We need to check whether spawn->alg is NULL under lock as otherwise
the algorithm could be removed from under us after we have checked
it and found it to be non-NULL. This could cause us to remove the
spawn from a non-existent list.
Fixes: 6bfd48096ff8 ("[CRYPTO] api: Added spawns")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
diff --git a/crypto/algapi.c b/crypto/algapi.c
index 783006f4d339..6869feb31c99 100644
--- a/crypto/algapi.c
+++ b/crypto/algapi.c
@@ -668,11 +668,9 @@ EXPORT_SYMBOL_GPL(crypto_grab_spawn);
void crypto_drop_spawn(struct crypto_spawn *spawn)
{
- if (!spawn->alg)
- return;
-
down_write(&crypto_alg_sem);
- list_del(&spawn->list);
+ if (spawn->alg)
+ list_del(&spawn->list);
up_write(&crypto_alg_sem);
}
EXPORT_SYMBOL_GPL(crypto_drop_spawn);
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
