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kernel BUG in ext4_writepages

Status: upstream: reported C repro on 2023/03/13 06:22
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+84277fde3a1f96f51f90@syzkaller.appspotmail.com
First crash: 1035d, last: 2d00h
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2023/05/07 upstream (ToT) fc4354c6e5c2 C [report] kernel BUG in ext4_do_writepages
▶ ▼ Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 kernel BUG at fs/ext4/inode.c:LINE! ext4 -1 C error 145 1041d 1915d 0/1 upstream: reported C repro on 2020/10/14 01:19
android-54 kernel BUG at fs/ext4/inode.c:LINE! ext4 -1 C 272 230d 2189d 0/2 upstream: reported C repro on 2020/01/14 12:13
linux-4.14 kernel BUG at fs/ext4/inode.c:LINE! ext4 -1 C 11 1049d 1843d 0/1 upstream: reported C repro on 2020/12/25 03:51
linux-6.1 kernel BUG in ext4_writepages origin:upstream -1 C 256 2d23h 1036d 0/3 upstream: reported C repro on 2023/03/12 17:26
android-5-15 kernel BUG in ext4_writepages ext4 origin:upstream -1 C error 534 3d15h 1181d 0/2 upstream: reported C repro on 2022/10/18 14:12
android-5-10 kernel BUG in ext4_writepages -1 C error 5 1181d 1342d 2/2 fixed on 2022/11/16 18:44
android-6-1 kernel BUG in ext4_writepages origin:upstream -1 C error 305 4d16h 951d 0/2 upstream: reported C repro on 2023/06/05 07:33
upstream kernel BUG in mpage_prepare_extent_to_map ext4 -1 C done error 145 1125d 1686d 0/29 auto-obsoleted due to no activity on 2024/03/07 20:46
android-5-10 kernel BUG in ext4_writepages (2) ext4 -1 C error inconclusive 388 10d 1141d 0/2 upstream: reported C repro on 2022/11/27 00:51
▶ ▼ Last patch testing requests (10)
Created Duration User Patch Repo Result
2025/11/16 03:21 16m retest repro linux-5.15.y report log
2025/11/16 03:21 17m retest repro linux-5.15.y report log
2025/11/16 03:21 10m retest repro linux-5.15.y report log
2025/11/16 03:21 10m retest repro linux-5.15.y report log
2025/11/16 03:21 11m retest repro linux-5.15.y report log
2025/10/01 22:07 1h55m retest repro linux-5.15.y report log
2025/10/01 22:07 1h50m retest repro linux-5.15.y report log
2025/10/01 22:07 12m retest repro linux-5.15.y report log
2025/10/01 22:07 13m retest repro linux-5.15.y report log
2025/10/01 22:07 9m retest repro linux-5.15.y report log
▶ ▼ Fix bisection attempts (2)
Created Duration User Patch Repo Result
2023/10/12 20:22 0m bisect fix linux-5.15.y error job log
2023/04/26 05:38 39m bisect fix linux-5.15.y OK (0) job log log

Sample crash report:
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_macvtap: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready
------------[ cut here ]------------
kernel BUG at fs/ext4/inode.c:2734!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 4223 Comm: kworker/u4:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: writeback wb_workfn
 (flush-7:1)
RIP: 0010:ext4_writepages+0x2d12/0x2d20 fs/ext4/inode.c:2733
Code: c1 03 38 c1 0f 8c b0 fd ff ff 4c 89 e7 e8 16 d0 b2 ff e9 a3 fd ff ff e8 0c 68 6e ff 0f 0b e8 05 68 6e ff 0f 0b e8 fe 67 6e ff <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 66 90 41 57 41 56 53 48 89 fb
RSP: 0018:ffffc90002f8f080 EFLAGS: 00010293

RAX: ffffffff82096252 RBX: 000000c41000c000 RCX: ffff88801e66bb80
RDX: 0000000000000000 RSI: 0000008000000000 RDI: 0000000000000000
RBP: ffffc90002f8f3d0 R08: dffffc0000000000 R09: ffffed100ae5f14a
R10: ffffed100ae5f14a R11: 1ffff1100ae5f149 R12: 1ffff920005f1ee6
R13: dffffc0000000000 R14: 0000008000000000 R15: ffff88802383a000
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c0083e9000 CR3: 00000000595ae000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 do_writepages+0x48d/0x6d0 mm/page-writeback.c:2386
 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1647
 writeback_sb_inodes+0x9fe/0x1610 fs/fs-writeback.c:1930
 wb_writeback+0x443/0xb90 fs/fs-writeback.c:2104
 wb_do_writeback fs/fs-writeback.c:2247 [inline]
 wb_workfn+0x423/0xe60 fs/fs-writeback.c:2288
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Modules linked in:
---[ end trace 7427e2461e7e16d4 ]---
RIP: 0010:ext4_writepages+0x2d12/0x2d20 fs/ext4/inode.c:2733
Code: c1 03 38 c1 0f 8c b0 fd ff ff 4c 89 e7 e8 16 d0 b2 ff e9 a3 fd ff ff e8 0c 68 6e ff 0f 0b e8 05 68 6e ff 0f 0b e8 fe 67 6e ff <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 66 90 41 57 41 56 53 48 89 fb
RSP: 0018:ffffc90002f8f080 EFLAGS: 00010293

RAX: ffffffff82096252 RBX: 000000c41000c000 RCX: ffff88801e66bb80
RDX: 0000000000000000 RSI: 0000008000000000 RDI: 0000000000000000
RBP: ffffc90002f8f3d0 R08: dffffc0000000000 R09: ffffed100ae5f14a
R10: ffffed100ae5f14a R11: 1ffff1100ae5f149 R12: 1ffff920005f1ee6
R13: dffffc0000000000 R14: 0000008000000000 R15: ffff88802383a000
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555827c35c8 CR3: 000000007e128000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (245):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/09 01:54 linux-5.15.y 29e53a5b1c4f 7e2882b3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/01/11 23:09 linux-5.15.y 4735586da88e 6dbc6a9b .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2024/12/01 19:00 linux-5.15.y 0a51d2d4527b 68914665 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2024/08/20 08:07 linux-5.15.y fa93fa65db6e 9f0ab3fb .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2024/04/05 16:14 linux-5.15.y 9465fef4ae35 77230c29 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2024/01/02 07:40 linux-5.15.y d93fa2c78854 fb427a07 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2023/12/31 02:46 linux-5.15.y d93fa2c78854 fb427a07 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2023/11/18 12:48 linux-5.15.y 80529b4968a8 cb976f63 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2023/07/12 13:07 linux-5.15.y d54cfc420586 2f19aa4f .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2023/06/23 03:12 linux-5.15.y f67653019430 79782afc .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2023/03/27 03:52 linux-5.15.y 115472395b0a fbf0499a .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2023/03/26 20:09 linux-5.15.y 115472395b0a fbf0499a .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/06/18 07:48 linux-5.15.y 1c700860e8bc e77fae15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan-arm64 kernel BUG in ext4_writepages
2025/04/23 09:39 linux-5.15.y f7347f400572 53a8b9bd .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2] ci2-linux-5-15-kasan-arm64 kernel BUG in ext4_writepages
2023/03/13 06:22 linux-5.15.y bbf9f29bac04 5205ef30 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 kernel BUG in ext4_writepages
2023/06/25 20:17 linux-5.15.y f67653019430 79782afc .config console log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2026/01/09 17:12 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2026/01/09 07:43 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2026/01/09 04:20 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2026/01/09 02:22 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2026/01/08 03:49 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2026/01/07 08:35 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2026/01/07 07:01 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2026/01/05 18:17 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2026/01/04 15:47 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2026/01/03 17:48 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2026/01/03 08:02 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2026/01/01 22:25 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2026/01/01 08:29 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/31 15:33 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/31 01:52 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/31 00:15 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/30 17:46 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/30 11:32 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/29 19:21 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/29 07:21 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/29 05:53 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/28 20:21 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/27 19:33 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/27 16:01 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/27 05:32 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/26 00:46 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/25 16:17 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/25 05:00 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/24 01:49 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/23 14:37 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/22 05:32 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/21 05:22 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/21 03:11 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/19 17:28 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/18 14:39 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/18 05:33 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/16 07:13 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/14 10:06 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/14 01:22 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/13 15:30 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/10 20:32 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/10 20:13 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/10 18:36 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/10 17:58 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/12/03 22:32 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2024/02/24 15:30 linux-5.15.y 458ce51d0356 8d446f15 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2023/12/05 11:17 linux-5.15.y 9b91d36ba301 f819d6f7 .config console log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan kernel BUG in ext4_writepages
2025/08/07 04:45 linux-5.15.y c79648372d02 9a42d6b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 kernel BUG in ext4_writepages
* Struck through repros no longer work on HEAD.