[PATCH 5.8 213/232] crypto: algif_aead - fix uninitialized ctx->init

From: Greg Kroah-Hartman
Date: Thu Aug 20 2020 - 09:28:12 EST


From: Ondrej Mosnacek <omosnace@xxxxxxxxxx>

[ Upstream commit 21dfbcd1f5cbff9cf2f9e7e43475aed8d072b0dd ]

In skcipher_accept_parent_nokey() the whole af_alg_ctx structure is
cleared by memset() after allocation, so add such memset() also to
aead_accept_parent_nokey() so that the new "init" field is also
initialized to zero. Without that the initial ctx->init checks might
randomly return true and cause errors.

While there, also remove the redundant zero assignments in both
functions.

Found via libkcapi testsuite.

Cc: Stephan Mueller <smueller@xxxxxxxxxx>
Fixes: f3c802a1f300 ("crypto: algif_aead - Only wake up when ctx->more is zero")
Suggested-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
crypto/algif_aead.c | 6 ------
crypto/algif_skcipher.c | 7 +------
2 files changed, 1 insertion(+), 12 deletions(-)

diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c
index d48d2156e6210..43c6aa784858b 100644
--- a/crypto/algif_aead.c
+++ b/crypto/algif_aead.c
@@ -558,12 +558,6 @@ static int aead_accept_parent_nokey(void *private, struct sock *sk)

INIT_LIST_HEAD(&ctx->tsgl_list);
ctx->len = len;
- ctx->used = 0;
- atomic_set(&ctx->rcvused, 0);
- ctx->more = 0;
- ctx->merge = 0;
- ctx->enc = 0;
- ctx->aead_assoclen = 0;
crypto_init_wait(&ctx->wait);

ask->private = ctx;
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index a51ba22fef58f..81c4022285a7c 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -333,6 +333,7 @@ static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
ctx = sock_kmalloc(sk, len, GFP_KERNEL);
if (!ctx)
return -ENOMEM;
+ memset(ctx, 0, len);

ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(tfm),
GFP_KERNEL);
@@ -340,16 +341,10 @@ static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
sock_kfree_s(sk, ctx, len);
return -ENOMEM;
}
-
memset(ctx->iv, 0, crypto_skcipher_ivsize(tfm));

INIT_LIST_HEAD(&ctx->tsgl_list);
ctx->len = len;
- ctx->used = 0;
- atomic_set(&ctx->rcvused, 0);
- ctx->more = 0;
- ctx->merge = 0;
- ctx->enc = 0;
crypto_init_wait(&ctx->wait);

ask->private = ctx;
--
2.25.1