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BUG: KCSAN: data-race in kcm_rcv_strparser / kcm_rfree

write to 0xffff8881453977c8 of 1 bytes by task 28248 on cpu 0:
 reserve_rx_kcm net/kcm/kcmsock.c:283 [inline]
 kcm_rcv_strparser+0x26e/0x3d0 net/kcm/kcmsock.c:363
 __strp_recv+0x699/0xf20 net/strparser/strparser.c:301
 strp_recv+0x6d/0x80 net/strparser/strparser.c:335
 tcp_read_sock+0x2cb/0xb20 net/ipv4/tcp.c:1674
 strp_read_sock net/strparser/strparser.c:358 [inline]
 do_strp_work net/strparser/strparser.c:406 [inline]
 strp_work+0xe8/0x180 net/strparser/strparser.c:415
 process_one_work+0x3f6/0x960 kernel/workqueue.c:2307
 worker_thread+0x616/0xa70 kernel/workqueue.c:2454
 kthread+0x1bf/0x1e0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30

read to 0xffff8881453977c8 of 1 bytes by task 7975 on cpu 1:
 kcm_rfree+0xfa/0x200 net/kcm/kcmsock.c:181
 skb_release_head_state+0xb3/0x1a0 net/core/skbuff.c:729
 skb_release_all net/core/skbuff.c:740 [inline]
 __kfree_skb+0x14/0x150 net/core/skbuff.c:756
 kfree_skb_reason+0x52/0x170 net/core/skbuff.c:776
 kfree_skb include/linux/skbuff.h:1114 [inline]
 kcm_recvmsg+0x247/0x2e0 net/kcm/kcmsock.c:1161
 ____sys_recvmsg+0x16c/0x320
 ___sys_recvmsg net/socket.c:2674 [inline]
 do_recvmmsg+0x3f5/0xae0 net/socket.c:2768
 __sys_recvmmsg net/socket.c:2847 [inline]
 __do_sys_recvmmsg net/socket.c:2870 [inline]
 __se_sys_recvmmsg net/socket.c:2863 [inline]
 __x64_sys_recvmmsg+0xde/0x160 net/socket.c:2863
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x01 -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7975 Comm: syz-executor.5 Not tainted 5.17.0-rc2-syzkaller-00039-g9f7fb8de5d9b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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