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Commit 5fae054c authored by Dan Carpenter's avatar Dan Carpenter Committed by Greg Kroah-Hartman
Browse files

goldfish: locking bugs in goldfish_pipe_read_write() 



We recently messed up the error handling here.  We can return with the
pipe->lock held or sometimes we unlock twice by mistake.

Fixes: 2f3be882 ('goldfish_pipe: Pin pages to memory while copying and other cleanups')
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d40a0946

drivers/platform/goldfish/goldfish_pipe.c

+8 −14
Original line number Diff line number Diff line
@@ -313,7 +313,7 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer, 
				     !is_write, 0, &page, NULL);

		up_read(&current->mm->mmap_sem);

		if (ret < 0)

			return ret;

			break;



		if (dev->version) {

			/* Device version 1 or newer (qemu-android) expects the
@@ -400,22 +400,16 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer, 
		while (test_bit(wakeBit, &pipe->flags)) {

			if (wait_event_interruptible(

					pipe->wake_queue,

					!test_bit(wakeBit, &pipe->flags))) {

				ret = -ERESTARTSYS;

				break;

			}

					!test_bit(wakeBit, &pipe->flags)))

				return -ERESTARTSYS;



			if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags)) {

				ret = -EIO;

				break;

			}

			if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags))

				return -EIO;

		}



		/* Try to re-acquire the lock */

		if (mutex_lock_interruptible(&pipe->lock)) {

			ret = -ERESTARTSYS;

			break;

		}

		if (mutex_lock_interruptible(&pipe->lock))

			return -ERESTARTSYS;

	}

	mutex_unlock(&pipe->lock);