syzbot


kernel BUG in ext4_write_inline_data (4)

Status: upstream: reported syz repro on 2026/02/02 18:16
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+7de5fe447862fc37576f@syzkaller.appspotmail.com
First crash: 5d00h, last: 4d07h
Cause bisection: failed (error log, bisect log)
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ext4?] kernel BUG in ext4_write_inline_data (4) 0 (5) 2026/02/03 14:30
Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 kernel BUG in ext4_write_inline_data ext4 -1 C 4 1093d 1189d 0/1 upstream: reported C repro on 2022/11/04 18:44
upstream kernel BUG at fs/ext4/inline.c:LINE! ext4 -1 C done done 76 1117d 1940d 22/29 fixed on 2023/02/24 13:50
upstream kernel BUG in ext4_write_inline_data ext4 -1 C error 36 571d 1057d 27/29 fixed on 2024/08/22 01:52
linux-6.1 kernel BUG in ext4_write_inline_data origin:upstream -1 C error 11 225d 332d 0/3 upstream: reported C repro on 2025/03/10 13:01
android-6-1 kernel BUG in ext4_write_inline_data origin:lts -1 C error error 26 19d 949d 0/2 upstream: reported C repro on 2023/07/02 21:30
upstream kernel BUG in ext4_write_inline_data (3) ext4 -1 C error 8 36d 145d 29/29 fixed on 2026/01/07 12:29
linux-4.19 kernel BUG in ext4_write_inline_data_end ext4 -1 C error 12 1070d 1817d 0/1 upstream: reported C repro on 2021/02/14 13:39
upstream kernel BUG in ext4_write_inline_data (2) ext4 -1 C error 46 227d 441d 29/29 fixed on 2025/07/08 00:33
android-5-10 kernel BUG in ext4_write_inline_data ext4 -1 C error inconclusive 3 1089d 1187d 2/2 fixed on 2023/05/04 14:51
android-54 kernel BUG in ext4_write_inline_data -1 C 3 1150d 1187d 2/2 fixed on 2023/04/05 17:17
Last patch testing requests (4)
Created Duration User Patch Repo Result
2026/02/03 14:30 23m kartikey406@gmail.com patch upstream report log
2026/02/03 07:52 27m kartikey406@gmail.com patch upstream error
2026/02/03 06:41 50m kartikey406@gmail.com patch upstream error
2026/02/03 05:17 1h16m kartikey406@gmail.com patch upstream error

Sample crash report:
------------[ cut here ]------------
kernel BUG at fs/ext4/inline.c:240!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 6836 Comm: syz.5.137 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:ext4_write_inline_data+0x40b/0x4f0 fs/ext4/inline.c:240
Code: fe e8 e9 70 3f ff 42 8d 44 23 c4 bb 3c 00 00 00 89 44 24 08 44 29 e3 e9 aa fe ff ff e8 ce 70 3f ff 90 0f 0b e8 c6 70 3f ff 90 <0f> 0b e8 be 70 3f ff 48 8d 3d b7 58 f6 0d 48 c7 c2 60 5b ac 8b 4c
RSP: 0018:ffffc9000b0b74e0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000001000 RCX: ffffffff82c7675b
RDX: ffff88802c845b80 RSI: ffffffff82c7697a RDI: ffff88802c845b80
RBP: ffff888075742918 R08: 0000000000000006 R09: 0000000000004000
R10: 000000000000003c R11: 0000000000000000 R12: 0000000000003000
R13: 0000000000004000 R14: ffffc9000b0b7580 R15: ffff888075742e82
FS:  00007fb1c0b036c0(0000) GS:ffff8881245dc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f284e6ff000 CR3: 000000005cb37000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 ext4_write_inline_data_end+0x2a8/0xdb0 fs/ext4/inline.c:817
 ext4_da_write_end+0x4f7/0xf20 fs/ext4/inode.c:3286
 generic_perform_write+0x513/0xa40 mm/filemap.c:4335
 ext4_buffered_write_iter+0x119/0x440 fs/ext4/file.c:299
 ext4_file_write_iter+0xa3d/0x1d90 fs/ext4/file.c:723
 iter_file_splice_write+0x82b/0x10a0 fs/splice.c:738
 do_splice_from fs/splice.c:938 [inline]
 direct_splice_actor+0x192/0x6c0 fs/splice.c:1161
 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1105
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0x174/0x240 fs/splice.c:1230
 do_sendfile+0xadc/0xe20 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64 fs/read_write.c:1417 [inline]
 __x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1417
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb1bfb9aeb9
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:00007fb1c0b03028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fb1bfe15fa0 RCX: 00007fb1bfb9aeb9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000004
RBP: 00007fb1bfc08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 000000000e3aa6ea R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb1bfe16038 R14: 00007fb1bfe15fa0 R15: 00007ffc03931cf8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_write_inline_data+0x40b/0x4f0 fs/ext4/inline.c:240
Code: fe e8 e9 70 3f ff 42 8d 44 23 c4 bb 3c 00 00 00 89 44 24 08 44 29 e3 e9 aa fe ff ff e8 ce 70 3f ff 90 0f 0b e8 c6 70 3f ff 90 <0f> 0b e8 be 70 3f ff 48 8d 3d b7 58 f6 0d 48 c7 c2 60 5b ac 8b 4c
RSP: 0018:ffffc9000b0b74e0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000001000 RCX: ffffffff82c7675b
RDX: ffff88802c845b80 RSI: ffffffff82c7697a RDI: ffff88802c845b80
RBP: ffff888075742918 R08: 0000000000000006 R09: 0000000000004000
R10: 000000000000003c R11: 0000000000000000 R12: 0000000000003000
R13: 0000000000004000 R14: ffffc9000b0b7580 R15: ffff888075742e82
FS:  00007fb1c0b036c0(0000) GS:ffff8881246dc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efdf1812000 CR3: 000000005cb37000 CR4: 0000000000350ef0

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/01 22:19 upstream 162b42445b58 6b8752f2 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-kasan-badwrites-root kernel BUG in ext4_write_inline_data
2026/02/01 21:23 upstream 162b42445b58 6b8752f2 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-kasan-badwrites-root kernel BUG in ext4_write_inline_data
2026/02/01 06:10 upstream ad9a728a3388 35764559 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root kernel BUG in ext4_write_inline_data
* Struck through repros no longer work on HEAD.