From 2d45a7e89833f88b38112292ff227af437f81f2f Mon Sep 17 00:00:00 2001 From: Stephan Mueller Date: Thu, 10 Aug 2017 16:40:03 +0200 Subject: [PATCH] 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 Signed-off-by: Herbert Xu --- crypto/af_alg.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/crypto/af_alg.c b/crypto/af_alg.c index d6936c0e08d9..ffa9f4ccd9b4 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); } -- 2.20.1