If accept(2) is called on socket type algif_hash with
MSG_MORE flag set and crypto_ahash_import fails,
sk2 is freed. However, it is also freed in af_alg_release,
leading to slab-use-after-free error.

Fixes: fe869cdb89c9 ("crypto: algif_hash - User-space interface for hash operations")
Signed-off-by: Ivan Pravdin <ipravdin.official@gmail.com>
---
 crypto/algif_hash.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c
index 5498a87249d3..e3f1a4852737 100644
--- a/crypto/algif_hash.c
+++ b/crypto/algif_hash.c
@@ -265,10 +265,6 @@ static int hash_accept(struct socket *sock, struct socket *newsock,
 		goto out_free_state;
 
 	err = crypto_ahash_import(&ctx2->req, state);
-	if (err) {
-		sock_orphan(sk2);
-		sock_put(sk2);
-	}
 
 out_free_state:
 	kfree_sensitive(state);
-- 
2.45.2

On Sun, May 18, 2025 at 06:41:02PM -0400, Ivan Pravdin wrote:
> If accept(2) is called on socket type algif_hash with
> MSG_MORE flag set and crypto_ahash_import fails,
> sk2 is freed. However, it is also freed in af_alg_release,
> leading to slab-use-after-free error.
> 
> Fixes: fe869cdb89c9 ("crypto: algif_hash - User-space interface for hash operations")
> Signed-off-by: Ivan Pravdin <ipravdin.official@gmail.com>
> ---
>  crypto/algif_hash.c | 4 ----
>  1 file changed, 4 deletions(-)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt