staging: wlags49_h2: buffer overflow setting station name

commit b5e2f339865fb443107e5b10603e53bbc92dc054 upstream.

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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/staging/wlags49_h2/wl_priv.c b/drivers/staging/wlags49_h2/wl_priv.c
index 260d4f0..b3d2e17 100644 (file)
--- 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:
@@ -1800,6 +1802,7 @@ 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;
        /*------------------------------------------------------------------------*/
 
@@ -1810,8 +1813,8 @@ 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 );