net: switch importing msghdr from userland to {compat_,}import_iovec()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 19 insertions, 30 deletions

diff --git a/net/compat.c b/net/compat.c
index c4b6b0f43d5d..5cfd26a0006f 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -31,10 +31,10 @@
 #include <asm/uaccess.h>
 #include <net/compat.h>
 
-ssize_t get_compat_msghdr(struct msghdr *kmsg,
-                          struct compat_msghdr __user *umsg,
-                          struct sockaddr __user **save_addr,
-                          struct iovec **iov)
+int get_compat_msghdr(struct msghdr *kmsg,
+                      struct compat_msghdr __user *umsg,
+                      struct sockaddr __user **save_addr,
+                      struct iovec **iov)
 {
         compat_uptr_t uaddr, uiov, tmp3;
         compat_size_t nr_segs;
@@ -81,13 +81,9 @@ ssize_t get_compat_msghdr(struct msghdr *kmsg,
 
         kmsg->msg_iocb = NULL;
 
-        err = compat_rw_copy_check_uvector(save_addr ? READ : WRITE,
-                                           compat_ptr(uiov), nr_segs,
-                                           UIO_FASTIOV, *iov, iov);
-        if (err >= 0)
-                iov_iter_init(&kmsg->msg_iter, save_addr ? READ : WRITE,
-                              *iov, nr_segs, err);
-        return err;
+        return compat_import_iovec(save_addr ? READ : WRITE,
+                                   compat_ptr(uiov), nr_segs,
+                                   UIO_FASTIOV, iov, &kmsg->msg_iter);
 }
 
 /* Bleech... */
diff --git a/net/socket.c b/net/socket.c
index 46f0e1d752b3..e5669cee0759 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1841,10 +1841,10 @@ struct used_address {
         unsigned int name_len;
 };
 
-static ssize_t copy_msghdr_from_user(struct msghdr *kmsg,
-                                     struct user_msghdr __user *umsg,
-                                     struct sockaddr __user **save_addr,
-                                     struct iovec **iov)
+static int copy_msghdr_from_user(struct msghdr *kmsg,
+                                 struct user_msghdr __user *umsg,
+                                 struct sockaddr __user **save_addr,
+                                 struct iovec **iov)
 {
         struct sockaddr __user *uaddr;
         struct iovec __user *uiov;
@@ -1890,13 +1890,8 @@ static ssize_t copy_msghdr_from_user(struct msghdr *kmsg,
 
         kmsg->msg_iocb = NULL;
 
-        err = rw_copy_check_uvector(save_addr ? READ : WRITE,
-                                    uiov, nr_segs,
-                                    UIO_FASTIOV, *iov, iov);
-        if (err >= 0)
-                iov_iter_init(&kmsg->msg_iter, save_addr ? READ : WRITE,
-                              *iov, nr_segs, err);
-        return err;
+        return import_iovec(save_addr ? READ : WRITE, uiov, nr_segs,
+                            UIO_FASTIOV, iov, &kmsg->msg_iter);
 }
 
 static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
@@ -1921,8 +1916,8 @@ static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
         else
                 err = copy_msghdr_from_user(msg_sys, msg, NULL, &iov);
         if (err < 0)
-                goto out_freeiov;
-        total_len = err;
+                return err;
+        total_len = iov_iter_count(&msg_sys->msg_iter);
 
         err = -ENOBUFS;
 
@@ -1988,8 +1983,7 @@ out_freectl:
         if (ctl_buf != ctl)
                 sock_kfree_s(sock->sk, ctl_buf, ctl_len);
 out_freeiov:
-        if (iov != iovstack)
-                kfree(iov);
+        kfree(iov);
         return err;
 }
 
@@ -2114,8 +2108,8 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
         else
                 err = copy_msghdr_from_user(msg_sys, msg, &uaddr, &iov);
         if (err < 0)
-                goto out_freeiov;
-        total_len = err;
+                return err;
+        total_len = iov_iter_count(&msg_sys->msg_iter);
 
         cmsg_ptr = (unsigned long)msg_sys->msg_control;
         msg_sys->msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
@@ -2153,8 +2147,7 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
         err = len;
 
 out_freeiov:
-        if (iov != iovstack)
-                kfree(iov);
+        kfree(iov);
         return err;
 }