[PATCH 4.1 122/127] staging: lustre: echo_copy.._lsm() dereferences userland pointers directly

From: Greg Kroah-Hartman
Date: Wed Jan 27 2016 - 14:37:59 EST


4.1-stable review patch. If anyone has any objections, please let me know.

------------------

From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

commit 9225c0b7b976dd9ceac2b80727a60d8fcb906a62 upstream.

missing get_user()

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/staging/lustre/lustre/obdecho/echo_client.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)

--- a/drivers/staging/lustre/lustre/obdecho/echo_client.c
+++ b/drivers/staging/lustre/lustre/obdecho/echo_client.c
@@ -1268,6 +1268,7 @@ 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]);
@@ -1277,9 +1278,10 @@ echo_copyout_lsm(struct lov_stripe_md *l
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;
@@ -1287,9 +1289,10 @@ echo_copyout_lsm(struct lov_stripe_md *l

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))
@@ -1305,11 +1308,10 @@ echo_copyin_lsm(struct echo_device *ed,
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;