syzbot

==================================================================
BUG: KCSAN: data-race in rcvbuf_limit / tipc_group_join

read to 0xffff8880a2405d0c of 4 bytes by task 7 on cpu 0:
 rcvbuf_limit+0xba/0x1b0 net/tipc/socket.c:2122
 tipc_sk_enqueue net/tipc/socket.c:2262 [inline]
 tipc_sk_rcv+0x3f9/0xfc0 net/tipc/socket.c:2305
 tipc_topsrv_kern_evt net/tipc/topsrv.c:613 [inline]
 tipc_conn_send_to_sock+0x4f7/0x580 net/tipc/topsrv.c:284
 tipc_conn_send_work+0x4b/0x70 net/tipc/topsrv.c:304
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

write to 0xffff8880a2405d0c of 4 bytes by task 675 on cpu 1:
 tipc_group_join+0x10e/0x150 net/tipc/group.c:208
 tipc_sk_join net/tipc/socket.c:2910 [inline]
 tipc_setsockopt+0x336/0x7a0 net/tipc/socket.c:3005
 __sys_setsockopt+0x1ce/0x370 net/socket.c:2084
 __do_sys_setsockopt net/socket.c:2100 [inline]
 __se_sys_setsockopt net/socket.c:2097 [inline]
 __x64_sys_setsockopt+0x70/0x90 net/socket.c:2097
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 675 Comm: syz-executor.3 Not tainted 5.4.0-rc3+ #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: 675 Comm: syz-executor.3 Not tainted 5.4.0-rc3+ #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+0xf5/0x159 lib/dump_stack.c:113
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0x10 kernel/kcsan/report.c:302
 __kcsan_setup_watchpoint+0x32e/0x4a0 kernel/kcsan/core.c:411
 __tsan_write4 kernel/kcsan/kcsan.c:35 [inline]
 __tsan_write4+0x32/0x40 kernel/kcsan/kcsan.c:35
 tipc_group_join+0x10e/0x150 net/tipc/group.c:208
 tipc_sk_join net/tipc/socket.c:2910 [inline]
 tipc_setsockopt+0x336/0x7a0 net/tipc/socket.c:3005
 __sys_setsockopt+0x1ce/0x370 net/socket.c:2084
 __do_sys_setsockopt net/socket.c:2100 [inline]
 __se_sys_setsockopt net/socket.c:2097 [inline]
 __x64_sys_setsockopt+0x70/0x90 net/socket.c:2097
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x459f49
Code: ad 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ff008700c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459f49
RDX: 0000000000000087 RSI: 000000000000010f RDI: 0000000000000004
RBP: 000000000075bf20 R08: 000000000000fde1 R09: 0000000000000000
R10: 0000000020000080 R11: 0000000000000246 R12: 00007ff0087016d4
R13: 00000000004c9053 R14: 00000000004e0780 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..