Am 13.07.23 um 21:47 schrieb Ville Syrjala:
From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
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@xxxxxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: linux-media@xxxxxxxxxxxxxxx
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: linaro-mm-sig@xxxxxxxxxxxxxxxx
Fixes: d3c80698c9f5 ("dma-buf: use new iterator in dma_resv_get_fences v3")
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Good catch, Reviewed-by: Christian König <christian.koenig@xxxxxxx>
Should I add a CC: stable and push to drm-misc-fixes?
Thanks,
Christian.
---
drivers/dma-buf/dma-resv.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index b6f71eb00866..38b4110378de 100644
--- 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 *obj, enum dma_resv_usage usage,
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 *obj, enum dma_resv_usage usage,
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);
