Patch "dma-buf/dma-resv: Stop leaking on krealloc() failure" has been added to the 6.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    dma-buf/dma-resv: Stop leaking on krealloc() failure

to the 6.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     dma-buf-dma-resv-stop-leaking-on-krealloc-failure.patch
and it can be found in the queue-6.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From 05abb3be91d8788328231ee02973ab3d47f5e3d2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Thu, 13 Jul 2023 22:47:45 +0300
Subject: dma-buf/dma-resv: Stop leaking on krealloc() failure
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

commit 05abb3be91d8788328231ee02973ab3d47f5e3d2 upstream.

Currently dma_resv_get_fences() will leak the previously
allocated array if the fence iteration got restarted and
the krealloc_array() fails.

Free the old array by hand, and make sure we still clear
the returned *fences so the caller won't end up accessing
freed memory. Some (but not all) of the callers of
dma_resv_get_fences() seem to still trawl through the
array even when dma_resv_get_fences() failed. And let's
zero out *num_fences as well for good measure.

Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Christian König <christian.koenig@amd.com>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Fixes: d3c80698c9f5 ("dma-buf: use new iterator in dma_resv_get_fences v3")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20230713194745.1751-1-ville.syrjala@linux.intel.com
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/dma-buf/dma-resv.c |   13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -571,6 +571,7 @@ int dma_resv_get_fences(struct dma_resv
 	dma_resv_for_each_fence_unlocked(&cursor, fence) {
 
 		if (dma_resv_iter_is_restarted(&cursor)) {
+			struct dma_fence **new_fences;
 			unsigned int count;
 
 			while (*num_fences)
@@ -579,13 +580,17 @@ int dma_resv_get_fences(struct dma_resv
 			count = cursor.num_fences + 1;
 
 			/* Eventually re-allocate the array */
-			*fences = krealloc_array(*fences, count,
-						 sizeof(void *),
-						 GFP_KERNEL);
-			if (count && !*fences) {
+			new_fences = krealloc_array(*fences, count,
+						    sizeof(void *),
+						    GFP_KERNEL);
+			if (count && !new_fences) {
+				kfree(*fences);
+				*fences = NULL;
+				*num_fences = 0;
 				dma_resv_iter_end(&cursor);
 				return -ENOMEM;
 			}
+			*fences = new_fences;
 		}
 
 		(*fences)[(*num_fences)++] = dma_fence_get(fence);


Patches currently in stable-queue which might be from ville.syrjala@linux.intel.com are

queue-6.4/dma-buf-dma-resv-stop-leaking-on-krealloc-failure.patch