3.2.102-rc1 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>
[bwh: Backported to 3.2: The CRYPTO_ALG_KERN_DRIVER_ONLY flag is not supported,
so set allowed to 0]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -149,6 +149,7 @@ EXPORT_SYMBOL_GPL(af_alg_release_parent)
static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
+ const u32 allowed = 0;
struct sock *sk = sock->sk;
struct alg_sock *ask = alg_sk(sk);
struct sockaddr_alg *sa = (void *)uaddr;
@@ -156,6 +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;
