syzbot


KCSAN: data-race in ns_capable / prepare_signal

Status: auto-closed as invalid on 2020/12/23 04:04
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+05448f228949a437c103@syzkaller.appspotmail.com
First crash: 1268d, last: 1253d

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

read-write to 0xffff888021027064 of 4 bytes by task 31395 on cpu 0:
 ns_capable_common kernel/capability.c:377 [inline]
 ns_capable+0x79/0xa0 kernel/capability.c:396
 inet_create+0x235/0x640 net/ipv4/af_inet.c:311
 __sock_create+0x2cc/0x4f0 net/socket.c:1427
 sock_create net/socket.c:1478 [inline]
 __sys_socket+0xb0/0x200 net/socket.c:1520
 __do_sys_socket net/socket.c:1529 [inline]
 __se_sys_socket net/socket.c:1527 [inline]
 __x64_sys_socket+0x3b/0x50 net/socket.c:1527
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888021027064 of 4 bytes by task 31394 on cpu 1:
 sig_task_ignored kernel/signal.c:94 [inline]
 sig_ignored kernel/signal.c:119 [inline]
 prepare_signal+0x891/0xda0 kernel/signal.c:962
 __send_signal+0x64/0x780 kernel/signal.c:1082
 send_signal+0x39f/0x3d0 kernel/signal.c:1242
 __group_send_sig_info kernel/signal.c:1281 [inline]
 do_notify_parent_cldstop+0x231/0x280 kernel/signal.c:2068
 ptrace_stop+0x2aa/0x620 kernel/signal.c:2202
 ptrace_signal kernel/signal.c:2491 [inline]
 get_signal+0xbed/0x1510 kernel/signal.c:2654
 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: 1 PID: 31394 Comm: syz-executor.5 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/11/18 04:03 upstream 111e91a6df50 09323409 .config console log report info ci2-upstream-kcsan-gce
2020/11/03 19:34 upstream b7cbaf59f62f cba33199 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.