syzbot


KCSAN: data-race in do_signal_stop / ns_capable

Status: auto-closed as invalid on 2021/01/03 16:05
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+a1efbd1f0915d739a8a4@syzkaller.appspotmail.com
First crash: 1253d, last: 1253d

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

read-write to 0xffff88801f4fb064 of 4 bytes by task 25816 on cpu 1:
 ns_capable_common kernel/capability.c:377 [inline]
 ns_capable+0x79/0xa0 kernel/capability.c:396
 may_mount fs/namespace.c:1693 [inline]
 can_umount fs/namespace.c:1715 [inline]
 path_umount+0x90/0xa20 fs/namespace.c:1733
 ksys_umount fs/namespace.c:1754 [inline]
 __do_sys_umount fs/namespace.c:1759 [inline]
 __se_sys_umount fs/namespace.c:1757 [inline]
 __x64_sys_umount+0x8b/0xb0 fs/namespace.c:1757
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88801f4fb064 of 4 bytes by task 25806 on cpu 0:
 task_set_jobctl_pending kernel/signal.c:291 [inline]
 do_signal_stop+0x32e/0x6b0 kernel/signal.c:2355
 get_signal+0xa83/0x1510 kernel/signal.c:2718
 arch_do_signal+0x25/0x260 arch/x86/kernel/signal.c:811
 exit_to_user_mode_loop kernel/entry/common.c:161 [inline]
 exit_to_user_mode_prepare+0xde/0x170 kernel/entry/common.c:191
 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 25806 Comm: syz-executor.3 Not tainted 5.10.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/11/29 16:04 upstream aae5ab854e38 a0092f9d .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.