syzbot


kernel BUG in ext4_write_inline_data (3)

Status: upstream: reported C repro on 2025/09/13 15:21
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+f3185be57d7e8dda32b8@syzkaller.appspotmail.com
Fix commit: ext4: refresh inline data size before write operations
Patched on: [ci-upstream-linux-next-kasan-gce-root ci-upstream-rust-kasan-gce], missing on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 82d, last: 22d
Cause bisection: failed (error log, bisect log)
  
Discussions (5)
Title Replies (including bot) Last reply
[PATCH v2] ext4: refresh inline data size before write operations 4 (4) 2025/11/17 19:13
[PATCH v2] ext4: synchronize free block counter when detecting corruption 3 (3) 2025/11/11 08:45
[syzbot] [ext4?] kernel BUG in ext4_write_inline_data (3) 0 (9) 2025/11/11 04:50
[PATCH] ext4: fix inline data overflow when xattr value is empty 2 (2) 2025/10/19 01:04
[PATCH] Fix: ext4: add sanity check for inode inline write range 6 (6) 2025/10/10 11:31
Similar bugs (9)
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 1026d 1122d 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 1050d 1873d 22/29 fixed on 2023/02/24 13:50
upstream kernel BUG in ext4_write_inline_data ext4 -1 C error 36 504d 989d 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 157d 265d 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 26 22d 881d 0/2 upstream: reported C repro on 2023/07/02 21:30
linux-4.19 kernel BUG in ext4_write_inline_data_end ext4 -1 C error 12 1003d 1750d 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 160d 374d 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 1022d 1120d 2/2 fixed on 2023/05/04 14:51
android-54 kernel BUG in ext4_write_inline_data -1 C 3 1082d 1120d 2/2 fixed on 2023/04/05 17:17
Last patch testing requests (10)
Created Duration User Patch Repo Result
2025/11/11 04:50 36m albinbabuvarghese20@gmail.com patch upstream report log
2025/11/11 01:12 24m albinbabuvarghese20@gmail.com patch upstream report log
2025/11/10 21:36 24m albinbabuvarghese20@gmail.com patch upstream OK log
2025/11/08 00:06 17m retest repro upstream report log
2025/10/21 00:26 34m retest repro upstream report log
2025/10/21 00:26 18m retest repro upstream report log
2025/10/20 05:07 23m kartikey406@gmail.com patch upstream report log
2025/10/18 15:11 22m kartikey406@gmail.com patch upstream report log
2025/10/09 01:34 1h17m albinbabuvarghese20@gmail.com patch upstream OK log
2025/10/07 22:19 26m eraykrdg1@gmail.com patch upstream OK log

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: 7460 Comm: syz.5.349 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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 fa b0 b0 ff 4c 89 fa e9 06 ff ff ff e8 2d 07 4c ff 90 0f 0b e8 25 07 4c ff 90 <0f> 0b 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f
RSP: 0018:ffffc9000bff7828 EFLAGS: 00010293
RAX: ffffffff82726f5b RBX: 0000000000000078 RCX: ffff888026215ac0
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000078
RBP: ffff8880773424a2 R08: ffff8880599a2387 R09: 1ffff1100b334470
R10: dffffc0000000000 R11: ffffed100b334471 R12: 000000000000003c
R13: ffffc9000bff78e0 R14: 0000000000000000 R15: ffff888077341f48
FS:  00007f61146ab6c0(0000) GS:ffff888126380000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdcd7e1e000 CR3: 0000000010f34000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 ext4_write_inline_data_end+0x336/0xab0 fs/ext4/inline.c:807
 generic_perform_write+0x62a/0x900 mm/filemap.c:4196
 ext4_buffered_write_iter+0xce/0x3a0 fs/ext4/file.c:299
 ext4_file_write_iter+0x298/0x1bc0 fs/ext4/file.c:-1
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f611378eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f61146ab038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f61139e5fa0 RCX: 00007f611378eec9
RDX: 0000000000000078 RSI: 0000200000000600 RDI: 0000000000000005
RBP: 00007f6113811f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f61139e6038 R14: 00007f61139e5fa0 R15: 00007fff25d44648
 </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 fa b0 b0 ff 4c 89 fa e9 06 ff ff ff e8 2d 07 4c ff 90 0f 0b e8 25 07 4c ff 90 <0f> 0b 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f
RSP: 0018:ffffc9000bff7828 EFLAGS: 00010293
RAX: ffffffff82726f5b RBX: 0000000000000078 RCX: ffff888026215ac0
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000078
RBP: ffff8880773424a2 R08: ffff8880599a2387 R09: 1ffff1100b334470
R10: dffffc0000000000 R11: ffffed100b334471 R12: 000000000000003c
R13: ffffc9000bff78e0 R14: 0000000000000000 R15: ffff888077341f48
FS:  00007f61146ab6c0(0000) GS:ffff888126380000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efcc67a1d58 CR3: 0000000010f34000 CR4: 0000000000350ef0

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/03 01:54 upstream 7f7072574127 49379ee0 .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
2025/10/23 11:31 upstream 250a17e8f955 c0460fcd .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-kasan-gce-root kernel BUG in ext4_write_inline_data
2025/10/06 21:12 upstream fd94619c4336 91305dbe .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-kasan-gce-root kernel BUG in ext4_write_inline_data
2025/10/24 01:58 upstream 266ee584e55e c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs kernel BUG in ext4_write_inline_data
2025/10/06 13:46 upstream fd94619c4336 91305dbe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs kernel BUG in ext4_write_inline_data
2025/09/10 18:46 linux-next 5f540c4aade9 fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root kernel BUG in ext4_write_inline_data
2025/09/09 15:10 linux-next 65dd046ef558 d291dd2d .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.