From 9b2f4cb65f7083cde86553cd56d6c2878e04932a Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 11 Sep 2012 12:05:45 +0800 Subject: [PATCH] crypto: authenc - Fix crash with zero-length assoc data The authenc code doesn't deal with zero-length associated data correctly and ends up constructing a zero-length sg entry which causes a crash when it's fed into the crypto system. This patch fixes this by avoiding the code-path that triggers the SG construction if we have no associated data. This isn't the most optimal fix as it means that we'll end up using the fallback code-path even when we could still execute the digest function. However, this isn't a big deal as nobody but the test path would supply zero-length associated data. Reported-by: Romain Francoise Signed-off-by: Herbert Xu Tested-by: Romain Francoise --- crypto/authenc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/crypto/authenc.c b/crypto/authenc.c index 5ef7ba6b6a76..d0583a4489e6 100644 --- a/crypto/authenc.c +++ b/crypto/authenc.c @@ -336,7 +336,7 @@ static int crypto_authenc_genicv(struct aead_request *req, u8 *iv, cryptlen += ivsize; } - if (sg_is_last(assoc)) { + if (req->assoclen && sg_is_last(assoc)) { authenc_ahash_fn = crypto_authenc_ahash; sg_init_table(asg, 2); sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset); @@ -490,7 +490,7 @@ static int crypto_authenc_iverify(struct aead_request *req, u8 *iv, cryptlen += ivsize; } - if (sg_is_last(assoc)) { + if (req->assoclen && sg_is_last(assoc)) { authenc_ahash_fn = crypto_authenc_ahash; sg_init_table(asg, 2); sg_set_page(asg, sg_page(assoc), assoc->length, assoc->offset);