Re: [PATCH] crypto: testmgr.c: test misuse of result in ahash

[Herbert Xu]

On Tue, Jan 16, 2018 at 03:26:13PM +0100, Kamil Konieczny wrote:
> Async hash operations can use result pointer in final/finup/digest,
> but not in init/update/export/import, so test it for misuse.
> 
> Signed-off-by: Kamil Konieczny 

Patch applied.  Thanks.
-- 
Email: Herbert Xu 
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

[PATCH] crypto: testmgr.c: test misuse of result in ahash

[Kamil Konieczny]

Async hash operations can use result pointer in final/finup/digest,
but not in init/update/export/import, so test it for misuse.

Signed-off-by: Kamil Konieczny 
---
Tested with crypto run-time self test on Odroid-U3 with Exynos 4412 CPU
with insmod s5p-sss.ko

 crypto/testmgr.c | 39 +++
 1 file changed, 39 insertions(+)

diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 44a85d4b3561..d5e23a142a04 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -177,6 +177,18 @@ static void testmgr_free_buf(char *buf[XBUFSIZE])
free_page((unsigned long)buf[i]);
 }
 
+static int ahash_guard_result(char *result, char c, int size)
+{
+   int i;
+
+   for (i = 0; i < size; i++) {
+   if (result[i] != c)
+   return -EINVAL;
+   }
+
+   return 0;
+}
+
 static int ahash_partial_update(struct ahash_request **preq,
struct crypto_ahash *tfm, const struct hash_testvec *template,
void *hash_buff, int k, int temp, struct scatterlist *sg,
@@ -186,6 +198,7 @@ static int ahash_partial_update(struct ahash_request **preq,
struct ahash_request *req;
int statesize, ret = -EINVAL;
static const unsigned char guard[] = { 0x00, 0xba, 0xad, 0x00 };
+   int digestsize = crypto_ahash_digestsize(tfm);
 
req = *preq;
statesize = crypto_ahash_statesize(
@@ -196,12 +209,19 @@ static int ahash_partial_update(struct ahash_request 
**preq,
goto out_nostate;
}
memcpy(state + statesize, guard, sizeof(guard));
+   memset(result, 1, digestsize);
ret = crypto_ahash_export(req, state);
WARN_ON(memcmp(state + statesize, guard, sizeof(guard)));
if (ret) {
pr_err("alg: hash: Failed to export() for %s\n", algo);
goto out;
}
+   ret = ahash_guard_result(result, 1, digestsize);
+   if (ret) {
+   pr_err("alg: hash: Failed, export used req->result for %s\n",
+  algo);
+   goto out;
+   }
ahash_request_free(req);
req = ahash_request_alloc(tfm, GFP_KERNEL);
if (!req) {
@@ -221,6 +241,12 @@ static int ahash_partial_update(struct ahash_request 
**preq,
pr_err("alg: hash: Failed to import() for %s\n", algo);
goto out;
}
+   ret = ahash_guard_result(result, 1, digestsize);
+   if (ret) {
+   pr_err("alg: hash: Failed, import used req->result for %s\n",
+  algo);
+   goto out;
+   }
ret = crypto_wait_req(crypto_ahash_update(req), wait);
if (ret)
goto out;
@@ -316,18 +342,31 @@ static int __test_hash(struct crypto_ahash *tfm,
goto out;
}
} else {
+   memset(result, 1, digest_size);
ret = crypto_wait_req(crypto_ahash_init(req), );
if (ret) {
pr_err("alg: hash: init failed on test %d "
   "for %s: ret=%d\n", j, algo, -ret);
goto out;
}
+   ret = ahash_guard_result(result, 1, digest_size);
+   if (ret) {
+   pr_err("alg: hash: init failed on test %d "
+  "for %s: used req->result\n", j, algo);
+   goto out;
+   }
ret = crypto_wait_req(crypto_ahash_update(req), );
if (ret) {
pr_err("alg: hash: update failed on test %d "
   "for %s: ret=%d\n", j, algo, -ret);
goto out;
}
+   ret = ahash_guard_result(result, 1, digest_size);
+   if (ret) {
+   pr_err("alg: hash: update failed on test %d "
+  "for %s: used req->result\n", j, algo);
+   goto out;
+   }
ret = crypto_wait_req(crypto_ahash_final(req), );
if (ret) {
pr_err("alg: hash: final failed on test %d "
-- 
2.15.0