crypto: api - fix unexpectedly getting generic implementation (2bbb3375) · Commits · 戴 / test

When CONFIG_CRYPTO_MANAGER_EXTRA_TESTS=y, the first lookup of an algorithm that needs to be instantiated using a template will always get the generic implementation, even when an accelerated one is available. This happens because the extra self-tests for the accelerated implementation allocate the generic implementation for comparison purposes, and then crypto_alg_tested() for the generic implementation "fulfills" the original request (i.e. sets crypto_larval::adult). This patch fixes this by only fulfilling the original request if we are currently the best outstanding larval as judged by the priority. If we're not the best then we will ask all waiters on that larval request to retry the lookup. Note that this patch introduces a behaviour change when the module providing the new algorithm is unregistered during the process. Previously we would have failed with ENOENT, after the patch we will instead redo the lookup. Fixes: ("crypto: testmgr - fuzz hashes against...") Fixes: ("crypto: testmgr - fuzz skciphers against...") Fixes: ("crypto: testmgr - fuzz AEADs against...") Reported-by:

Eric Biggers <ebiggers@google.com> Signed-off-by:

Herbert Xu <herbert@gondor.apana.org.au> Reviewed-by:

Eric Biggers <ebiggers@google.com> Signed-off-by:

Herbert Xu <herbert@gondor.apana.org.au>

crypto/algapi.c

+21 −3

Original line number	Diff line number	Diff line
		@@ -284,6 +284,7 @@ void crypto_alg_tested(const char *name, int err)
		struct crypto_alg *alg;
		struct crypto_alg *q;
		LIST_HEAD(list);
		bool best;

		down_write(&crypto_alg_sem);
		list_for_each_entry(q, &crypto_alg_list, cra_list) {
		@@ -307,6 +308,21 @@ found:

		alg->cra_flags \|= CRYPTO_ALG_TESTED;

		/* Only satisfy larval waiters if we are the best. */
		best = true;
		list_for_each_entry(q, &crypto_alg_list, cra_list) {
		if (crypto_is_moribund(q) \|\| !crypto_is_larval(q))
		continue;

		if (strcmp(alg->cra_name, q->cra_name))
		continue;

		if (q->cra_priority > alg->cra_priority) {
		best = false;
		break;
		}
		}

		list_for_each_entry(q, &crypto_alg_list, cra_list) {
		if (q == alg)
		continue;
		@@ -330,10 +346,12 @@ found:
		continue;
		if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
		continue;
		if (!crypto_mod_get(alg))
		continue;

		if (best && crypto_mod_get(alg))
		larval->adult = alg;
		else
		larval->adult = ERR_PTR(-EAGAIN);

		continue;
		}

crypto/api.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -97,7 +97,7 @@ static void crypto_larval_destroy(struct crypto_alg *alg)
		struct crypto_larval larval = (void )alg;

		BUG_ON(!crypto_is_larval(alg));
		if (larval->adult)
		if (!IS_ERR_OR_NULL(larval->adult))
		crypto_mod_put(larval->adult);
		kfree(larval);
		}
		@@ -178,6 +178,8 @@ static struct crypto_alg crypto_larval_wait(struct crypto_alg alg)
		alg = ERR_PTR(-ETIMEDOUT);
		else if (!alg)
		alg = ERR_PTR(-ENOENT);
		else if (IS_ERR(alg))
		;
		else if (crypto_is_test_larval(larval) &&
		!(alg->cra_flags & CRYPTO_ALG_TESTED))
		alg = ERR_PTR(-EAGAIN);

Admin message