crypto: af_alg - get_page upon reassignment to TX SGL
When a page is assigned to a TX SGL, call get_page to increment the
reference counter. It is possible that one page is referenced in
multiple SGLs:
- in the global TX SGL in case a previous af_alg_pull_tsgl only
reassigned parts of a page to a per-request TX SGL
- in the per-request TX SGL as assigned by af_alg_pull_tsgl
Note, multiple requests can be active at the same time whose TX SGLs all
point to different parts of the same page.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index d6936c0..ffa9f4c 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -641,9 +641,9 @@ void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
if (dst_offset >= plen) {
/* discard page before offset */
dst_offset -= plen;
- put_page(page);
} else {
/* reassign page to dst after offset */
+ get_page(page);
sg_set_page(dst + j, page,
plen - dst_offset,
sg[i].offset + dst_offset);
@@ -661,9 +661,7 @@ void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
if (sg[i].length)
return;
- if (!dst)
- put_page(page);
-
+ put_page(page);
sg_assign_page(sg + i, NULL);
}
