syzbot

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

write to 0xffff8880a4346cd8 of 2 bytes by task 15829 on cpu 0:
 packet_do_bind+0x1e6/0x6f0 net/packet/af_packet.c:3135
 packet_bind+0xc3/0xd0 net/packet/af_packet.c:3219
 __sys_bind+0x1fd/0x2a0 net/socket.c:1656
 __do_sys_bind net/socket.c:1667 [inline]
 __se_sys_bind net/socket.c:1665 [inline]
 __x64_sys_bind+0x3d/0x50 net/socket.c:1665
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880a4346cd8 of 2 bytes by task 15834 on cpu 1:
 packet_snd net/packet/af_packet.c:2863 [inline]
 packet_sendmsg+0x2ac/0x3400 net/packet/af_packet.c:3004
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 __sys_sendto+0x2ad/0x380 net/socket.c:1994
 __do_sys_sendto net/socket.c:2006 [inline]
 __se_sys_sendto net/socket.c:2002 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:2002
 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: 15834 Comm: syz-executor.1 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 15834 Comm: syz-executor.1 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x10f/0x19d lib/dump_stack.c:118
 panic+0x207/0x64a kernel/panic.c:231
 kcsan_report+0x684/0x690 kernel/kcsan/report.c:630
 kcsan_setup_watchpoint+0x41e/0x4a0 kernel/kcsan/core.c:540
 packet_snd net/packet/af_packet.c:2863 [inline]
 packet_sendmsg+0x2ac/0x3400 net/packet/af_packet.c:3004
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 __sys_sendto+0x2ad/0x380 net/socket.c:1994
 __do_sys_sendto net/socket.c:2006 [inline]
 __se_sys_sendto net/socket.c:2002 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:2002
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45ce69
Code: 2d b6 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 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fd62ec79c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000000000002c3c0 RCX: 000000000045ce69
RDX: 0000000000003287 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 000000000118c018 R08: 0000000000000000 R09: 00000000000002ff
R10: 0000000004000002 R11: 0000000000000246 R12: 000000000118bfcc
R13: 00007ffd78f2dcaf R14: 00007fd62ec7a9c0 R15: 000000000118bfcc
Kernel Offset: disabled
Rebooting in 86400 seconds..