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From: Roel Kluin <roel.kluin@gmail.com>
To: Herbert Xu <herbert@gondor.apana.org.au>,
	Mikael Pettersson <mikpe@it.uu.se>,
	"David S. Miller" <davem@davemloft.net>,
	linux-crypto@vger.kernel.org, Andrew Morton <akpm@linux-foundat
Subject: [PATCH] sha: prevent removal of memset as dead store in sha1_update()
Date: Thu, 25 Feb 2010 16:10:27 +0100	[thread overview]
Message-ID: <4B8692E3.9030509@gmail.com> (raw)

Due to optimization A call to memset() may be removed as a dead store when
the buffer is not used after its value is overwritten.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
see http://cwe.mitre.org/data/slices/2000.html#14

checkpatch.pl, compile and sparse tested. Comments?

diff --git a/crypto/sha1_generic.c b/crypto/sha1_generic.c
index 0416091..86de0da 100644
--- a/crypto/sha1_generic.c
+++ b/crypto/sha1_generic.c
@@ -49,8 +49,8 @@ static int sha1_update(struct shash_desc *desc, const u8 *data,
 	src = data;
 
 	if ((partial + len) > 63) {
-		u32 temp[SHA_WORKSPACE_WORDS];

             reply	other threads:[~2010-02-25 15:10 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-25 15:10 Roel Kluin [this message]
2010-02-25 15:17 ` [PATCH] sha: prevent removal of memset as dead store in sha1_update() David Miller
2010-02-25 15:31   ` roel kluin
2010-02-25 15:37     ` David Miller
2010-02-26 11:55     ` Andi Kleen
2010-02-26 14:20       ` Mikael Pettersson
2010-02-26 15:46         ` Mikael Pettersson
2010-02-26 15:55           ` Andi Kleen
2010-02-25 15:56 ` Mikael Pettersson
2010-02-25 16:16   ` Pekka Enberg
2010-02-25 16:29     ` Mikael Pettersson
2010-02-25 16:33     ` roel kluin
2010-02-25 17:06       ` roel kluin
2010-02-25 16:33   ` Brian Gerst
2010-02-25 17:09     ` Mikael Pettersson
2010-02-25 17:32       ` Brian Gerst
2010-02-25 19:47         ` Roel Kluin
2010-02-25 20:43           ` Roel Kluin

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