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.sy... 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);