crypto: af_alg - update correct dst SGL entry

When two adjacent TX SGL are processed and parts of both TX SGLs are pulled into the per-request TX SGL, the wrong per-request TX SGL entries were updated. This fixes a NULL pointer dereference when a cipher implementation walks the TX SGL where some of the SGL entries were NULL. Fixes: e870456 ("crypto: algif_skcipher - overhaul memory...") Signed-off-by: Stephan Mueller <[email protected]> Signed-off-by: Herbert Xu <[email protected]>
josf · Sep 20, 2017 · e117765 · e117765
1 parent c056d91
commit e117765
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
@@ -619,14 +619,14 @@ void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
 	struct af_alg_ctx *ctx = ask->private;
 	struct af_alg_tsgl *sgl;
 	struct scatterlist *sg;
-	unsigned int i, j;
+	unsigned int i, j = 0;
 
 	while (!list_empty(&ctx->tsgl_list)) {
 		sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
 				       list);
 		sg = sgl->sg;
 
-		for (i = 0, j = 0; i < sgl->cur; i++) {
+		for (i = 0; i < sgl->cur; i++) {
 			size_t plen = min_t(size_t, used, sg[i].length);
 			struct page *page = sg_page(sg + i);