3.16.57-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 3.16: We don't have a CRYPTO_ALG_INTENRAL flag and didn't blacklist it here] 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 = CRYPTO_ALG_KERN_DRIVER_ONLY; 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;