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crypto: pkcs7 - Fix unaligned access in pkcs7_verify()

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On sparc, we see unaligned access messages on each modprobe[-r]:

Kernel unaligned access at TPC[6ad9b4] pkcs7_verify [..]
Kernel unaligned access at TPC[6a5484] crypto_shash_finup [..]
Kernel unaligned access at TPC[6a5390] crypto_shash_update [..]
Kernel unaligned access at TPC[10150308] sha1_sparc64_update [..]
Kernel unaligned access at TPC[101501ac] __sha1_sparc64_update [..]

These ware triggered by mod_verify_sig() invocations of pkcs_verify(), and
are are being caused by an unaligned desc at (sha1, digest_size is 0x14)
        desc = digest + digest_size;

To fix this, pkcs7_verify needs to make sure that desc is pointing
at an aligned value past the digest_size, and kzalloc appropriately,
taking alignment values into consideration.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Sowmini Varadhan 2015-10-13 10:54:01 -04:00 committed by Herbert Xu
parent 5a4eea2658
commit 62f57d05e2
1 changed files with 3 additions and 2 deletions
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5
crypto/asymmetric_keys/pkcs7_verify.c
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@ -49,11 +49,12 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
sinfo->sig.digest_size = digest_size = crypto_shash_digestsize(tfm);
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_no_desc;
desc = digest + digest_size;
desc = PTR_ALIGN(digest + digest_size, __alignof__(*desc));
desc->tfm = tfm;
desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;