| From | Luis Henriques <> | Subject | [PATCH 3.16.y-ckt 103/126] crypto: talitos - Fix timing leak in ESP ICV verification | Date | Wed, 6 Jan 2016 10:37:12 +0000 |
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3.16.7-ckt22 -stable review patch. If anyone has any objections, please let me know.
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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);
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