From: Yehuda Sadeh Subject: [PATCH] shash: fix unaligned calculation with short length Date: Thu, 26 Mar 2009 14:12:21 -0700 Message-ID: <1238101941-12859-1-git-send-email-yehuda@hq.newdream.net> Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Yehuda Sadeh To: herbert@gondor.apana.org.au Return-path: Received: from mail.hq.newdream.net ([66.33.206.127]:58985 "EHLO mail.hq.newdream.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754109AbZCZV3f (ORCPT ); Thu, 26 Mar 2009 17:29:35 -0400 Sender: linux-crypto-owner@vger.kernel.org List-ID: When the total length is shorter than the calculated number of unaligned bytes, the call to shash->update breaks. For example, calling crc32c on unaligned buffer with length of 1 can result in a system crash. Signed-off-by: Yehuda Sadeh --- crypto/shash.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/crypto/shash.c b/crypto/shash.c index d5a2b61..6792a67 100644 --- a/crypto/shash.c +++ b/crypto/shash.c @@ -82,6 +82,9 @@ static int shash_update_unaligned(struct shash_desc *desc, const u8 *data, u8 buf[shash_align_buffer_size(unaligned_len, alignmask)] __attribute__ ((aligned)); + if (unaligned_len > len) + unaligned_len = len; + memcpy(buf, data, unaligned_len); return shash->update(desc, buf, unaligned_len) ?: -- 1.5.6.5