[PATCH v3] crypto: AF_ALG - whitelist mask and type
From: Stephan Müller <hidden>
Date: 2018-01-02 07:53:45
Also in:
lkml
Subsystem:
crypto api, the rest · Maintainers:
Herbert Xu, "David S. Miller", Linus Torvalds
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. Signed-off-by: Stephan Mueller <redacted> --- crypto/af_alg.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 35d4dcea381f..5231f421ad00 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c@@ -150,7 +150,7 @@ 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;
@@ -158,6 +158,10 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 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;
@@ -176,9 +180,7 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 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);
--
2.14.3