KCSAN: data-race in packet_sendmsg / packet

KCSAN: data-race in packet_sendmsg / packet_setsockopt
Status: auto-closed as invalid on 2021/03/04 08:19
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 298d, last: 265d

similar bugs (1):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in packet_sendmsg / packet_setsockopt (2)				1	203d	203d	0/22	auto-closed as invalid on 2021/05/17 10:01

Sample crash report:

==================================================================
BUG: KCSAN: data-race in packet_sendmsg / packet_setsockopt

write to 0xffff888011b16530 of 8 bytes by task 21371 on cpu 0:
 packet_setsockopt+0xfdd/0x2390 net/packet/af_packet.c:3941
 __sys_setsockopt+0x2e8/0x460 net/socket.c:2115
 __do_sys_setsockopt net/socket.c:2126 [inline]
 __se_sys_setsockopt net/socket.c:2123 [inline]
 __x64_sys_setsockopt+0x62/0x70 net/socket.c:2123
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888011b16530 of 8 bytes by task 21376 on cpu 1:
 packet_snd net/packet/af_packet.c:3006 [inline]
 packet_sendmsg+0x2c60/0x3350 net/packet/af_packet.c:3031
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x352/0x4c0 net/socket.c:2345
 ___sys_sendmsg net/socket.c:2399 [inline]
 __sys_sendmmsg+0x335/0x4b0 net/socket.c:2489
 __do_sys_sendmmsg net/socket.c:2518 [inline]
 __se_sys_sendmmsg net/socket.c:2515 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2515
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 21376 Comm: syz-executor.3 Not tainted 5.11.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 21376 Comm: syz-executor.3 Not tainted 5.11.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x116/0x15d lib/dump_stack.c:120
 panic+0x1e7/0x5fa kernel/panic.c:231
 kcsan_report+0x67b/0x680 kernel/kcsan/report.c:634
 kcsan_setup_watchpoint+0x47b/0x4e0 kernel/kcsan/core.c:568
 packet_snd net/packet/af_packet.c:3006 [inline]
 packet_sendmsg+0x2c60/0x3350 net/packet/af_packet.c:3031
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x352/0x4c0 net/socket.c:2345
 ___sys_sendmsg net/socket.c:2399 [inline]
 __sys_sendmmsg+0x335/0x4b0 net/socket.c:2489
 __do_sys_sendmmsg net/socket.c:2518 [inline]
 __se_sys_sendmmsg net/socket.c:2515 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2515
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e219
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fbd6dcd3c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045e219
RDX: 000000000400004e RSI: 0000000020000d00 RDI: 0000000000000005
RBP: 000000000119c070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034
R13: 00007ffeee22846f R14: 00007fbd6dcd49c0 R15: 000000000119c034
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (2):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2021/01/28 08:19	upstream	76c057c84d28	eefc07f2	.config	log	report			info	KCSAN: data-race in packet_sendmsg / packet_setsockopt
ci2-upstream-kcsan-gce	2020/12/26 03:47	upstream	5814bc2d4cc2	821e0b09	.config	log	report			info