syzbot


KCSAN: data-race in select_collect / step_into

Status: auto-obsoleted due to no activity on 2023/12/25 00:08
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+638149d92346cbf3013c@syzkaller.appspotmail.com
First crash: 110d, last: 110d

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

write to 0xffff8881066e9900 of 4 bytes by task 10517 on cpu 0:
 d_lru_del fs/dcache.c:437 [inline]
 select_collect+0xb3/0x2a0 fs/dcache.c:1565
 d_walk+0x291/0x460 fs/dcache.c:1386
 shrink_dcache_parent+0x85/0x1a0 fs/dcache.c:1625
 vfs_rmdir+0x283/0x2f0 fs/namei.c:4193
 do_rmdir+0x194/0x320 fs/namei.c:4248
 __do_sys_rmdir fs/namei.c:4267 [inline]
 __se_sys_rmdir fs/namei.c:4265 [inline]
 __x64_sys_rmdir+0x30/0x40 fs/namei.c:4265
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff8881066e9900 of 4 bytes by task 10516 on cpu 1:
 __d_entry_type include/linux/dcache.h:386 [inline]
 d_is_symlink include/linux/dcache.h:416 [inline]
 step_into+0x12f/0x800 fs/namei.c:1845
 open_last_lookups fs/namei.c:3569 [inline]
 path_openat+0x10da/0x1d70 fs/namei.c:3776
 do_filp_open+0xf6/0x200 fs/namei.c:3809
 do_sys_openat2+0xab/0x110 fs/open.c:1440
 do_sys_open fs/open.c:1455 [inline]
 __do_sys_openat fs/open.c:1471 [inline]
 __se_sys_openat fs/open.c:1466 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1466
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00080000 -> 0x00008000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10516 Comm: syz-executor.5 Not tainted 6.6.0-syzkaller-14651-gd2f51b3516da #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/06 17:14 upstream d2f51b3516da 78fae24e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in select_collect / step_into
* Struck through repros no longer work on HEAD.