4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Stephan Mueller <smueller@xxxxxxxxxx>
commit bb30b8848c85e18ca7e371d0a869e94b3e383bdf upstream.
The user space interface allows specifying the type and mask field used
to allocate the cipher. Only a subset of the possible flags are intended
for user space. Therefore, white-list the allowed flags.
In case the user space caller uses at least one non-allowed flag, EINVAL
is returned.
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: Stephan Mueller <smueller@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
crypto/af_alg.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -149,7 +149,7 @@ EXPORT_SYMBOL_GPL(af_alg_release_parent)
static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
- const u32 forbidden = CRYPTO_ALG_INTERNAL;
+ const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
struct sock *sk = sock->sk;
struct alg_sock *ask = alg_sk(sk);
struct sockaddr_alg *sa = (void *)uaddr;
@@ -157,6 +157,10 @@ static int alg_bind(struct socket *sock,
void *private;
int err;
+ /* If caller uses non-allowed flag, return error. */
+ if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
+ return -EINVAL;
+
if (sock->state == SS_CONNECTED)
return -EINVAL;
@@ -175,9 +179,7 @@ static int alg_bind(struct socket *sock,
if (IS_ERR(type))
return PTR_ERR(type);
- private = type->bind(sa->salg_name,
- sa->salg_feat & ~forbidden,
- sa->salg_mask & ~forbidden);
+ private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
if (IS_ERR(private)) {
module_put(type->owner);
return PTR_ERR(private);