syzbot

vim2m vim2m.0: vidioc_s_fmt queue busy
==================================================================
BUG: KCSAN: data-race in vidioc_s_fmt / vim2m_queue_setup

write to 0xffff8880969bba04 of 4 bytes by task 32314 on cpu 1:
 vidioc_s_fmt+0x31c/0x460 drivers/media/test-drivers/vim2m.c:863
 vidioc_s_fmt_vid_out+0x66/0x120 drivers/media/test-drivers/vim2m.c:901
 v4l_s_fmt+0x2a9/0x6f0 drivers/media/v4l2-core/v4l2-ioctl.c:1700
 __video_do_ioctl+0x65b/0x870 drivers/media/v4l2-core/v4l2-ioctl.c:2987
 video_usercopy+0x6d8/0xfe0 drivers/media/v4l2-core/v4l2-ioctl.c:3303
 video_ioctl2+0x25/0x30 drivers/media/v4l2-core/v4l2-ioctl.c:3340
 v4l2_ioctl+0xc2/0xd0 drivers/media/v4l2-core/v4l2-dev.c:360
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880969bba04 of 4 bytes by task 32310 on cpu 0:
 vim2m_queue_setup+0x98/0x260 drivers/media/test-drivers/vim2m.c:1000
 vb2_core_reqbufs+0x62b/0x9d0 drivers/media/common/videobuf2/videobuf2-core.c:812
 vb2_reqbufs+0x28b/0x2a0 drivers/media/common/videobuf2/videobuf2-v4l2.c:739
 v4l2_m2m_reqbufs drivers/media/v4l2-core/v4l2-mem2mem.c:538 [inline]
 v4l2_m2m_ioctl_reqbufs+0xb7/0x120 drivers/media/v4l2-core/v4l2-mem2mem.c:1285
 v4l_reqbufs+0x64/0x80 drivers/media/v4l2-core/v4l2-ioctl.c:2045
 __video_do_ioctl+0x65b/0x870 drivers/media/v4l2-core/v4l2-ioctl.c:2987
 video_usercopy+0x6d8/0xfe0 drivers/media/v4l2-core/v4l2-ioctl.c:3303
 video_ioctl2+0x25/0x30 drivers/media/v4l2-core/v4l2-ioctl.c:3340
 v4l2_ioctl+0xc2/0xd0 drivers/media/v4l2-core/v4l2-dev.c:360
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 32310 Comm: syz-executor.0 Not tainted 5.9.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================