syzbot


WARNING in ext4_iomap_overwrite_begin

Status: fixed on 2023/07/01 16:05
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+08106c4b7d60702dbc14@syzkaller.appspotmail.com
Fix commit: fa83c34e3e56 ext4: check iomap type only if ext4_iomap_begin() does not fail
First crash: 362d, last: 362d
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] ext4: check iomap type only if ext4_iomap_begin() does not fail 3 (3) 2023/05/13 04:59
[syzbot] [ext4?] WARNING in ext4_iomap_overwrite_begin 0 (1) 2023/04/19 18:52

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 30014 at fs/ext4/inode.c:3574 ext4_iomap_overwrite_begin+0x7d/0xa0
Modules linked in:
CPU: 1 PID: 30014 Comm: syz-executor.1 Not tainted 6.3.0-rc6-syzkaller-00173-g7a934f4bd7d6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
RIP: 0010:ext4_iomap_overwrite_begin+0x7d/0xa0 fs/ext4/inode.c:3574
Code: 2d 0f b7 1b bf 02 00 00 00 89 de e8 1d 15 52 ff 83 fb 02 75 10 e8 f3 11 52 ff 89 e8 5b 41 5c 41 5e 41 5f 5d c3 e8 e3 11 52 ff <0f> 0b eb ec 89 d9 80 e1 07 fe c1 38 c1 7c c8 48 89 df e8 3c d2 a7
RSP: 0018:ffffc9000a4cf0b0 EFLAGS: 00010293
RAX: ffffffff823864dd RBX: 0000000000000000 RCX: ffff88807d391d40
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: 00000000ffffff8b R08: ffffffff823864c3 R09: ffffed100f18877a
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88803d4fd2f0
R13: ffff88803d4fd2f0 R14: 0000000000010000 R15: 0000000000090000
FS:  00007fe681b6e700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2767115dc9 CR3: 000000002b556000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 iomap_iter+0x677/0xec0 fs/iomap/iter.c:91
 __iomap_dio_rw+0xd74/0x20d0 fs/iomap/direct-io.c:594
 iomap_dio_rw+0x46/0xa0 fs/iomap/direct-io.c:683
 ext4_dio_write_iter fs/ext4/file.c:597 [inline]
 ext4_file_write_iter+0x1509/0x1930 fs/ext4/file.c:708
 do_iter_write+0x6ea/0xc50 fs/read_write.c:861
 iter_file_splice_write+0x843/0xfe0 fs/splice.c:778
 do_splice_from fs/splice.c:856 [inline]
 direct_splice_actor+0xe7/0x1c0 fs/splice.c:1022
 splice_direct_to_actor+0x4c4/0xbd0 fs/splice.c:977
 do_splice_direct+0x283/0x3d0 fs/splice.c:1065
 do_sendfile+0x620/0xff0 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fe680e8c169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe681b6e168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fe680fabf80 RCX: 00007fe680e8c169
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000005
RBP: 00007fe680ee7ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000008800000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc42fc2daf R14: 00007fe681b6e300 R15: 0000000000022000
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/04/15 18:45 upstream 7a934f4bd7d6 ec410564 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in ext4_iomap_overwrite_begin
* Struck through repros no longer work on HEAD.