[PATCH] V4L: Fix read() bugs in bttv driver

Fix read() bugs in bttv driver.

Signed-off-by: Nickolay V. Shmyrev <nshmyrev@yandex.ru>
Signed-off-by: Michael H. Schimek <mschimek@gmx.at>
Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/media/video/bttv-driver.c

@@ -2952,6 +2952,8 @@ static unsigned int bttv_poll(struct file *file, poll_table *wait)
 			fh->cap.read_buf->memory = V4L2_MEMORY_USERPTR;
 			field = videobuf_next_field(&fh->cap);
 			if (0 != fh->cap.ops->buf_prepare(&fh->cap,fh->cap.read_buf,field)) {
+				kfree (fh->cap.read_buf);
+				fh->cap.read_buf = NULL;
 				up(&fh->cap.lock);
 				return POLLERR;
 			}

drivers/media/video/video-buf.c

@@ -753,10 +753,9 @@ videobuf_read_zerocopy(struct videobuf_queue *q, char __user *data,
 	int retval;
 
 	/* setup stuff */
-	retval = -ENOMEM;
 	q->read_buf = videobuf_alloc(q->msize);
 	if (NULL == q->read_buf)
-		goto done;
+		return -ENOMEM;
 
 	q->read_buf->memory = V4L2_MEMORY_USERPTR;
 	q->read_buf->baddr  = (unsigned long)data;
@@ -819,8 +818,11 @@ ssize_t videobuf_read_one(struct videobuf_queue *q,
 		q->read_buf->memory = V4L2_MEMORY_USERPTR;
 		field = videobuf_next_field(q);
 		retval = q->ops->buf_prepare(q,q->read_buf,field);
-		if (0 != retval)
+		if (0 != retval) {
+			kfree (q->read_buf);
+			q->read_buf = NULL;
 			goto done;
+		}
 		spin_lock_irqsave(q->irqlock,flags);
 		q->ops->buf_queue(q,q->read_buf);
 		spin_unlock_irqrestore(q->irqlock,flags);