[PATCH 1/2] crypto/x509: Fix unaligned access in x509_get_sig_params()

From: Sowmini Varadhan
Date: Mon Oct 19 2015 - 17:24:47 EST


x509_get_sig_params() has the same code pattern as the one in
pkcs7_verify() that is fixed by commit 62f57d05e287 ("crypto: pkcs7 - Fix
unaligned access in pkcs7_verify()") so apply a similar fix here: make
sure that desc is pointing at an algined value past the digest_size,
and take alignment values into consideration when doing kzalloc()

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@xxxxxxxxxx>
---
crypto/asymmetric_keys/x509_public_key.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 1970966..68c3c40 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -194,14 +194,15 @@ int x509_get_sig_params(struct x509_certificate *cert)
* digest storage space.
*/
ret = -ENOMEM;
- digest = kzalloc(digest_size + desc_size, GFP_KERNEL);
+ digest = kzalloc(ALIGN(digest_size, __alignof__(*desc)) + desc_size,
+ GFP_KERNEL);
if (!digest)
goto error;

cert->sig.digest = digest;
cert->sig.digest_size = digest_size;

- desc = digest + digest_size;
+ desc = PTR_ALIGN(digest + digest_size, __alignof__(*desc));
desc->tfm = tfm;
desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;

--
1.7.1

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