From 93070d339d7bc6f6b07b64faf5134fd144e8ec48 Mon Sep 17 00:00:00 2001 From: David Windsor Date: Thu, 24 Aug 2017 16:58:35 -0700 Subject: [PATCH] caif: Define usercopy region in caif proto slab cache The CAIF channel connection request parameters need to be copied to/from userspace. In support of usercopy hardening, this patch defines a region in the struct proto slab cache in which userspace copy operations are allowed. example usage trace: net/caif/caif_socket.c: setsockopt(...): ... copy_from_user(&cf_sk->conn_req.param.data, ..., ol) This region is known as the slab cache's usercopy region. Slab caches can now check that each dynamically sized copy operation involving cache-managed memory falls entirely within the slab's usercopy region. This patch is modified from Brad Spengler/PaX Team's PAX_USERCOPY whitelisting code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Signed-off-by: David Windsor [kees: split from network patch, provide usage trace] Cc: "David S. Miller" Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook --- net/caif/caif_socket.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c index 632d5a4..c76d513 100644 --- a/net/caif/caif_socket.c +++ b/net/caif/caif_socket.c @@ -1032,6 +1032,8 @@ static int caif_create(struct net *net, struct socket *sock, int protocol, static struct proto prot = {.name = "PF_CAIF", .owner = THIS_MODULE, .obj_size = sizeof(struct caifsock), + .useroffset = offsetof(struct caifsock, conn_req.param), + .usersize = sizeof_field(struct caifsock, conn_req.param) }; if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN)) -- 2.7.4