syzbot

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BUG: KCSAN: data-race in af_alg_sendmsg / af_alg_wait_for_data

write to 0xffff8880a6d426d4 of 1 bytes by task 9644 on cpu 1:
 af_alg_sendmsg+0x9c3/0xbe0 crypto/af_alg.c:944
 skcipher_sendmsg crypto/algif_skcipher.c:47 [inline]
 skcipher_sendmsg_nokey crypto/algif_skcipher.c:255 [inline]
 skcipher_sendmsg_nokey+0x9b/0xc0 crypto/algif_skcipher.c:246
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:657
 ___sys_sendmsg+0x59d/0x5d0 net/socket.c:2311
 __sys_sendmsg+0xa0/0x160 net/socket.c:2356
 __do_sys_sendmsg net/socket.c:2365 [inline]
 __se_sys_sendmsg net/socket.c:2363 [inline]
 __x64_sys_sendmsg+0x51/0x70 net/socket.c:2363
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880a6d426d4 of 1 bytes by task 9632 on cpu 0:
 af_alg_wait_for_data+0x1f3/0x2e0 crypto/af_alg.c:759
 _skcipher_recvmsg crypto/algif_skcipher.c:65 [inline]
 skcipher_recvmsg+0x522/0x800 crypto/algif_skcipher.c:161
 skcipher_recvmsg_nokey+0x5e/0x80 crypto/algif_skcipher.c:279
 sock_recvmsg_nosec net/socket.c:871 [inline]
 sock_recvmsg net/socket.c:889 [inline]
 sock_recvmsg+0x92/0xb0 net/socket.c:885
 __sys_recvfrom+0x1ae/0x2d0 net/socket.c:2009
 __do_sys_recvfrom net/socket.c:2027 [inline]
 __se_sys_recvfrom net/socket.c:2023 [inline]
 __x64_sys_recvfrom+0x89/0xb0 net/socket.c:2023
 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: 0 PID: 9632 Comm: syz-executor.5 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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