crypto: fix broken crypto_register_instance() module handling

Commit 9c521a2 ("crypto: api - remove instance when test failed") tried to grab a module reference count before the module was even set. Worse, it then goes on to free the module reference count after it is set so you quickly end up with a negative module reference count which prevents people from using any instances belonging to that module. This patch moves the module initialisation before the reference count. Reported-by: Linus Torvalds <[email protected]> Signed-off-by: Herbert Xu <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
lucamilanesio · Apr 16, 2015 · 34c9a0f · 34c9a0f
1 parent eea3a00
commit 34c9a0f
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/crypto/algapi.c b/crypto/algapi.c
@@ -525,12 +525,12 @@ int crypto_register_instance(struct crypto_template *tmpl,
 	if (err)
 		return err;
 
-	if (unlikely(!crypto_mod_get(&inst->alg)))
-		return -EAGAIN;
-
 	inst->alg.cra_module = tmpl->module;
 	inst->alg.cra_flags |= CRYPTO_ALG_INSTANCE;
 
+	if (unlikely(!crypto_mod_get(&inst->alg)))
+		return -EAGAIN;
+
 	down_write(&crypto_alg_sem);
 
 	larval = __crypto_register_alg(&inst->alg);