KCSAN: data-race in __ext4_unlink / __ext4_update_other_inode_time

Status: auto-closed as invalid on 2021/02/13 03:24
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+2948cdc08a7001ecf1e5@syzkaller.appspotmail.com
First crash: 2118d, last: 2039d
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __ext4_unlink / __ext4_update_other_inode_time (3) ext4 6 13 1822d 1906d 0/29 auto-closed as invalid on 2021/09/18 02:16
upstream KCSAN: data-race in __ext4_unlink / __ext4_update_other_inode_time (4) ext4 6 3 1763d 1783d 0/29 auto-closed as invalid on 2021/11/16 07:48
upstream KCSAN: data-race in __ext4_unlink / __ext4_update_other_inode_time (2) ext4 6 2 1952d 1976d 0/29 auto-closed as invalid on 2021/05/17 11:36

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __ext4_unlink / __ext4_update_other_inode_time

write to 0xffff88800f6bf240 of 8 bytes by task 24306 on cpu 1:
 __ext4_unlink+0x4c3/0x6a0 fs/ext4/namei.c:3233
 ext4_unlink+0x1f1/0x3f0 fs/ext4/namei.c:3268
 vfs_unlink+0x232/0x3b0 fs/namei.c:3835
 do_unlinkat+0x28a/0x4d0 fs/namei.c:3899
 __do_sys_unlink fs/namei.c:3945 [inline]
 __se_sys_unlink fs/namei.c:3943 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:3943
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88800f6bf240 of 8 bytes by task 8456 on cpu 0:
 ext4_encode_extra_time fs/ext4/ext4.h:891 [inline]
 __ext4_update_other_inode_time+0x14f/0x550 fs/ext4/inode.c:4979
 ext4_update_other_inodes_time fs/ext4/inode.c:5011 [inline]
 ext4_do_update_inode fs/ext4/inode.c:5140 [inline]
 ext4_mark_iloc_dirty+0x1286/0x1650 fs/ext4/inode.c:5721
 __ext4_mark_inode_dirty+0x4cd/0x5d0 fs/ext4/inode.c:5915
 __ext4_unlink+0x66e/0x6a0 fs/ext4/namei.c:3220
 ext4_unlink+0x1f1/0x3f0 fs/ext4/namei.c:3268
 vfs_unlink+0x232/0x3b0 fs/namei.c:3835
 do_unlinkat+0x28a/0x4d0 fs/namei.c:3899
 __do_sys_unlink fs/namei.c:3945 [inline]
 __se_sys_unlink fs/namei.c:3943 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:3943
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8456 Comm: syz-executor.3 Not tainted 5.11.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/01/09 03:23 upstream 6279d812eab6 c104d4a3 .config console log report info ci2-upstream-kcsan-gce
2021/01/04 09:11 upstream e71ba9452f0b 79264ae3 .config console log report info ci2-upstream-kcsan-gce
2020/12/30 23:20 upstream f6e1ea196492 ecb8c012 .config console log report info ci2-upstream-kcsan-gce
2020/12/19 03:11 upstream 3644e2d2dda7 04201c06 .config console log report info ci2-upstream-kcsan-gce
2020/12/18 14:07 upstream a409ed156a90 04201c06 .config console log report info ci2-upstream-kcsan-gce
2020/12/14 22:36 upstream fab0fca1da5c 97183ed7 .config console log report info ci2-upstream-kcsan-gce
2020/12/05 09:07 upstream b3298500b23f 0ef84591 .config console log report info ci2-upstream-kcsan-gce
2020/11/18 05:18 upstream 111e91a6df50 09323409 .config console log report info ci2-upstream-kcsan-gce
2020/10/23 00:24 upstream 96485e446260 4e740c00 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.