4.4-stable review patch. If anyone has any objections, please let me know.
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From: Stephan Mueller smueller@chronox.de
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@googlegroups.com Signed-off-by: Stephan Mueller smueller@chronox.de Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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);