| Message ID | 20191004095132.15777-2-will@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Johannes Berg |
| Headers | show |
| Series | [1/2] mac80211: Reject malformed SSID elements | expand |
On Fri, Oct 04, 2019 at 10:51:32AM +0100, Will Deacon wrote: > Ensure the SSID element is bounds-checked prior to invoking memcpy() > with its length field. > > Cc: <stable@vger.kernel.org> > Cc: Johannes Berg <johannes@sipsolutions.net> > Cc: Kees Cook <keescook@chromium.org> > Reported-by: Nicolas Waisman <nico@semmle.com> > Signed-off-by: Will Deacon <will@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> -Kees > --- > net/wireless/wext-sme.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/net/wireless/wext-sme.c b/net/wireless/wext-sme.c > index c67d7a82ab13..3fd2cc7fc36a 100644 > --- a/net/wireless/wext-sme.c > +++ b/net/wireless/wext-sme.c > @@ -201,6 +201,7 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev, > struct iw_request_info *info, > struct iw_point *data, char *ssid) > { > + int ret = 0; > struct wireless_dev *wdev = dev->ieee80211_ptr; > > /* call only for station! */ > @@ -219,7 +220,10 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev, > if (ie) { > data->flags = 1; > data->length = ie[1]; > - memcpy(ssid, ie + 2, data->length); > + if (data->length > IW_ESSID_MAX_SIZE) > + ret = -EINVAL; > + else > + memcpy(ssid, ie + 2, data->length); > } > rcu_read_unlock(); > } else if (wdev->wext.connect.ssid && wdev->wext.connect.ssid_len) { > @@ -229,7 +233,7 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev, > } > wdev_unlock(wdev); > > - return 0; > + return ret; > } > > int cfg80211_mgd_wext_siwap(struct net_device *dev, > -- > 2.23.0.581.g78d2f28ef7-goog >
diff --git a/net/wireless/wext-sme.c b/net/wireless/wext-sme.c index c67d7a82ab13..3fd2cc7fc36a 100644 --- a/net/wireless/wext-sme.c +++ b/net/wireless/wext-sme.c @@ -201,6 +201,7 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev, struct iw_request_info *info, struct iw_point *data, char *ssid) { + int ret = 0; struct wireless_dev *wdev = dev->ieee80211_ptr; /* call only for station! */ @@ -219,7 +220,10 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev, if (ie) { data->flags = 1; data->length = ie[1]; - memcpy(ssid, ie + 2, data->length); + if (data->length > IW_ESSID_MAX_SIZE) + ret = -EINVAL; + else + memcpy(ssid, ie + 2, data->length); } rcu_read_unlock(); } else if (wdev->wext.connect.ssid && wdev->wext.connect.ssid_len) { @@ -229,7 +233,7 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev, } wdev_unlock(wdev); - return 0; + return ret; } int cfg80211_mgd_wext_siwap(struct net_device *dev,
Ensure the SSID element is bounds-checked prior to invoking memcpy() with its length field. Cc: <stable@vger.kernel.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kees Cook <keescook@chromium.org> Reported-by: Nicolas Waisman <nico@semmle.com> Signed-off-by: Will Deacon <will@kernel.org> --- net/wireless/wext-sme.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)