media: imon: fix a race condition in send_packet()

The function send_packet() has a race condition as follows:

func send_packet()
{
    // do work
    call usb_submit_urb()
    mutex_unlock()
    wait_for_event_interruptible()  <-- lock gone
    mutex_lock()
}

func vfd_write()
{
    mutex_lock()
    call send_packet()  <- prev call is not completed
    mutex_unlock()
}

When the mutex is unlocked and the function send_packet() waits for the
call to complete, vfd_write() can start another call, which leads to the
"URB submitted while active" warning in usb_submit_urb().
Fix this by removing the mutex_unlock() call in send_packet() and using
mutex_lock_interruptible().

Link: https://syzkaller.appspot.com/bug?id=e378e6a51fbe6c5cc43e34f131cc9a315ef0337e

Fixes: 21677cfc562a ("V4L/DVB: ir-core: add imon driver")
Reported-by: [email protected]
Signed-off-by: Gautam Menghani <[email protected]>
Signed-off-by: Sean Young <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>

0 files changed, 0 insertions, 0 deletions