packet: compat support for sock_fprog

[mirror_ubuntu-zesty-kernel.git] / net / compat.c

diff --git a/net/compat.c b/net/compat.c
index 1373947efb502753998437f8cc2ac3c71f0aae68..1cd2ec046164a659d7e4ad1b1acc24eceb780a6e 100644 (file)
--- a/net/compat.c
+++ b/net/compat.c
@@ -309,8 +309,8 @@ void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm)
        __scm_destroy(scm);
 }
 
-static int do_set_attach_filter(struct socket *sock, int level, int optname,
-                               char __user *optval, unsigned int optlen)
+/* allocate a 64-bit sock_fprog on the user stack for duration of syscall. */
+struct sock_fprog __user *get_compat_bpf_fprog(char __user *optval)
 {
        struct compat_sock_fprog __user *fprog32 = (struct compat_sock_fprog __user *)optval;
        struct sock_fprog __user *kfprog = compat_alloc_user_space(sizeof(struct sock_fprog));
@@ -323,6 +323,19 @@ static int do_set_attach_filter(struct socket *sock, int level, int optname,
            __get_user(ptr, &fprog32->filter) ||
            __put_user(len, &kfprog->len) ||
            __put_user(compat_ptr(ptr), &kfprog->filter))
+               return NULL;
+
+       return kfprog;
+}
+EXPORT_SYMBOL_GPL(get_compat_bpf_fprog);
+
+static int do_set_attach_filter(struct socket *sock, int level, int optname,
+                               char __user *optval, unsigned int optlen)
+{
+       struct sock_fprog __user *kfprog;
+
+       kfprog = get_compat_bpf_fprog(optval);
+       if (!kfprog)
                return -EFAULT;
 
        return sock_setsockopt(sock, level, optname, (char __user *)kfprog,