crypto: api - Fix race condition in crypto_spawn_alg

The function crypto_spawn_alg is racy because it drops the lock
before shooting the dying algorithm.  The algorithm could disappear
altogether before we shoot it.

This patch fixes it by moving the shooting into the locked section.

Fixes: 6bfd48096f ("[CRYPTO] api: Added spawns")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Herbert Xu
2019-12-07 22:15:15 +08:00
parent 4a2abbc6b8
commit 73669cc556
3 changed files with 6 additions and 14 deletions

View File

@@ -331,13 +331,12 @@ static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
return len;
}
void crypto_shoot_alg(struct crypto_alg *alg)
static void crypto_shoot_alg(struct crypto_alg *alg)
{
down_write(&crypto_alg_sem);
alg->cra_flags |= CRYPTO_ALG_DYING;
up_write(&crypto_alg_sem);
}
EXPORT_SYMBOL_GPL(crypto_shoot_alg);
struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
u32 mask)