Commit 62f57d05 authored by Sowmini Varadhan's avatar Sowmini Varadhan Committed by Herbert Xu

crypto: pkcs7 - Fix unaligned access in pkcs7_verify()

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: default avatarSowmini Varadhan <>
Signed-off-by: default avatarHerbert Xu <>
parent 5a4eea26
......@@ -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,
if (!digest)
goto error_no_desc;
desc = digest + digest_size;
desc = PTR_ALIGN(digest + digest_size, __alignof__(*desc));
desc->tfm = tfm;
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