FAILED: patch "[PATCH] media: cx18: Add missing check after DMA map" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 23b53639a793477326fd57ed103823a8ab63084f
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025101641-clutter-scruffy-a000@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 23b53639a793477326fd57ed103823a8ab63084f Mon Sep 17 00:00:00 2001
From: Thomas Fourier <fourier.thomas@gmail.com>
Date: Wed, 9 Jul 2025 13:35:40 +0200
Subject: [PATCH] media: cx18: Add missing check after DMA map

The DMA map functions can fail and should be tested for errors.
If the mapping fails, dealloc buffers, and return.

Fixes: 1c1e45d17b66 ("V4L/DVB (7786): cx18: new driver for the Conexant CX23418 MPEG encoder chip")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

diff --git a/drivers/media/pci/cx18/cx18-queue.c b/drivers/media/pci/cx18/cx18-queue.c
index 013694bfcb1c..7cbb2d586932 100644
--- a/drivers/media/pci/cx18/cx18-queue.c
+++ b/drivers/media/pci/cx18/cx18-queue.c
@@ -379,15 +379,22 @@ int cx18_stream_alloc(struct cx18_stream *s)
 			break;
 		}
 
+		buf->dma_handle = dma_map_single(&s->cx->pci_dev->dev,
+						 buf->buf, s->buf_size,
+						 s->dma);
+		if (dma_mapping_error(&s->cx->pci_dev->dev, buf->dma_handle)) {
+			kfree(buf->buf);
+			kfree(mdl);
+			kfree(buf);
+			break;
+		}
+
 		INIT_LIST_HEAD(&mdl->list);
 		INIT_LIST_HEAD(&mdl->buf_list);
 		mdl->id = s->mdl_base_idx; /* a somewhat safe value */
 		cx18_enqueue(s, mdl, &s->q_idle);
 
 		INIT_LIST_HEAD(&buf->list);
-		buf->dma_handle = dma_map_single(&s->cx->pci_dev->dev,
-						 buf->buf, s->buf_size,
-						 s->dma);
 		cx18_buf_sync_for_cpu(s, buf);
 		list_add_tail(&buf->list, &s->buf_pool);
 	}