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author | Herbert Xu <herbert@gondor.apana.org.au> | 2012-09-11 12:05:45 +0800 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2012-09-11 12:05:45 +0800 |
commit | 9b2f4cb65f7083cde86553cd56d6c2878e04932a (patch) | |
tree | eb9a4d9fa6a66bf95cd60ff76e2ebc46ccb59115 | |
parent | 3b75a2c126c4b573553856e0fe08d1bb020ca8c3 (diff) | |
download | lwn-9b2f4cb65f7083cde86553cd56d6c2878e04932a.tar.gz lwn-9b2f4cb65f7083cde86553cd56d6c2878e04932a.zip |
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 <romain@orebokech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Romain Francoise <romain@orebokech.com>
-rw-r--r-- | crypto/authenc.c | 4 |
1 files 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); |