syzbot

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BUG: KCSAN: data-race in addr_handler / cma_check_port

write to 0xffff88809fa40a1c of 4 bytes by task 21 on cpu 1:
 cma_comp_exch drivers/infiniband/core/cma.c:426 [inline]
 addr_handler+0x9f/0x2b0 drivers/infiniband/core/cma.c:3141
 process_one_req+0x22f/0x300 drivers/infiniband/core/addr.c:645
 process_one_work+0x3e1/0x9a0 kernel/workqueue.c:2269
 worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
 kthread+0x20d/0x230 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

read to 0xffff88809fa40a1c of 4 bytes by task 11997 on cpu 0:
 cma_check_port+0xbd/0x700 drivers/infiniband/core/cma.c:3506
 cma_use_port drivers/infiniband/core/cma.c:3541 [inline]
 cma_get_port drivers/infiniband/core/cma.c:3623 [inline]
 rdma_bind_addr+0x1639/0x1910 drivers/infiniband/core/cma.c:3741
 cma_bind_addr drivers/infiniband/core/cma.c:3252 [inline]
 rdma_resolve_addr+0x486/0x1240 drivers/infiniband/core/cma.c:3264
 ucma_resolve_ip+0x121/0x1b0 drivers/infiniband/core/ucma.c:722
 ucma_write+0x229/0x250 drivers/infiniband/core/ucma.c:1764
 vfs_write+0x1d6/0x690 fs/read_write.c:576
 ksys_write+0xce/0x180 fs/read_write.c:631
 __do_sys_write fs/read_write.c:643 [inline]
 __se_sys_write fs/read_write.c:640 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:640
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 11997 Comm: syz-executor.4 Not tainted 5.8.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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