syzbot

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BUG: KCSAN: data-race in can_send / can_send

write to 0xffff8880ad74d8f0 of 8 bytes by interrupt on cpu 1:
 can_send+0x345/0x550 net/can/af_can.c:291
 j1939_send_one+0x17e/0x1e0 net/can/j1939/main.c:340
 j1939_tp_tx_dat net/can/j1939/transport.c:615 [inline]
 j1939_session_tx_dat net/can/j1939/transport.c:791 [inline]
 j1939_xtp_txnext_transmiter net/can/j1939/transport.c:847 [inline]
 j1939_tp_txtimer+0x48f/0x1280 net/can/j1939/transport.c:1095
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x271/0x600 kernel/time/hrtimer.c:1579
 hrtimer_run_softirq+0xeb/0x120 kernel/time/hrtimer.c:1596
 __do_softirq+0x118/0x34a kernel/softirq.c:292
 run_ksoftirqd+0x41/0x60 kernel/softirq.c:603
 smpboot_thread_fn+0x374/0x4a0 kernel/smpboot.c:165
 kthread+0x1cb/0x1f0 kernel/kthread.c:255
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffff8880ad74d8f0 of 8 bytes by interrupt on cpu 0:
 can_send+0x335/0x550 net/can/af_can.c:291
 j1939_send_one+0x17e/0x1e0 net/can/j1939/main.c:340
 j1939_tp_tx_dat net/can/j1939/transport.c:615 [inline]
 j1939_session_tx_dat net/can/j1939/transport.c:791 [inline]
 j1939_xtp_txnext_transmiter net/can/j1939/transport.c:847 [inline]
 j1939_tp_txtimer+0x48f/0x1280 net/can/j1939/transport.c:1095
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x271/0x600 kernel/time/hrtimer.c:1579
 hrtimer_run_softirq+0xeb/0x120 kernel/time/hrtimer.c:1596
 __do_softirq+0x118/0x34a kernel/softirq.c:292
 run_ksoftirqd+0x41/0x60 kernel/softirq.c:603
 smpboot_thread_fn+0x374/0x4a0 kernel/smpboot.c:165
 kthread+0x1cb/0x1f0 kernel/kthread.c:255
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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