syzbot


WARNING in ext4_iomap_begin (3)

Status: upstream: reported on 2025/08/24 16:23
Reported-by: syzbot+4d0d5a13be3a5e4cba95@syzkaller.appspotmail.com
First crash: 13d, last: 8d21h
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 83d 168d 3/3 fixed on 2025/07/16 19:57
linux-6.6 WARNING in ext4_iomap_begin -1 1 11d 11d 0/2 upstream: reported on 2025/08/27 01:08
linux-6.1 WARNING in ext4_iomap_begin -1 1 774d 774d 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 1123d 1151d 0/29 auto-obsoleted due to no activity on 2023/04/04 00:54
upstream WARNING in ext4_iomap_begin (2) ext4 -1 C done 7 698d 813d 25/29 fixed on 2023/12/21 03:45
linux-5.15 WARNING in ext4_iomap_begin origin:upstream -1 C done 8 90d 123d 3/3 fixed on 2025/07/14 10:31
upstream WARNING in ext4_iomap_begin (3) ext4 -1 C inconclusive 67 10h33m 311d 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 2d19h 27d 0/3 upstream: reported C repro on 2025/08/11 00:02

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5056 at fs/ext4/inode.c:3466 ext4_iomap_begin+0x977/0xae0 fs/ext4/inode.c:3466
Modules linked in:
CPU: 0 PID: 5056 Comm: syz.4.172 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:ext4_iomap_begin+0x977/0xae0 fs/ext4/inode.c:3466
Code: 3b 84 24 20 01 00 00 75 6d 44 89 f0 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 e3 ef 5e ff e9 73 ff ff ff e8 d9 ef 5e ff <0f> 0b 41 be de ff ff ff 49 bf 00 00 00 00 00 fc ff df eb 85 89 d9
RSP: 0018:ffffc90005bf7020 EFLAGS: 00010283
RAX: ffffffff8221e047 RBX: ffff88807070bfaa RCX: 0000000000080000
RDX: ffffc9000caa9000 RSI: 0000000000007fb2 RDI: 0000000000007fb3
RBP: ffffc90005bf7190 R08: dffffc0000000000 R09: ffffed100e0e1791
R10: ffffed100e0e1791 R11: 1ffff1100e0e1790 R12: 00000000000000d4
R13: 1ffff1100e0e17f5 R14: 000000000000000b R15: 0000000000000000
FS:  00007f6b92fd26c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffff6499b9c CR3: 00000000754e7000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 iomap_iter+0x6c6/0x1040 fs/iomap/iter.c:91
 __iomap_dio_rw+0xcba/0x1dd0 fs/iomap/direct-io.c:601
 iomap_dio_rw+0x41/0xa0 fs/iomap/direct-io.c:690
 ext4_dio_write_iter fs/ext4/file.c:557 [inline]
 ext4_file_write_iter+0x1262/0x16e0 fs/ext4/file.c:677
 do_iter_readv_writev fs/read_write.c:-1 [inline]
 do_iter_write+0x62d/0xaf0 fs/read_write.c:861
 iter_file_splice_write+0x665/0xc50 fs/splice.c:685
 do_splice_from fs/splice.c:763 [inline]
 direct_splice_actor+0xe1/0x130 fs/splice.c:950
 splice_direct_to_actor+0x480/0xb60 fs/splice.c:896
 do_splice_direct+0x1b0/0x2b0 fs/splice.c:1002
 do_sendfile+0x5cc/0xeb0 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64+0x13b/0x190 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6b9218ebe9
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:00007f6b92fd2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f6b923b5fa0 RCX: 00007f6b9218ebe9
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005
RBP: 00007f6b92211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000ff7e82 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6b923b6038 R14: 00007f6b923b5fa0 R15: 00007fff0c5f97b8
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/29 16:01 linux-6.1.y f89b6e15694c 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_iomap_begin
2025/08/24 16:23 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in ext4_iomap_begin
* Struck through repros no longer work on HEAD.