Signed-off-by: Biancaa Ramesh <biancaa2210329@ssn.edu.in>
[PATCH] media: cx18: fix potential double free in cx18_stream_alloc

The function cx18_stream_alloc() may free buf->buf and buf multiple times
if dma_mapping_error() occurs. This patch:

- Adds checks before kfree() to avoid double free
- Sets pointers to NULL after free to make accidental double free less likely
- Improves overall memory safety and robustness in error paths
---
 drivers/media/pci/cx18/cx18-queue.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/media/pci/cx18/cx18-queue.c b/drivers/media/pci/cx18/cx18-queue.c
index eeb5513b1d52..025ba4e6e4be 100644
--- a/drivers/media/pci/cx18/cx18-queue.c
+++ b/drivers/media/pci/cx18/cx18-queue.c
@@ -383,9 +383,16 @@ int cx18_stream_alloc(struct cx18_stream *s)
 						 buf->buf, s->buf_size,
 						 s->dma);
 		if (dma_mapping_error(&s->cx->pci_dev->dev, buf->dma_handle)) {
-			kfree(buf->buf);
+			if (buf) {
+        		if (buf->buf){
+            	kfree(buf->buf);
+				buf->buf =NULL;
+				}
+        		kfree(buf);
+				buf=NULL;
+    		}
 			kfree(mdl);
-			kfree(buf);
+			//makes accidental double free less possible
 			break;
 		}
 
-- 
2.43.0


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