==================================================================
BUG: KCSAN: data-race in p9_poll_workfn / p9_write_work

read to 0xffff888101f16e94 of 4 bytes by task 7553 on cpu 0:
 p9_poll_mux net/9p/trans_fd.c:637 [inline]
 p9_poll_workfn+0xb9/0x350 net/9p/trans_fd.c:1122
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

write to 0xffff888101f16e94 of 4 bytes by task 17 on cpu 1:
 p9_write_work+0x3ea/0x6d0 net/9p/trans_fd.c:465
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17 Comm: kworker/1:0 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events p9_write_work
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 17 Comm: kworker/1:0 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events p9_write_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x11d/0x181 lib/dump_stack.c:118
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0xd kernel/kcsan/report.c:315
 kcsan_setup_watchpoint+0x3fe/0x460 kernel/kcsan/core.c:423
 check_access kernel/kcsan/core.c:466 [inline]
 __tsan_write4 kernel/kcsan/core.c:595 [inline]
 __tsan_unaligned_write4+0xc4/0x100 kernel/kcsan/core.c:595
 p9_write_work+0x3ea/0x6d0 net/9p/trans_fd.c:465
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..