This patch changes the p8_ghash driver to use ghash-generic as a fixed
fallback implementation. This allows the correct value of descsize to be
defined directly in its shash_alg structure and avoids problems with
incorrect buffer sizes when its state is exported or imported.
Reported-by: Jan Stancek <jstancek@xxxxxxxxxx>
Signed-off-by: Marcelo Cerri <marcelo.cerri@xxxxxxxxxxxxx>
---
drivers/crypto/vmx/ghash.c | 31 ++++++++++++++++---------------
1 file changed, 16 insertions(+), 15 deletions(-)
diff --git a/drivers/crypto/vmx/ghash.c b/drivers/crypto/vmx/ghash.c
index 6c999cb0..27a94a1 100644
--- a/drivers/crypto/vmx/ghash.c
+++ b/drivers/crypto/vmx/ghash.c
@@ -26,16 +26,13 @@
#include <linux/hardirq.h>
#include <asm/switch_to.h>
#include <crypto/aes.h>
+#include <crypto/ghash.h>
#include <crypto/scatterwalk.h>
#include <crypto/internal/hash.h>
#include <crypto/b128ops.h>
#define IN_INTERRUPT in_interrupt()
-#define GHASH_BLOCK_SIZE (16)
-#define GHASH_DIGEST_SIZE (16)
-#define GHASH_KEY_LEN (16)
-
void gcm_init_p8(u128 htable[16], const u64 Xi[2]);
void gcm_gmult_p8(u64 Xi[2], const u128 htable[16]);
void gcm_ghash_p8(u64 Xi[2], const u128 htable[16],
@@ -55,16 +52,11 @@ struct p8_ghash_desc_ctx {
static int p8_ghash_init_tfm(struct crypto_tfm *tfm)
{
- const char *alg;
+ const char *alg = "ghash-generic";
struct crypto_shash *fallback;
struct crypto_shash *shash_tfm = __crypto_shash_cast(tfm);
struct p8_ghash_ctx *ctx = crypto_tfm_ctx(tfm);
- if (!(alg = crypto_tfm_alg_name(tfm))) {
- printk(KERN_ERR "Failed to get algorithm name.\n");
- return -ENOENT;
- }
-
fallback = crypto_alloc_shash(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(fallback)) {
printk(KERN_ERR
@@ -78,10 +70,18 @@ static int p8_ghash_init_tfm(struct crypto_tfm *tfm)
crypto_shash_set_flags(fallback,
crypto_shash_get_flags((struct crypto_shash
*) tfm));
- ctx->fallback = fallback;
- shash_tfm->descsize = sizeof(struct p8_ghash_desc_ctx)
- + crypto_shash_descsize(fallback);
+ /* Check if the descsize defined in the algorithm is still enough. */
+ if (shash_tfm->descsize < sizeof(struct p8_ghash_desc_ctx)
+ + crypto_shash_descsize(fallback)) {
+ printk(KERN_ERR
+ "Desc size of the fallback implementation (%s) does not match the expected value: %lu vs %u\n",
+ alg,
+ shash_tfm->descsize - sizeof(struct p8_ghash_desc_ctx),
+ crypto_shash_descsize(fallback));
+ return -EINVAL;
+ }
+ ctx->fallback = fallback;
return 0;
}
@@ -113,7 +113,7 @@ static int p8_ghash_setkey(struct crypto_shash *tfm, const u8 *key,
{
struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(tfm));
- if (keylen != GHASH_KEY_LEN)
+ if (keylen != GHASH_BLOCK_SIZE)
return -EINVAL;
preempt_disable();
@@ -211,7 +211,8 @@ struct shash_alg p8_ghash_alg = {
.update = p8_ghash_update,
.final = p8_ghash_final,
.setkey = p8_ghash_setkey,
- .descsize = sizeof(struct p8_ghash_desc_ctx),
+ .descsize = sizeof(struct p8_ghash_desc_ctx)
+ + sizeof(struct ghash_desc_ctx),
.base = {
.cra_name = "ghash",
.cra_driver_name = "p8_ghash",
--
2.7.4
--
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