lkml.org 
[lkml]   [2016]   [Jan]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3.16.y-ckt 103/126] crypto: talitos - Fix timing leak in ESP ICV verification
Date
3.16.7-ckt22 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Gstir <david@sigma-star.at>

commit 79960943fdc114fd4583c9ab164b5c89da7aa601 upstream.

Using non-constant time memcmp() makes the verification of the authentication
tag in the decrypt path vulnerable to timing attacks. Fix this by using
crypto_memneq() instead.

Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
drivers/crypto/talitos.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c
index 307931528eb2..da328ed633fb 100644
--- a/drivers/crypto/talitos.c
+++ b/drivers/crypto/talitos.c
@@ -870,8 +870,8 @@ static void ipsec_esp_decrypt_swauth_done(struct device *dev,
icvdata = &edesc->link_tbl[0];

sg = sg_last(req->dst, edesc->dst_nents ? : 1);
- err = memcmp(icvdata, (char *)sg_virt(sg) + sg->length -
- ctx->authsize, ctx->authsize) ? -EBADMSG : 0;
+ err = crypto_memneq(icvdata, (char *)sg_virt(sg) + sg->length -
+ ctx->authsize, ctx->authsize) ? -EBADMSG : 0;
}

kfree(edesc);

\
 
 \ /
  Last update: 2016-01-06 12:21    [W:0.272 / U:0.020 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site