syzbot


KCSAN: data-race in step_into / vfs_rename

Status: closed as invalid on 2020/06/18 14:24
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 832d, last: 782d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in step_into / vfs_rename (6) 1 332d 332d 0/23 auto-closed as invalid on 2021/10/14 13:13
upstream KCSAN: data-race in step_into / vfs_rename (5) 1 375d 375d 0/23 auto-closed as invalid on 2021/08/31 22:21
upstream KCSAN: data-race in step_into / vfs_rename (2) 1 774d 774d 0/23 auto-closed as invalid on 2020/07/29 00:43
upstream KCSAN: data-race in step_into / vfs_rename (3) 3 656d 689d 0/23 auto-closed as invalid on 2020/11/24 01:44
upstream KCSAN: data-race in step_into / vfs_rename (4) 1 584d 584d 0/23 auto-closed as invalid on 2021/02/04 02:28

Sample crash report:
==================================================================
BUG: KCSAN: data-race in step_into / vfs_rename

write to 0xffff8880b55a3f00 of 4 bytes by task 11748 on cpu 1:
 dont_mount include/linux/dcache.h:352 [inline]
 vfs_rename+0x985/0x1130 fs/namei.c:4297
 do_renameat2+0x9e8/0xa50 fs/namei.c:4437
 __do_sys_rename fs/namei.c:4483 [inline]
 __se_sys_rename fs/namei.c:4481 [inline]
 __x64_sys_rename+0x44/0x60 fs/namei.c:4481
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880b55a3f00 of 4 bytes by task 5282 on cpu 0:
 __follow_mount_rcu fs/namei.c:1302 [inline]
 handle_mounts fs/namei.c:1359 [inline]
 step_into+0xb2/0x1090 fs/namei.c:1676
 open_last_lookups fs/namei.c:3178 [inline]
 path_openat+0x34e/0x23d0 fs/namei.c:3343
 do_filp_open+0x11e/0x1b0 fs/namei.c:3373
 do_sys_openat2+0x52e/0x680 fs/open.c:1148
 do_sys_open+0xa2/0x110 fs/open.c:1164
 ksys_open include/linux/syscalls.h:1386 [inline]
 __do_sys_open fs/open.c:1170 [inline]
 __se_sys_open fs/open.c:1168 [inline]
 __x64_sys_open+0x50/0x60 fs/open.c:1168
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 5282 Comm: systemd-udevd Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2020/06/15 18:47 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 8e3ab941 .config log report
ci2-upstream-kcsan-gce 2020/04/27 05:22 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 0ce7569e .config log report