[PATCH 4.4 34/56] mwifiex: Fix three heap overflow at parsing element in cfg80211_ap_settings

[Greg Kroah-Hartman]

From: Wen Huang <huangwenabc@xxxxxxxxx>

commit 7caac62ed598a196d6ddf8d9c121e12e082cac3a upstream.

mwifiex_update_vs_ie(),mwifiex_set_uap_rates() and
mwifiex_set_wmm_params() call memcpy() without checking
the destination size.Since the source is given from
user-space, this may trigger a heap buffer overflow.

Fix them by putting the length check before performing memcpy().

This fix addresses CVE-2019-14814,CVE-2019-14815,CVE-2019-14816.

Signed-off-by: Wen Huang <huangwenabc@xxxxxxxxx>
Acked-by: Ganapathi Bhat <gbhat@xxxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/net/wireless/mwifiex/ie.c      |    3 +++
 drivers/net/wireless/mwifiex/uap_cmd.c |    9 ++++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

--- a/drivers/net/wireless/mwifiex/ie.c
+++ b/drivers/net/wireless/mwifiex/ie.c
@@ -240,6 +240,9 @@ static int mwifiex_update_vs_ie(const u8
 		}
 
 		vs_ie = (struct ieee_types_header *)vendor_ie;
+		if (le16_to_cpu(ie->ie_length) + vs_ie->len + 2 >
+			IEEE_MAX_IE_SIZE)
+			return -EINVAL;
 		memcpy(ie->ie_buffer + le16_to_cpu(ie->ie_length),
 		       vs_ie, vs_ie->len + 2);
 		le16_add_cpu(&ie->ie_length, vs_ie->len + 2);
--- a/drivers/net/wireless/mwifiex/uap_cmd.c
+++ b/drivers/net/wireless/mwifiex/uap_cmd.c
@@ -286,6 +286,8 @@ mwifiex_set_uap_rates(struct mwifiex_uap
 
 	rate_ie = (void *)cfg80211_find_ie(WLAN_EID_SUPP_RATES, var_pos, len);
 	if (rate_ie) {
+		if (rate_ie->len > MWIFIEX_SUPPORTED_RATES)
+			return;
 		memcpy(bss_cfg->rates, rate_ie + 1, rate_ie->len);
 		rate_len = rate_ie->len;
 	}
@@ -293,8 +295,11 @@ mwifiex_set_uap_rates(struct mwifiex_uap
 	rate_ie = (void *)cfg80211_find_ie(WLAN_EID_EXT_SUPP_RATES,
 					   params->beacon.tail,
 					   params->beacon.tail_len);
-	if (rate_ie)
+	if (rate_ie) {
+		if (rate_ie->len > MWIFIEX_SUPPORTED_RATES - rate_len)
+			return;
 		memcpy(bss_cfg->rates + rate_len, rate_ie + 1, rate_ie->len);
+	}
 
 	return;
 }
@@ -412,6 +417,8 @@ mwifiex_set_wmm_params(struct mwifiex_pr
 					    params->beacon.tail_len);
 	if (vendor_ie) {
 		wmm_ie = (struct ieee_types_header *)vendor_ie;
+		if (*(vendor_ie + 1) > sizeof(struct mwifiex_types_wmm_info))
+			return;
 		memcpy(&bss_cfg->wmm_info, wmm_ie + 1,
 		       sizeof(bss_cfg->wmm_info));
 		priv->wmm_enabled = 1;