kernel BUG in ext4_write_inline_data_end (3)

Status: upstream: reported syz repro on 2026/07/16 07:50
Subsystems: ext4
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+293a57918b36cfae3d48@syzkaller.appspotmail.com
First crash: 23d, last: 8d20h
▶ ▼ ✨ AI Jobs (4)
ID Workflow Result Correct Bug Created Started Finished Revision
f1331dcc assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ kernel BUG in ext4_write_inline_data_end (3) 2026/07/24 00:02 2026/07/24 00:02 2026/07/24 00:49 71a13572
320e919a assessment-security 💥 kernel BUG in ext4_write_inline_data_end (3) 2026/07/20 00:01 2026/07/20 00:01 2026/07/20 00:21 72524a66
c1575a18 assessment-security 💥 kernel BUG in ext4_write_inline_data_end (3) 2026/07/17 00:40 2026/07/17 00:40 2026/07/17 00:55 49f47391
5e797a08 assessment-security 💥 kernel BUG in ext4_write_inline_data_end (3) 2026/07/15 15:28 2026/07/15 15:28 2026/07/15 15:43 10d97020
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[PATCH] ext4: defend against inline-to-block conversion race in write completion 2 (2) 2026/07/23 12:52
[syzbot] [ext4?] kernel BUG in ext4_write_inline_data_end (3) 0 (6) 2026/07/18 02:05
▶ ▼ 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 1299d 2123d 22/29 fixed on 2023/02/24 13:50
android-54 kernel BUG in ext4_write_inline_data_end -1 syz, C 4 1483d 1617d 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 1550d 1617d 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 20d 1048d 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 47d 1502d 2/2 upstream: reported C repro on 2022/06/27 15:18
android-6-1 kernel BUG in ext4_write_inline_data_end (2) origin:upstream -1 syz 1 17d 52d 0/2 premoderation: reported syz repro on 2026/06/16 00:15
linux-6.1 kernel BUG in ext4_write_inline_data_end origin:upstream -1 syz, C error 44 482d 1243d 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 594d 997d 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 1341d 1402d 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 1253d 2000d 0/1 upstream: reported C repro on 2021/02/14 13:39
linux-5.15 kernel BUG in ext4_write_inline_data_end origin:upstream -1 syz, C error 9 47d 1165d 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 956d 1253d 25/29 fixed on 2024/01/30 23:26
android-54 kernel BUG in ext4_write_inline_data_end (2) ext4 -1 syz 9 525d 1289d 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 1339d 1925d 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 48d 917d 29/29 fixed on 2026/07/15 08:27
▶ ▼ Last patch testing requests (6)
Created Duration User Patch Repo Result
2026/07/29 18:45 23m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2026/07/18 02:05 27m kartikey406@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log
2026/07/17 13:41 38m kartikey406@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2026/07/17 10:53 33m kartikey406@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2026/07/17 09:15 34m kartikey406@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2026/07/17 00:08 2h36m kartikey406@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log

Sample crash report:
------------[ cut here ]------------
kernel BUG at fs/ext4/inline.c:815!
Internal error: Oops - BUG: 00000000f2000800 [#1]  SMP
Modules linked in:
CPU: 1 UID: 0 PID: 20668 Comm: syz.0.3283 Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/02/2026
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : ext4_write_inline_data_end+0x8fc/0x9d8 fs/ext4/ext4.h:3790
lr : ext4_has_inline_data fs/ext4/ext4.h:3790 [inline]
lr : ext4_write_inline_data_end+0x8fc/0x9d8 fs/ext4/inline.c:815
sp : ffff800090e575c0
x29: ffff800090e57670 x28: dfff800000000000 x27: ffff7000121caebc
x26: 0000000000000000 x25: ffff0000e01554b0 x24: fffffdffc3c2a340
x23: ffff800090e575e0 x22: 0000000000000023 x21: 0000000600080000
x20: ffff0000e01556a0 x19: 0000000000000023 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 00000000200000c0
x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000000
x11: 0000000000000000 x10: ffff60001c02aa97 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff8000810066e8
x2 : 0000000000000000 x1 : ffff0000c4c28000 x0 : 0000000000000000
Call trace:
 ext4_has_inline_data fs/ext4/ext4.h:3790 [inline] (P)
 ext4_write_inline_data_end+0x8fc/0x9d8 fs/ext4/inline.c:815 (P)
 ext4_write_end+0x320/0x9e0 fs/ext4/inode.c:1455
 ext4_da_write_end+0x90/0xba0 fs/ext4/inode.c:3297
 generic_perform_write+0x504/0x7a4 mm/filemap.c:4379
 ext4_buffered_write_iter+0xd0/0x2ec fs/ext4/file.c:316
 ext4_file_write_iter+0x1dc/0x134c fs/ext4/file.c:-1
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x51c/0xa0c fs/read_write.c:687
 ksys_write+0x12c/0x228 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:747
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594
Code: c8097f28 35ffffa9 17fffe38 97d939e6 (d4210000) 
---[ end trace 0000000000000000 ]---

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/15 15:13 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci a13c140cc289 209f0369 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci-upstream-gce-arm64 kernel BUG in ext4_write_inline_data_end
* Struck through repros no longer work on HEAD.