drm/amd/amdkfd: Fix a resource leak in svm_range_validate_and_map()

Analysis of code by Coverity, a static code analyser, has identified
a resource leak in the symbol hmm_range. This leak occurs when one of
the prior steps before it is released encounters an error.

Signed-off-by: Ramesh Errabolu <Ramesh.Errabolu@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 4e5851b..b1ec7ef 100644 (file)
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -1670,7 +1670,7 @@ static int svm_range_validate_and_map(struct mm_struct *mm,
        start = map_start << PAGE_SHIFT;
        end = (map_last + 1) << PAGE_SHIFT;
        for (addr = start; !r && addr < end; ) {
-               struct hmm_range *hmm_range;
+               struct hmm_range *hmm_range = NULL;
                unsigned long map_start_vma;
                unsigned long map_last_vma;
                struct vm_area_struct *vma;
@@ -1705,7 +1705,12 @@ static int svm_range_validate_and_map(struct mm_struct *mm,
                }
 
                svm_range_lock(prange);
-               if (!r && amdgpu_hmm_range_get_pages_done(hmm_range)) {
+
+               /* Free backing memory of hmm_range if it was initialized
+                * Overrride return value to TRY AGAIN only if prior returns
+                * were successful
+                */
+               if (hmm_range && amdgpu_hmm_range_get_pages_done(hmm_range) && !r) {
                        pr_debug("hmm update the range, need validate again\n");
                        r = -EAGAIN;
                }