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WARNING in iomap_iter (6)

Status: upstream: reported on 2026/01/26 14:07
Subsystems: iomap
[Documentation on labels]
Reported-by: syzbot+bd5ca596a01d01bfa083@syzkaller.appspotmail.com
First crash: 7d10h, last: 7d10h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [iomap?] WARNING in iomap_iter (6) 0 (1) 2026/01/26 14:07
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in iomap_iter (4) iomap erofs -1 C done 1 444d 440d 28/29 fixed on 2024/12/16 09:50
upstream WARNING in iomap_iter (5) erofs iomap -1 C done 6 229d 230d 29/29 fixed on 2025/08/06 17:37
linux-6.1 WARNING in iomap_iter origin:lts-only -1 C done 25 346d 668d 0/3 upstream: reported C repro on 2024/04/01 07:45
upstream WARNING in iomap_iter (3) erofs -1 C done 29 473d 471d 0/29 closed as invalid on 2024/10/15 10:39
upstream WARNING in iomap_iter iomap -1 C inconclusive 141 1116d 1543d 22/29 fixed on 2023/06/12 19:24
upstream WARNING in iomap_iter (2) iomap -1 C 4 641d 637d 25/29 fixed on 2024/06/05 13:52

Sample crash report:
------------[ cut here ]------------
iter->iomap.offset + iter->iomap.length <= iter->pos
WARNING: fs/iomap/iter.c:36 at iomap_iter_done fs/iomap/iter.c:36 [inline], CPU#0: kworker/u8:26/9724
WARNING: fs/iomap/iter.c:36 at iomap_iter+0x982/0xf30 fs/iomap/iter.c:114, CPU#0: kworker/u8:26/9724
Modules linked in:
CPU: 0 UID: 0 PID: 9724 Comm: kworker/u8:26 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Workqueue: loop6 loop_workfn
RIP: 0010:iomap_iter_done fs/iomap/iter.c:36 [inline]
RIP: 0010:iomap_iter+0x982/0xf30 fs/iomap/iter.c:114
Code: ff ff ff e9 86 fa ff ff e8 ab 6d 65 ff 90 0f 0b 90 e9 06 fd ff ff e8 9d 6d 65 ff 90 0f 0b 90 e9 3b fd ff ff e8 8f 6d 65 ff 90 <0f> 0b 90 e9 97 fd ff ff e8 81 6d 65 ff 90 0f 0b 90 e9 c4 fd ff ff
RSP: 0018:ffffc9000cdcf268 EFLAGS: 00010293
RAX: ffffffff825d2b81 RBX: ffffc9000cdcf3c0 RCX: ffff88806e5d1e80
RDX: 0000000000000000 RSI: 8000000000083fff RDI: 0000003e80000000
RBP: ffffc9000cdcf3f8 R08: ffffc9000cdcf3e8 R09: ffffc9000cdcf430
R10: dffffc0000000000 R11: ffffffff8473db20 R12: 8000000000083fff
R13: ffffc9000cdcf402 R14: 1ffff920019b9e79 R15: 0000003e80000000
FS:  0000000000000000(0000) GS:ffff888125928000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000031712ff8 CR3: 0000000043618000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 iomap_file_buffered_write+0x275/0xa30 fs/iomap/buffered-io.c:1187
 blkdev_buffered_write block/fops.c:736 [inline]
 blkdev_write_iter+0x524/0x710 block/fops.c:802
 lo_rw_aio+0xc7a/0xf00 include/linux/percpu-rwsem.h:-1
 do_req_filebacked drivers/block/loop.c:434 [inline]
 loop_handle_cmd drivers/block/loop.c:1947 [inline]
 loop_process_work+0x61d/0x11a0 drivers/block/loop.c:1982
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
 worker_thread+0x89f/0xd90 kernel/workqueue.c:3421
 kthread+0x726/0x8b0 kernel/kthread.c:463
 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/22 14:01 upstream a66191c590b3 2367ed1e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in iomap_iter
* Struck through repros no longer work on HEAD.