syzbot


WARNING in ext4_iomap_begin

Status: upstream: reported on 2025/08/27 01:08
Reported-by: syzbot+374b2823c721a4f21fec@syzkaller.appspotmail.com
First crash: 2d12h, last: 2d12h
Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 WARNING in ext4_iomap_begin (2) origin:upstream -1 C done 10 74d 159d 3/3 fixed on 2025/07/16 19:57
linux-6.1 WARNING in ext4_iomap_begin -1 1 765d 765d 0/3 auto-obsoleted due to no activity on 2023/11/02 21:33
upstream WARNING in ext4_iomap_begin ext4 -1 C inconclusive error 16 1114d 1142d 0/29 auto-obsoleted due to no activity on 2023/04/04 00:54
linux-6.1 WARNING in ext4_iomap_begin (3) -1 1 4d21h 4d21h 0/3 upstream: reported on 2025/08/24 16:23
upstream WARNING in ext4_iomap_begin (2) ext4 -1 C done 7 689d 804d 25/29 fixed on 2023/12/21 03:45
linux-5.15 WARNING in ext4_iomap_begin origin:upstream -1 C done 8 81d 114d 3/3 fixed on 2025/07/14 10:31
upstream WARNING in ext4_iomap_begin (3) ext4 -1 C inconclusive 65 1d21h 302d 0/29 upstream: reported C repro on 2024/10/31 12:34
linux-5.15 WARNING in ext4_iomap_begin (2) origin:upstream -1 C 7 9d04h 18d 0/3 upstream: reported C repro on 2025/08/11 00:02

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 11782 at fs/ext4/inode.c:3388 ext4_iomap_begin+0x95f/0xad0 fs/ext4/inode.c:3388
Modules linked in:
CPU: 1 PID: 11782 Comm: syz.8.1506 Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:ext4_iomap_begin+0x95f/0xad0 fs/ext4/inode.c:3388
Code: 3b 84 24 00 01 00 00 75 6d 44 89 f0 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 cb 5c 55 ff e9 77 ff ff ff e8 c1 5c 55 ff <0f> 0b 41 be de ff ff ff 49 bf 00 00 00 00 00 fc ff df eb 88 89 d9
RSP: 0018:ffffc900043af060 EFLAGS: 00010283
RAX: ffffffff82302e5f RBX: ffff888055ef838a RCX: 0000000000080000
RDX: ffffc9000c579000 RSI: 0000000000016c97 RDI: 0000000000016c98
RBP: ffffc900043af1b0 R08: ffff888055ef8057 R09: 1ffff1100abdf00a
R10: dffffc0000000000 R11: ffffed100abdf00b R12: 00000000000000d4
R13: 1ffff1100abdf071 R14: 000000000000000b R15: 0000000000000000
FS:  00007f013b9616c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f37df8659f0 CR3: 000000002dc98000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 iomap_iter+0x6b1/0xec0 fs/iomap/iter.c:91
 __iomap_dio_rw+0xb9c/0x1c40 fs/iomap/direct-io.c:658
 iomap_dio_rw+0x45/0xa0 fs/iomap/direct-io.c:748
 ext4_dio_write_iter fs/ext4/file.c:577 [inline]
 ext4_file_write_iter+0x13ff/0x1870 fs/ext4/file.c:696
 do_iter_readv_writev fs/read_write.c:-1 [inline]
 do_iter_write+0x79a/0xc70 fs/read_write.c:860
 iter_file_splice_write+0x66f/0xc50 fs/splice.c:736
 do_splice_from fs/splice.c:933 [inline]
 direct_splice_actor+0xe8/0x130 fs/splice.c:1142
 splice_direct_to_actor+0x2f0/0x870 fs/splice.c:1088
 do_splice_direct+0x1b7/0x2c0 fs/splice.c:1194
 do_sendfile+0x5dc/0xf70 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64+0x13f/0x190 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f013ab8ebe9
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:00007f013b961038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f013adb5fa0 RCX: 00007f013ab8ebe9
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004
RBP: 00007f013ac11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020fffe82 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f013adb6038 R14: 00007f013adb5fa0 R15: 00007fff38cf5d68
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/27 01:07 linux-6.6.y bb9c90ab9c5a e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in ext4_iomap_begin
* Struck through repros no longer work on HEAD.