From: Subject: [PATCH] drivers/crypto:caam:Map src buffer before access in CAAM driver Date: Wed, 11 Sep 2013 11:32:26 +0530 Message-ID: <1378879346-24500-1-git-send-email-Yashpal.Dutta@freescale.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Yashpal Dutta To: Return-path: Received: from co1ehsobe003.messaging.microsoft.com ([216.32.180.186]:39880 "EHLO co1outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752265Ab3IKGOn (ORCPT ); Wed, 11 Sep 2013 02:14:43 -0400 Received: from mail191-co1 (localhost [127.0.0.1]) by mail191-co1-R.bigfish.com (Postfix) with ESMTP id 1C4C9B400BB for ; Wed, 11 Sep 2013 06:14:43 +0000 (UTC) Received: from CO1EHSMHS024.bigfish.com (unknown [10.243.78.236]) by mail191-co1.bigfish.com (Postfix) with ESMTP id C175F180041 for ; Wed, 11 Sep 2013 06:14:41 +0000 (UTC) Sender: linux-crypto-owner@vger.kernel.org List-ID: From: Yashpal Dutta KMap the buffers before copying trailing bytes during hmac in CAAM driver into a session temporary buffer. This is required if pinned buffer from user-space is send to CAAM driver during hmac and is safe even if hmac request is generated from within kernel. Signed-off-by: Yashpal Dutta --- drivers/crypto/caam/sg_sw_sec4.h | 34 +++++++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 9 deletions(-) diff --git a/drivers/crypto/caam/sg_sw_sec4.h b/drivers/crypto/caam/sg_sw_sec4.h index e0037c8..9575985 100644 --- a/drivers/crypto/caam/sg_sw_sec4.h +++ b/drivers/crypto/caam/sg_sw_sec4.h @@ -117,6 +117,21 @@ static int dma_unmap_sg_chained(struct device *dev, struct scatterlist *sg, return nents; } +/* Map SG page in kernel virtual address space and copy */ +static inline void sg_map_copy(u8 *dest, struct scatterlist *sg, + int len, int offset) +{ + u8 *mapped_addr; + + /* + * Page here can be user-space pinned using get_user_pages + * Same must be kmapped before use and kunmapped subsequently + */ + mapped_addr = kmap_atomic(sg_page(sg)); + memcpy(dest, mapped_addr + offset, len); + kunmap_atomic(mapped_addr); +} + /* Copy from len bytes of sg to dest, starting from beginning */ static inline void sg_copy(u8 *dest, struct scatterlist *sg, unsigned int len) { @@ -124,15 +139,15 @@ static inline void sg_copy(u8 *dest, struct scatterlist *sg, unsigned int len) int cpy_index = 0, next_cpy_index = current_sg->length; while (next_cpy_index < len) { - memcpy(dest + cpy_index, (u8 *) sg_virt(current_sg), - current_sg->length); + sg_map_copy(dest + cpy_index, current_sg, current_sg->length, + current_sg->offset); current_sg = scatterwalk_sg_next(current_sg); cpy_index = next_cpy_index; next_cpy_index += current_sg->length; } if (cpy_index < len) - memcpy(dest + cpy_index, (u8 *) sg_virt(current_sg), - len - cpy_index); + sg_map_copy(dest + cpy_index, current_sg, len-cpy_index, + current_sg->offset); } /* Copy sg data, from to_skip to end, to dest */ @@ -140,7 +155,7 @@ static inline void sg_copy_part(u8 *dest, struct scatterlist *sg, int to_skip, unsigned int end) { struct scatterlist *current_sg = sg; - int sg_index, cpy_index; + int sg_index, cpy_index, offset; sg_index = current_sg->length; while (sg_index <= to_skip) { @@ -148,9 +163,10 @@ static inline void sg_copy_part(u8 *dest, struct scatterlist *sg, sg_index += current_sg->length; } cpy_index = sg_index - to_skip; - memcpy(dest, (u8 *) sg_virt(current_sg) + - current_sg->length - cpy_index, cpy_index); - current_sg = scatterwalk_sg_next(current_sg); - if (end - sg_index) + offset = current_sg->offset + current_sg->length - cpy_index; + sg_map_copy(dest, current_sg, cpy_index, offset); + if (end - sg_index) { + current_sg = scatterwalk_sg_next(current_sg); sg_copy(dest + cpy_index, current_sg, end - sg_index); + } } -- 1.7.10.4