syzbot

==================================================================
BUG: KCSAN: data-race in rds_cong_map_updated / rds_recvmsg

write to 0xffff888084e47168 of 8 bytes by task 908 on cpu 1:
 rds_cong_map_updated+0x28a/0x320 net/rds/cong.c:271
 rds_loop_xmit+0x13c/0x180 net/rds/loop.c:85
 rds_send_xmit+0xbf5/0x1600 net/rds/send.c:367
 rds_send_worker+0x9d/0x250 net/rds/threads.c:200
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2264
 worker_thread+0xa0/0x800 kernel/workqueue.c:2410
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffff888084e47168 of 8 bytes by task 7869 on cpu 0:
 rds_recvmsg+0x6c8/0xc00 net/rds/recv.c:673
 sock_recvmsg_nosec net/socket.c:873 [inline]
 ____sys_recvmsg+0x387/0x3a0 net/socket.c:2551
 ___sys_recvmsg+0xb2/0x100 net/socket.c:2595
 do_recvmmsg+0x19a/0x5c0 net/socket.c:2693
 __sys_recvmmsg+0x1ef/0x200 net/socket.c:2772
 __do_sys_recvmmsg net/socket.c:2795 [inline]
 __se_sys_recvmmsg net/socket.c:2788 [inline]
 __x64_sys_recvmmsg+0x89/0xb0 net/socket.c:2788
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7869 Comm: syz-executor.3 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================