syzbot

==================================================================
BUG: KCSAN: data-race in unix_dgram_connect / unix_dgram_poll

write to 0xffff888107739230 of 4 bytes by task 13706 on cpu 1:
 unix_dgram_disconnected net/unix/af_unix.c:486 [inline]
 unix_dgram_connect+0x754/0x820 net/unix/af_unix.c:1191
 __sys_connect_file net/socket.c:1837 [inline]
 __sys_connect+0x245/0x280 net/socket.c:1854
 __do_sys_connect net/socket.c:1864 [inline]
 __se_sys_connect net/socket.c:1861 [inline]
 __x64_sys_connect+0x3d/0x50 net/socket.c:1861
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888107739230 of 4 bytes by task 13698 on cpu 0:
 unix_dgram_poll+0x6e/0x3b0 net/unix/af_unix.c:2693
 sock_poll+0x23e/0x260 net/socket.c:1246
 vfs_poll include/linux/poll.h:90 [inline]
 ep_item_poll fs/eventpoll.c:840 [inline]
 ep_send_events fs/eventpoll.c:1677 [inline]
 ep_poll fs/eventpoll.c:1792 [inline]
 do_epoll_wait+0x6ad/0xf00 fs/eventpoll.c:2220
 __do_sys_epoll_wait fs/eventpoll.c:2232 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2227 [inline]
 __x64_sys_epoll_wait+0xf6/0x120 fs/eventpoll.c:2227
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13698 Comm: syz-executor.5 Not tainted 5.12.0-rc1-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: 0 PID: 13698 Comm: syz-executor.5 Not tainted 5.12.0-rc1-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+0x137/0x19d lib/dump_stack.c:120
 panic+0x1e7/0x5fa kernel/panic.c:231
 kcsan_report+0x67b/0x680 kernel/kcsan/report.c:634
 kcsan_setup_watchpoint+0x40b/0x470 kernel/kcsan/core.c:564
 unix_dgram_poll+0x6e/0x3b0 net/unix/af_unix.c:2693
 sock_poll+0x23e/0x260 net/socket.c:1246
 vfs_poll include/linux/poll.h:90 [inline]
 ep_item_poll fs/eventpoll.c:840 [inline]
 ep_send_events fs/eventpoll.c:1677 [inline]
 ep_poll fs/eventpoll.c:1792 [inline]
 do_epoll_wait+0x6ad/0xf00 fs/eventpoll.c:2220
 __do_sys_epoll_wait fs/eventpoll.c:2232 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2227 [inline]
 __x64_sys_epoll_wait+0xf6/0x120 fs/eventpoll.c:2227
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x465ef9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f050780f188 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465ef9
RDX: 0000000000000001 RSI: 0000000020000040 RDI: 0000000000000005
RBP: 00000000004bfa34 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000400 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffcf94964af R14: 00007f050780f300 R15: 0000000000022000
Kernel Offset: disabled
Rebooting in 86400 seconds..