[PATCH] kernel memory safety check in a block

[PATCH] kernel memory safety check in a block

[Biancaa Ramesh]

Signed-off-by: Biancaa Ramesh <biancaa2210329@ssn.edu.in>
---
 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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Re: [PATCH] media: cx18: kernel memory safety check in a block

[Markus Elfring]

…
> ---
>  drivers/media/pci/cx18/cx18-queue.c | 11 +++++++++--
…

Thanks for your try to improve the implementation of the function “cx18_stream_alloc”.
https://elixir.bootlin.com/linux/v6.18-rc2/source/drivers/media/pci/cx18/cx18-queue.c#L332-L408

I miss some information so far.

1. Helpful change description
   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.18-rc2#n45

2. Subsystem specification
   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.18-rc2#n646
   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/log/drivers/media/pci/cx18/cx18-queue.c

3. More appropriate recipient selection
   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.18-rc2#n231


…
> -- 
> ::DISCLAIMER::
…
> The 
> contents of this e-mail and any attachment(s) are confidential and
…

Such hints are probably misplaced for communication by the means of public mailing lists.

See also once more:
https://subspace.kernel.org/etiquette.html#do-not-include-confidentiality-disclaimers

Regards,
Markus