staging: lustre: echo_copy.._lsm() dereferences userland pointers directly

commit 9225c0b7b976dd9ceac2b80727a60d8fcb906a62 upstream.

missing get_user()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

diff --git a/drivers/staging/lustre/lustre/obdecho/echo_client.c b/drivers/staging/lustre/lustre/obdecho/echo_client.c
index cdc46719bbd47aabcb81beee5097ed60e39ca986..95c0bdb45d2ac6c26c1627907c4a7e2120cf6ff5 100644 (file)
--- a/drivers/staging/lustre/lustre/obdecho/echo_client.c
+++ b/drivers/staging/lustre/lustre/obdecho/echo_client.c
@@ -1380,6 +1380,7 @@ static int
 echo_copyout_lsm (struct lov_stripe_md *lsm, void *_ulsm, int ulsm_nob)
 {
        struct lov_stripe_md *ulsm = _ulsm;
+       struct lov_oinfo **p;
        int nob, i;
 
        nob = offsetof (struct lov_stripe_md, lsm_oinfo[lsm->lsm_stripe_count]);
@@ -1389,9 +1390,10 @@ echo_copyout_lsm (struct lov_stripe_md *lsm, void *_ulsm, int ulsm_nob)
        if (copy_to_user (ulsm, lsm, sizeof(*ulsm)))
                return (-EFAULT);
 
-       for (i = 0; i < lsm->lsm_stripe_count; i++) {
-               if (copy_to_user (ulsm->lsm_oinfo[i], lsm->lsm_oinfo[i],
-                                     sizeof(lsm->lsm_oinfo[0])))
+       for (i = 0, p = lsm->lsm_oinfo; i < lsm->lsm_stripe_count; i++, p++) {
+               struct lov_oinfo __user *up;
+               if (get_user(up, ulsm->lsm_oinfo + i) ||
+                   copy_to_user(up, *p, sizeof(struct lov_oinfo)))
                        return (-EFAULT);
        }
        return 0;
@@ -1399,9 +1401,10 @@ echo_copyout_lsm (struct lov_stripe_md *lsm, void *_ulsm, int ulsm_nob)
 
 static int
 echo_copyin_lsm (struct echo_device *ed, struct lov_stripe_md *lsm,
-                void *ulsm, int ulsm_nob)
+               struct lov_stripe_md __user *ulsm, int ulsm_nob)
 {
        struct echo_client_obd *ec = ed->ed_ec;
+       struct lov_oinfo **p;
        int                  i;
 
        if (ulsm_nob < sizeof (*lsm))
@@ -1417,11 +1420,10 @@ echo_copyin_lsm (struct echo_device *ed, struct lov_stripe_md *lsm,
                return (-EINVAL);
 
 
-       for (i = 0; i < lsm->lsm_stripe_count; i++) {
-               if (copy_from_user(lsm->lsm_oinfo[i],
-                                      ((struct lov_stripe_md *)ulsm)-> \
-                                      lsm_oinfo[i],
-                                      sizeof(lsm->lsm_oinfo[0])))
+       for (i = 0, p = lsm->lsm_oinfo; i < lsm->lsm_stripe_count; i++, p++) {
+               struct lov_oinfo __user *up;
+               if (get_user(up, ulsm->lsm_oinfo + i) ||
+                   copy_from_user(*p, up, sizeof(struct lov_oinfo)))
                        return (-EFAULT);
        }
        return (0);