syzbot


KCSAN: data-race in raw_recvmsg / sock_valbool_flag

Status: auto-closed as invalid on 2022/07/10 10:01
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 180d, last: 180d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in raw_recvmsg / sock_valbool_flag

write to 0xffff88816e4acc60 of 8 bytes by task 13666 on cpu 0:
 instrument_write include/linux/instrumented.h:42 [inline]
 __set_bit include/asm-generic/bitops/instrumented-non-atomic.h:27 [inline]
 sock_set_flag include/net/sock.h:919 [inline]
 sock_valbool_flag+0x41/0x70 include/net/sock.h:931
 sock_setsockopt+0x17c9/0x1a40
 __sys_setsockopt+0x242/0x2b0 net/socket.c:2255
 __do_sys_setsockopt net/socket.c:2270 [inline]
 __se_sys_setsockopt net/socket.c:2267 [inline]
 __x64_sys_setsockopt+0x62/0x70 net/socket.c:2267
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

read to 0xffff88816e4acc60 of 8 bytes by task 13669 on cpu 1:
 sock_recv_cmsgs include/net/sock.h:2681 [inline]
 raw_recvmsg+0x19d/0x430 net/ipv4/raw.c:786
 inet_recvmsg+0x9e/0x210 net/ipv4/af_inet.c:850
 ____sys_recvmsg+0x162/0x2f0
 ___sys_recvmsg net/socket.c:2753 [inline]
 do_recvmmsg+0x53a/0xa30 net/socket.c:2847
 __sys_recvmmsg net/socket.c:2926 [inline]
 __do_sys_recvmmsg net/socket.c:2949 [inline]
 __se_sys_recvmmsg net/socket.c:2942 [inline]
 __x64_sys_recvmmsg+0xde/0x160 net/socket.c:2942
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

value changed: 0x0000000000080100 -> 0x0000000000081980

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13669 Comm: syz-executor.2 Not tainted 5.18.0-syzkaller-13818-gd0e60d46bc03-dirty #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 2022/06/05 10:01 upstream d0e60d46bc03 c8857892 .config log report info KCSAN: data-race in raw_recvmsg / sock_valbool_flag
* Struck through repros no longer work on HEAD.