mwifiex: Fix possible buffer overflows in mwifiex_ret_wmm_get_status()

commit 3a9b153c5591548612c3955c9600a98150c81875 upstream.

mwifiex_ret_wmm_get_status() calls memcpy() without checking the
destination size.Since the source is given from remote AP which
contains illegal wmm elements , this may trigger a heap buffer
overflow.
Fix it by putting the length check before calling memcpy().

Signed-off-by: Qing Xu <m1s5p6688@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/net/wireless/mwifiex/wmm.c b/drivers/net/wireless/mwifiex/wmm.c
index 67cefd06b7b028ac0d1c91c450db2b7c1158cdcb..00b2cb7eb60bf01c0ec6600826557f5bab8a040e 100644 (file)
--- a/drivers/net/wireless/mwifiex/wmm.c
+++ b/drivers/net/wireless/mwifiex/wmm.c
@@ -791,6 +791,10 @@ int mwifiex_ret_wmm_get_status(struct mwifiex_private *priv,
                                wmm_param_ie->qos_info_bitmap &
                                IEEE80211_WMM_IE_AP_QOSINFO_PARAM_SET_CNT_MASK);
 
+                       if (wmm_param_ie->vend_hdr.len + 2 >
+                               sizeof(struct ieee_types_wmm_parameter))
+                               break;
+
                        memcpy((u8 *) &priv->curr_bss_params.bss_descriptor.
                               wmm_ie, wmm_param_ie,
                               wmm_param_ie->vend_hdr.len + 2);