syzbot

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BUG: KCSAN: data-race in isotp_sendmsg / isotp_sendmsg

write to 0xffff88813da324b4 of 4 bytes by task 10319 on cpu 0:
 isotp_sendmsg+0x3b1/0xc70 net/can/isotp.c:1123
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 ____sys_sendmsg+0x375/0x4c0 net/socket.c:2503
 ___sys_sendmsg net/socket.c:2557 [inline]
 __sys_sendmsg+0x1e3/0x270 net/socket.c:2586
 __do_sys_sendmsg net/socket.c:2595 [inline]
 __se_sys_sendmsg net/socket.c:2593 [inline]
 __x64_sys_sendmsg+0x46/0x50 net/socket.c:2593
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88813da324b4 of 4 bytes by task 10323 on cpu 1:
 isotp_sendmsg+0x213/0xc70 net/can/isotp.c:963
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 ____sys_sendmsg+0x375/0x4c0 net/socket.c:2503
 ___sys_sendmsg net/socket.c:2557 [inline]
 __sys_sendmsg+0x1e3/0x270 net/socket.c:2586
 __do_sys_sendmsg net/socket.c:2595 [inline]
 __se_sys_sendmsg net/socket.c:2593 [inline]
 __x64_sys_sendmsg+0x46/0x50 net/socket.c:2593
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00000001 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10323 Comm: syz-executor.5 Not tainted 6.4.0-rc4-syzkaller-00204-gc43a6ff9f93f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
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