v4l2: Fail v4l2_alloc_buffers() when buffers are already allocated

Allocating buffers allocates resources that must be explicitly freed.
Calling v4l2_alloc_buffers() a second time without freeing the buffers
in between causes memory leaks and must not be allowed.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/v4l2.c b/v4l2.c
index 3baf55b..8d5e847 100644
--- a/v4l2.c
+++ b/v4l2.c
@@ -510,6 +510,9 @@ int v4l2_alloc_buffers(struct v4l2_device *dev, enum v4l2_memory memtype,
 	unsigned int i;
 	int ret;
 
+	if (dev->nbufs != 0)
+		return -EBUSY;
+
 	/* Request the buffers from the driver. */
 	memset(&rb, 0, sizeof rb);
 	rb.count = nbufs;