syzbot


KCSAN: data-race in do_signal_stop / task_dump_owner

Status: auto-closed as invalid on 2020/06/18 14:03
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 936d, last: 936d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in do_signal_stop / task_dump_owner (2) 1 714d 714d 0/24 auto-closed as invalid on 2021/01/18 08:17

Sample crash report:
==================================================================
BUG: KCSAN: data-race in do_signal_stop / task_dump_owner

write to 0xffff8880ab2640a4 of 4 bytes by task 18257 on cpu 1:
 freezer_do_not_count include/linux/freezer.h:109 [inline]
 freezable_schedule include/linux/freezer.h:171 [inline]
 do_signal_stop+0x1cf/0x4e0 kernel/signal.c:2395
 get_signal+0x601/0x1290 kernel/signal.c:2699
 do_signal+0x2b/0x840 arch/x86/kernel/signal.c:784
 exit_to_usermode_loop+0x24a/0x2c0 arch/x86/entry/common.c:161
 prepare_exit_to_usermode+0x194/0x1e0 arch/x86/entry/common.c:196
 swapgs_restore_regs_and_return_to_usermode+0x0/0x40

read to 0xffff8880ab2640a4 of 4 bytes by task 18260 on cpu 0:
 task_dump_owner+0x42/0x250 fs/proc/base.c:1789
 pid_update_inode+0x35/0x70 fs/proc/base.c:1931
 pid_revalidate+0x89/0x110 fs/proc/base.c:1954
 d_revalidate fs/namei.c:754 [inline]
 d_revalidate fs/namei.c:751 [inline]
 lookup_fast+0x38c/0x3a0 fs/namei.c:1486
 walk_component+0x6a/0x390 fs/namei.c:1842
 link_path_walk.part.0+0x37a/0x700 fs/namei.c:2166
 link_path_walk fs/namei.c:2098 [inline]
 path_openat+0x191/0x23d0 fs/namei.c:3342
 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: 18260 Comm: syz-executor.2 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2020/05/06 03:26 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 35b8eb30 .config log report
* Struck through repros no longer work on HEAD.