syzbot


kernel BUG in ext4_write_inline_data (4)

Status: upstream: reported C repro on 2026/02/02 18:16
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+7de5fe447862fc37576f@syzkaller.appspotmail.com
First crash: 16d, last: 1d06h
Cause bisection: failed (error log, bisect log)
  
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] ext4: convert inline data to extents when truncate exceeds inline size 3 (3) 2026/02/12 01:14
[syzbot] [ext4?] kernel BUG in ext4_write_inline_data (4) 0 (8) 2026/02/11 11:30
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 1105d 1201d 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 1129d 1952d 22/29 fixed on 2023/02/24 13:50
upstream kernel BUG in ext4_write_inline_data ext4 -1 C error 36 583d 1068d 27/29 fixed on 2024/08/22 01:52
linux-6.1 kernel BUG in ext4_write_inline_data origin:upstream -1 C error 13 6d15h 344d 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 27 10d 960d 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 48d 157d 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 1082d 1829d 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 239d 453d 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 1101d 1199d 2/2 fixed on 2023/05/04 14:51
android-54 kernel BUG in ext4_write_inline_data -1 C 3 1161d 1199d 2/2 fixed on 2023/04/05 17:17
Last patch testing requests (6)
Created Duration User Patch Repo Result
2026/02/07 00:39 2h48m kartikey406@gmail.com patch upstream OK log
2026/02/06 13:10 33m kartikey406@gmail.com patch upstream report log
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: 6183 Comm: syz.1.27 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+0x43c/0x440 fs/ext4/inline.c:240
Code: c1 38 c1 0f 8c 19 ff ff ff 48 89 df 49 89 d7 e8 3a 5d ac ff 4c 89 fa e9 06 ff ff ff e8 7d 31 43 ff 90 0f 0b e8 75 31 43 ff 90 <0f> 0b 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f
RSP: 0018:ffffc900041bf3a8 EFLAGS: 00010293
RAX: ffffffff8281434b RBX: 0000000000003000 RCX: ffff88802ab8dac0
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000003000
RBP: ffff888072ee11a2 R08: ffff88805b996387 R09: 1ffff1100b732c70
R10: dffffc0000000000 R11: ffffed100b732c71 R12: 000000000000003c
R13: ffffc900041bf460 R14: 0000000000002000 R15: ffff888072ee0c38
FS:  00007f67e2ffe6c0(0000) GS:ffff8881256ca000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555753c59e8 CR3: 0000000079001000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 ext4_write_inline_data_end+0x34d/0xad0 fs/ext4/inline.c:817
 generic_perform_write+0x620/0x8f0 mm/filemap.c:4335
 ext4_buffered_write_iter+0xce/0x3a0 fs/ext4/file.c:300
 ext4_file_write_iter+0x298/0x1c10 fs/ext4/file.c:-1
 iter_file_splice_write+0x99b/0x1100 fs/splice.c:738
 do_splice_from fs/splice.c:938 [inline]
 direct_splice_actor+0x101/0x160 fs/splice.c:1161
 splice_direct_to_actor+0x53a/0xc70 fs/splice.c:1105
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0x195/0x290 fs/splice.c:1230
 do_sendfile+0x535/0x7d0 fs/read_write.c:1372
 __do_sys_sendfile64 fs/read_write.c:1433 [inline]
 __se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1419
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f67e399bf79
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:00007f67e2ffe028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f67e3c15fa0 RCX: 00007f67e399bf79
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000004
RBP: 00007f67e3a327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000e3aa6ea R11: 0000000000000246 R12: 0000000000000000
R13: 00007f67e3c16038 R14: 00007f67e3c15fa0 R15: 00007fff789394f8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_write_inline_data+0x43c/0x440 fs/ext4/inline.c:240
Code: c1 38 c1 0f 8c 19 ff ff ff 48 89 df 49 89 d7 e8 3a 5d ac ff 4c 89 fa e9 06 ff ff ff e8 7d 31 43 ff 90 0f 0b e8 75 31 43 ff 90 <0f> 0b 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f
RSP: 0018:ffffc900041bf3a8 EFLAGS: 00010293

RAX: ffffffff8281434b RBX: 0000000000003000 RCX: ffff88802ab8dac0
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000003000
RBP: ffff888072ee11a2 R08: ffff88805b996387 R09: 1ffff1100b732c70
R10: dffffc0000000000 R11: ffffed100b732c71 R12: 000000000000003c
R13: ffffc900041bf460 R14: 0000000000002000 R15: ffff888072ee0c38
FS:  00007f67e2ffe6c0(0000) GS:ffff8881256ca000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa159255000 CR3: 0000000079001000 CR4: 0000000000350ef0

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/11 11:30 upstream dc855b77719f 441e25b7 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-kasan-gce-root kernel BUG in ext4_write_inline_data
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
2026/02/13 21:26 upstream c22e26bd0906 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs kernel BUG in ext4_write_inline_data
2026/02/12 19:58 upstream 37a93dd5c49b 504cb1bf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root kernel BUG in ext4_write_inline_data
2026/02/11 10:16 upstream dc855b77719f 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root kernel BUG in ext4_write_inline_data
2026/02/10 03:03 upstream 8a5203c630c6 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-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
2026/02/16 14:00 linux-next 635c467cc14e 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root kernel BUG in ext4_write_inline_data
* Struck through repros no longer work on HEAD.