syzbot

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BUG: KCSAN: data-race in __cec_s_phys_addr / cec_thread_func

read to 0xffff888128a4dbf0 of 1 bytes by task 3085 on cpu 1:
 cec_thread_func+0x7ea/0x930 drivers/media/cec/cec-adap.c:477
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

write to 0xffff888128a4dbf0 of 1 bytes by task 9963 on cpu 0:
 __cec_s_phys_addr+0x234/0x5d0 drivers/media/cec/cec-adap.c:1558
 cec_s_phys_addr drivers/media/cec/cec-adap.c:1597 [inline]
 cec_s_phys_addr+0x67/0xa0 drivers/media/cec/cec-adap.c:1591
 vidioc_s_edid+0x403/0x610 drivers/media/platform/vivid/vivid-vid-cap.c:1795
 v4l_stub_s_edid+0x40/0x60 drivers/media/v4l2-core/v4l2-ioctl.c:2668
 __video_do_ioctl+0x3e1/0x720 drivers/media/v4l2-core/v4l2-ioctl.c:2910
 video_usercopy+0x418/0xa40 drivers/media/v4l2-core/v4l2-ioctl.c:3092
 video_ioctl2+0x36/0x49 drivers/media/v4l2-core/v4l2-ioctl.c:3136
 v4l2_ioctl+0xe1/0x110 drivers/media/v4l2-core/v4l2-dev.c:360
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x991/0xc60 fs/ioctl.c:696
 ksys_ioctl+0xbd/0xe0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x4c/0x60 fs/ioctl.c:718
 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: 9963 Comm: syz-executor.5 Not tainted 5.4.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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