[PATCH v3 11/12] security, crypto: LLVMLinux: Remove VLAIS from ima_crypto.c

From: behanw
Date: Mon Sep 15 2014 - 03:32:51 EST


From: Behan Webster <behanw@xxxxxxxxxxxxxxxxxx>

Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99
compliant equivalent. This patch allocates the appropriate amount of memory
using a char array using the SHASH_DESC_ON_STACK macro.

The new code can be compiled with both gcc and clang.

Signed-off-by: Behan Webster <behanw@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Mark Charlebois <charlebm@xxxxxxxxx>
Reviewed-by: Jan-Simon MÃller <dl9pf@xxxxxx>
Cc: tglx@xxxxxxxxxxxxx
---
security/integrity/ima/ima_crypto.c | 51 +++++++++++++++++--------------------
1 file changed, 23 insertions(+), 28 deletions(-)

diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 0bd7328..bb55737 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -380,17 +380,14 @@ static int ima_calc_file_hash_tfm(struct file *file,
loff_t i_size, offset = 0;
char *rbuf;
int rc, read = 0;
- struct {
- struct shash_desc shash;
- char ctx[crypto_shash_descsize(tfm)];
- } desc;
+ SHASH_DESC_ON_STACK(shash, tfm);

- desc.shash.tfm = tfm;
- desc.shash.flags = 0;
+ shash->tfm = tfm;
+ shash->flags = 0;

hash->length = crypto_shash_digestsize(tfm);

- rc = crypto_shash_init(&desc.shash);
+ rc = crypto_shash_init(shash);
if (rc != 0)
return rc;

@@ -420,7 +417,7 @@ static int ima_calc_file_hash_tfm(struct file *file,
break;
offset += rbuf_len;

- rc = crypto_shash_update(&desc.shash, rbuf, rbuf_len);
+ rc = crypto_shash_update(shash, rbuf, rbuf_len);
if (rc)
break;
}
@@ -429,7 +426,7 @@ static int ima_calc_file_hash_tfm(struct file *file,
kfree(rbuf);
out:
if (!rc)
- rc = crypto_shash_final(&desc.shash, hash->digest);
+ rc = crypto_shash_final(shash, hash->digest);
return rc;
}

@@ -487,18 +484,17 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
struct ima_digest_data *hash,
struct crypto_shash *tfm)
{
- struct {
- struct shash_desc shash;
- char ctx[crypto_shash_descsize(tfm)];
- } desc;
+ char desc[sizeof(struct shash_desc) +
+ crypto_shash_descsize(tfm)] CRYPTO_MINALIGN_ATTR;
+ struct shash_desc *shash = (struct shash_desc *)desc;
int rc, i;

- desc.shash.tfm = tfm;
- desc.shash.flags = 0;
+ shash->tfm = tfm;
+ shash->flags = 0;

hash->length = crypto_shash_digestsize(tfm);

- rc = crypto_shash_init(&desc.shash);
+ rc = crypto_shash_init(shash);
if (rc != 0)
return rc;

@@ -508,7 +504,7 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
u32 datalen = field_data[i].len;

if (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) {
- rc = crypto_shash_update(&desc.shash,
+ rc = crypto_shash_update(shash,
(const u8 *) &field_data[i].len,
sizeof(field_data[i].len));
if (rc)
@@ -518,13 +514,13 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
data_to_hash = buffer;
datalen = IMA_EVENT_NAME_LEN_MAX + 1;
}
- rc = crypto_shash_update(&desc.shash, data_to_hash, datalen);
+ rc = crypto_shash_update(shash, data_to_hash, datalen);
if (rc)
break;
}

if (!rc)
- rc = crypto_shash_final(&desc.shash, hash->digest);
+ rc = crypto_shash_final(shash, hash->digest);

return rc;
}
@@ -565,15 +561,14 @@ static int __init ima_calc_boot_aggregate_tfm(char *digest,
{
u8 pcr_i[TPM_DIGEST_SIZE];
int rc, i;
- struct {
- struct shash_desc shash;
- char ctx[crypto_shash_descsize(tfm)];
- } desc;
+ char desc[sizeof(struct shash_desc) +
+ crypto_shash_descsize(tfm)] CRYPTO_MINALIGN_ATTR;
+ struct shash_desc *shash = (struct shash_desc *)desc;

- desc.shash.tfm = tfm;
- desc.shash.flags = 0;
+ shash->tfm = tfm;
+ shash->flags = 0;

- rc = crypto_shash_init(&desc.shash);
+ rc = crypto_shash_init(shash);
if (rc != 0)
return rc;

@@ -581,10 +576,10 @@ static int __init ima_calc_boot_aggregate_tfm(char *digest,
for (i = TPM_PCR0; i < TPM_PCR8; i++) {
ima_pcrread(i, pcr_i);
/* now accumulate with current aggregate */
- rc = crypto_shash_update(&desc.shash, pcr_i, TPM_DIGEST_SIZE);
+ rc = crypto_shash_update(shash, pcr_i, TPM_DIGEST_SIZE);
}
if (!rc)
- crypto_shash_final(&desc.shash, digest);
+ crypto_shash_final(shash, digest);
return rc;
}

--
1.9.1

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