation: reported syz repro on 2026/06/16 00:15
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+918168c0e26bc69753fb@syzkaller.appspotmail.com
First crash: 59d, last: 1d16h
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2026/07/11 lts (merge base) 4fd016be1e49 syz [report] lost connection to test machine
2026/07/11 upstream (ToT) 59dee6d28756 syz [report] lost connection to test machine
▶ ▼ Similar bugs (15)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel BUG at fs/ext4/inline.c:LINE! ext4 -1 syz, C done done 76 1307d 2130d 22/29 fixed on 2023/02/24 13:50
android-54 kernel BUG in ext4_write_inline_data_end -1 syz, C 4 1491d 1624d 2/2 fixed on 2022/09/27 22:24
android-5-10 kernel BUG in ext4_write_inline_data_end -1 syz, C error 3 1557d 1624d 0/2 closed as dup on 2022/03/04 15:25
android-5-15 kernel BUG in ext4_write_inline_data_end (2) origin:upstream -1 syz, C error 16 27d 1055d 0/2 upstream: reported C repro on 2023/09/24 12:05
android-5-10 kernel BUG in ext4_write_inline_data_end (2) -1 syz, C error 23 54d 1509d 2/2 upstream: reported C repro on 2022/06/27 15:18
linux-6.1 kernel BUG in ext4_write_inline_data_end origin:upstream -1 syz, C error 44 489d 1251d 0/3 upstream: reported C repro on 2023/03/12 18:03
android-6-1 kernel BUG in ext4_write_inline_data_end origin:lts -1 syz, C error done 2 601d 1004d 0/2 auto-obsoleted due to no activity on 2025/03/30 21:55
android-5-15 kernel BUG in ext4_write_inline_data_end -1 syz, C error 11 1348d 1409d 2/2 fixed on 2023/02/02 00:40
linux-4.19 kernel BUG in ext4_write_inline_data_end ext4 -1 syz, C error 12 1260d 2007d 0/1 upstream: reported C repro on 2021/02/14 13:39
upstream kernel BUG in ext4_write_inline_data_end (3) prio:normal ext4 -1 syz 1 16d 29d 0/29 upstream: reported syz repro on 2026/07/16 07:50
linux-5.15 kernel BUG in ext4_write_inline_data_end origin:upstream -1 syz, C error 9 54d 1172d 0/3 upstream: reported C repro on 2023/05/30 10:48
upstream kernel BUG in ext4_write_inline_data_end ext4 -1 syz, C error done 32 963d 1261d 25/29 fixed on 2024/01/30 23:26
android-54 kernel BUG in ext4_write_inline_data_end (2) ext4 -1 syz 9 532d 1297d 0/2 upstream: reported syz repro on 2023/01/25 15:39
linux-4.14 kernel BUG in ext4_write_inline_data_end -1 syz, C error 4 1347d 1932d 0/1 upstream: reported C repro on 2021/04/30 02:18
upstream kernel BUG in ext4_write_inline_data_end (2) ext4 -1 syz, C inconclusive error 174 56d 924d 29/29 fixed on 2026/07/15 08:27
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/07/16 22:57 14m retest repro android14-6.1 log
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2026/07/21 06:55 1h22m bisect fix android14-6.1 OK (0) job log log

Sample crash report:
------------[ cut here ]------------
kernel BUG at fs/ext4/inline.c:785!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 13245 Comm: syz.6.10192 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:ext4_write_inline_data_end+0xa36/0xa40 fs/ext4/inline.c:785
Code: d2 cc ff e9 16 f9 ff ff 44 89 f1 80 e1 07 fe c1 38 c1 0f 8c 09 fb ff ff 4c 89 f7 e8 04 d2 cc ff e9 fc fa ff ff e8 aa 47 87 ff <0f> 0b e8 a3 47 87 ff 0f 0b 90 55 48 89 e5 41 57 41 56 41 55 41 54
RSP: 0018:ffffc900023cf6e0 EFLAGS: 00010293
RAX: ffffffff81ea1e96 RBX: 0000000400080000 RCX: ffff88812f93d100
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900023cf800 R08: ffff88812fdbd067 R09: 1ffff11025fb7a0c
R10: dffffc0000000000 R11: ffffed1025fb7a0d R12: 1ffff92000479ee8
R13: ffff88812fdbd060 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007efc146b56c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efc14693ff8 CR3: 0000000132ed4000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_write_end+0x397/0x930 fs/ext4/inode.c:1349
 ext4_da_write_end+0x8b/0x930 fs/ext4/inode.c:3087
 generic_perform_write+0x3e5/0x740 mm/filemap.c:3926
 ext4_buffered_write_iter+0x38f/0x690 fs/ext4/file.c:285
 ext4_file_write_iter+0x4b2/0x1540 fs/ext4/file.c:-1
 call_write_iter include/linux/fs.h:2282 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x5ef/0xd00 fs/read_write.c:584
 ksys_write+0x14a/0x260 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:646
 x64_sys_call+0x27b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7efc1379e0d9
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:00007efc146b5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007efc13a25fa0 RCX: 00007efc1379e0d9
RDX: 0000000000000023 RSI: 00002000000000c0 RDI: 0000000000000006
RBP: 00007efc13835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efc13a26038 R14: 00007efc13a25fa0 R15: 00007ffed436e478
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_write_inline_data_end+0xa36/0xa40 fs/ext4/inline.c:785
Code: d2 cc ff e9 16 f9 ff ff 44 89 f1 80 e1 07 fe c1 38 c1 0f 8c 09 fb ff ff 4c 89 f7 e8 04 d2 cc ff e9 fc fa ff ff e8 aa 47 87 ff <0f> 0b e8 a3 47 87 ff 0f 0b 90 55 48 89 e5 41 57 41 56 41 55 41 54
RSP: 0018:ffffc900023cf6e0 EFLAGS: 00010293
RAX: ffffffff81ea1e96 RBX: 0000000400080000 RCX: ffff88812f93d100
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900023cf800 R08: ffff88812fdbd067 R09: 1ffff11025fb7a0c
R10: dffffc0000000000 R11: ffffed1025fb7a0d R12: 1ffff92000479ee8
R13: ffff88812fdbd060 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007efc146b56c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc22c70aff8 CR3: 0000000132ed4000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/13 04:08 android14-6.1 92668decd5e0 359b2492 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-android-6-1 kernel BUG in ext4_write_inline_data_end
2026/06/16 00:14 android14-6.1 f17c14b8ada7 50bb0618 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-android-6-1 kernel BUG in ext4_write_inline_data_end
* Struck through repros no longer work on HEAD.