]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blobdiff - crypto/algapi.c
crypto: api - Fix race condition in crypto_spawn_alg
[mirror_ubuntu-bionic-kernel.git] / crypto / algapi.c
index f4d8deff5fcdd63f02fa04ee0286dea9314b2f4f..0d62e563592a5f23072c8b8a81a279dffb0d21a2 100644 (file)
@@ -662,22 +662,16 @@ EXPORT_SYMBOL_GPL(crypto_drop_spawn);
 static struct crypto_alg *crypto_spawn_alg(struct crypto_spawn *spawn)
 {
        struct crypto_alg *alg;
-       struct crypto_alg *alg2;
 
        down_read(&crypto_alg_sem);
        alg = spawn->alg;
-       alg2 = alg;
-       if (alg2)
-               alg2 = crypto_mod_get(alg2);
-       up_read(&crypto_alg_sem);
-
-       if (!alg2) {
-               if (alg)
-                       crypto_shoot_alg(alg);
-               return ERR_PTR(-EAGAIN);
+       if (alg && !crypto_mod_get(alg)) {
+               alg->cra_flags |= CRYPTO_ALG_DYING;
+               alg = NULL;
        }
+       up_read(&crypto_alg_sem);
 
-       return alg;
+       return alg ?: ERR_PTR(-EAGAIN);
 }
 
 struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,