syzbot


WARNING in ext4_iomap_begin (2)

Status: fixed on 2023/12/21 03:45
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+307da6ca5cb0d01d581a@syzkaller.appspotmail.com
Fix commit: ce56d21355cd ext4: fix racy may inline data check in dio write
First crash: 311d, last: 193d
Cause bisection: introduced by (bisect log) :
commit 310ee0902b8d9d0a13a5a13e94688a5863fa29c2
Author: Brian Foster <bfoster@redhat.com>
Date: Tue Mar 14 13:07:59 2023 +0000

  ext4: allow concurrent unaligned dio overwrites

Crash: WARNING in ext4_iomap_begin (log)
Repro: C syz .config
  
Discussions (3)
Title Replies (including bot) Last reply
[Linux kernel bug] WARNING in ext4_iomap_begin 1 (1) 2024/04/16 13:25
[PATCH] ext4: fix racy may inline data check in dio write 1 (1) 2023/10/02 18:50
[syzbot] [ext4?] WARNING in ext4_iomap_begin (2) 2 (7) 2023/09/29 19:40
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 WARNING in ext4_iomap_begin 1 269d 269d 0/3 auto-obsoleted due to no activity on 2023/11/02 21:33
upstream WARNING in ext4_iomap_begin ext4 C inconclusive error 16 618d 645d 0/26 auto-obsoleted due to no activity on 2023/04/04 00:54
Last patch testing requests (2)
Created Duration User Patch Repo Result
2023/09/29 19:19 19m bfoster@redhat.com patch upstream OK log
2023/09/29 17:24 19m bfoster@redhat.com patch upstream OK log

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5195 at fs/ext4/inode.c:3338 ext4_iomap_begin+0xa9b/0xd30
Modules linked in:
CPU: 0 PID: 5195 Comm: syz-executor392 Not tainted 6.6.0-rc3-syzkaller-00055-g9ed22ae6be81 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
RIP: 0010:ext4_iomap_begin+0xa9b/0xd30 fs/ext4/inode.c:3338
Code: d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 ce 3d 4c ff 49 be 00 00 00 00 00 fc ff df 48 8b 5c 24 48 e9 65 ff ff ff e8 b5 3d 4c ff <0f> 0b 41 bc de ff ff ff e9 8f f6 ff ff 89 d9 80 e1 07 38 c1 0f 8c
RSP: 0018:ffffc9000405f580 EFLAGS: 00010293
RAX: ffffffff8241ccbb RBX: 0000000010000000 RCX: ffff88802234d940
RDX: 0000000000000000 RSI: 00000000000000bc RDI: 0000000000000000
RBP: ffffc9000405f6f0 R08: ffffffff8241c408 R09: 1ffff1100eff5b4a
R10: dffffc0000000000 R11: ffffed100eff5b4b R12: 00000000000000bc
R13: 1ffff1100eff5baf R14: 000000000000000b R15: 0000000000000016
FS:  00007f68b788c6c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f68b788cd58 CR3: 000000006b9c0000 CR4: 00000000003506f0
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+0xe2e/0x2370 fs/iomap/direct-io.c:658
 iomap_dio_rw+0x46/0xa0 fs/iomap/direct-io.c:748
 ext4_dio_write_iter fs/ext4/file.c:605 [inline]
 ext4_file_write_iter+0x165f/0x1ad0 fs/ext4/file.c:715
 call_write_iter include/linux/fs.h:1956 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x782/0xaf0 fs/read_write.c:584
 ksys_pwrite64 fs/read_write.c:699 [inline]
 __do_sys_pwrite64 fs/read_write.c:709 [inline]
 __se_sys_pwrite64 fs/read_write.c:706 [inline]
 __x64_sys_pwrite64+0x1aa/0x230 fs/read_write.c:706
 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: 0033:0x7f68bfbf0b59
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 18 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f68b788c218 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f68b788c6c0 RCX: 00007f68bfbf0b59
RDX: 0000000000000001 RSI: 0000000020000100 RDI: 0000000000000005
RBP: 00007f68bfc796d8 R08: 00007ffd6a04dbc7 R09: 0000000000000000
R10: 000000000000b114 R11: 0000000000000246 R12: ffffffffffffffb0
R13: 00007f68bfc796d0 R14: 00007f68bfc45840 R15: 0030656c69662f2e
 </TASK>

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/09/29 08:20 upstream 9ed22ae6be81 d265efd8 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs WARNING in ext4_iomap_begin
2023/10/09 20:03 upstream 94f6f0550c62 3c53c7d9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in ext4_iomap_begin
2023/09/29 07:48 upstream 9ed22ae6be81 d265efd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in ext4_iomap_begin
2023/09/27 05:32 upstream 50768a425b46 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in ext4_iomap_begin
2023/06/23 03:09 upstream 8a28a0b6f1a1 09ffe269 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in ext4_iomap_begin
2023/06/17 09:15 upstream 1639fae5132b f3921d4d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in ext4_iomap_begin
2023/06/13 03:17 linux-next 715abedee4cd 749afb64 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in ext4_iomap_begin
* Struck through repros no longer work on HEAD.