staging: wlags49_h2: buffer overflow setting station name

We need to check the length parameter before doing the memcpy().  I've
actually changed it to strlcpy() as well so that it's NUL terminated.

You need CAP_NET_ADMIN to trigger these so it's not the end of the
world.

Reported-by: Nico Golde <nico@ngolde.de>
Reported-by: Fabian Yamaguchi <fabs@goesec.de>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/staging/wlags49_h2/wl_priv.c b/drivers/staging/wlags49_h2/wl_priv.c
index c97e0e154d28..7e10dcdc3090 100644
--- a/drivers/staging/wlags49_h2/wl_priv.c
+++ b/drivers/staging/wlags49_h2/wl_priv.c
@@ -570,6 +570,7 @@ int wvlan_uil_put_info(struct uilreq *urq, struct wl_private *lp)
         ltv_t                   *pLtv;
         bool_t                  ltvAllocated = FALSE;
         ENCSTRCT                sEncryption;
+        size_t                  len;
 
 #ifdef USE_WDS
         hcf_16                  hcfPort  = HCF_PORT_0;
@@ -686,7 +687,8 @@ int wvlan_uil_put_info(struct uilreq *urq, struct wl_private *lp)
                                         break;
                                 case CFG_CNF_OWN_NAME:
                                         memset(lp->StationName, 0, sizeof(lp->StationName));
-                                        memcpy((void *)lp->StationName, (void *)&pLtv->u.u8[2], (size_t)pLtv->u.u16[0]);
+                                        len = min_t(size_t, pLtv->u.u16[0], sizeof(lp->StationName));
+                                        strlcpy(lp->StationName, &pLtv->u.u8[2], len);
                                         pLtv->u.u16[0] = CNV_INT_TO_LITTLE(pLtv->u.u16[0]);
                                         break;
                                 case CFG_CNF_LOAD_BALANCING:
@@ -1783,6 +1785,7 @@ int wvlan_set_station_nickname(struct net_device *dev,
 {
         struct wl_private *lp = wl_priv(dev);
         unsigned long flags;
+        size_t len;
         int         ret = 0;
         /*------------------------------------------------------------------------*/
 
@@ -1793,8 +1796,8 @@ int wvlan_set_station_nickname(struct net_device *dev,
         wl_lock(lp, &flags);
 
         memset(lp->StationName, 0, sizeof(lp->StationName));
-
-        memcpy(lp->StationName, extra, wrqu->data.length);
+        len = min_t(size_t, wrqu->data.length, sizeof(lp->StationName));
+        strlcpy(lp->StationName, extra, len);
 
         /* Commit the adapter parameters */
         wl_apply(lp);