5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ruoyu Wang [ Upstream commit 25056329384010a8672552b134f609601dc4f80e ] chainup_buffers() builds a linked list of buffer descriptors for a scatterlist. If dma_pool_alloc() fails while constructing the list, the current code sets buf to NULL and later dereferences it unconditionally at the end of the function: buf->next = NULL; buf->phys_next = 0; This can lead to a null-pointer dereference on allocation failure. If the failure happens after part of the descriptor chain has already been allocated and DMA-mapped, the partially constructed chain also needs to be released. Fix this by terminating the partially constructed chain on allocation failure and letting the callers unwind it via their existing cleanup paths. Also fix ablk_perform() to preserve the hook pointers before checking for failure, so partially built chains can be freed correctly. Signed-off-by: Ruoyu Wang Acked-by: Linus Walleij Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin --- drivers/crypto/ixp4xx_crypto.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/drivers/crypto/ixp4xx_crypto.c b/drivers/crypto/ixp4xx_crypto.c index 2bf315554f02a..4cd743244dbb0 100644 --- a/drivers/crypto/ixp4xx_crypto.c +++ b/drivers/crypto/ixp4xx_crypto.c @@ -883,8 +883,9 @@ static struct buffer_desc *chainup_buffers(struct device *dev, ptr = sg_virt(sg); next_buf = dma_pool_alloc(buffer_pool, flags, &next_buf_phys); if (!next_buf) { - buf = NULL; - break; + buf->next = NULL; + buf->phys_next = 0; + return NULL; } sg_dma_address(sg) = dma_map_single(dev, ptr, len, dir); buf->next = next_buf; @@ -982,7 +983,7 @@ static int ablk_perform(struct skcipher_request *req, int encrypt) unsigned int nbytes = req->cryptlen; enum dma_data_direction src_direction = DMA_BIDIRECTIONAL; struct ablk_ctx *req_ctx = skcipher_request_ctx(req); - struct buffer_desc src_hook; + struct buffer_desc *buf, src_hook; struct device *dev = &pdev->dev; unsigned int offset; gfp_t flags = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? @@ -1024,22 +1025,24 @@ static int ablk_perform(struct skcipher_request *req, int encrypt) /* This was never tested by Intel * for more than one dst buffer, I think. */ req_ctx->dst = NULL; - if (!chainup_buffers(dev, req->dst, nbytes, &dst_hook, - flags, DMA_FROM_DEVICE)) - goto free_buf_dest; - src_direction = DMA_TO_DEVICE; + buf = chainup_buffers(dev, req->dst, nbytes, &dst_hook, + flags, DMA_FROM_DEVICE); req_ctx->dst = dst_hook.next; crypt->dst_buf = dst_hook.phys_next; + if (!buf) + goto free_buf_dest; + src_direction = DMA_TO_DEVICE; } else { req_ctx->dst = NULL; } req_ctx->src = NULL; - if (!chainup_buffers(dev, req->src, nbytes, &src_hook, flags, - src_direction)) - goto free_buf_src; - + buf = chainup_buffers(dev, req->src, nbytes, &src_hook, flags, + src_direction); req_ctx->src = src_hook.next; crypt->src_buf = src_hook.phys_next; + if (!buf) + goto free_buf_src; + crypt->ctl_flags |= CTL_FLAG_PERFORM_ABLK; qmgr_put_entry(send_qid, crypt_virt2phys(crypt)); BUG_ON(qmgr_stat_overflow(send_qid)); -- 2.53.0