Subject: [PATCH AUTOSEL 4.4 088/100] mwifiex: Fix possible buffer overflows in mwifiex_ret_wmm_get_status()

From: Sasha Levin <[email-masked]>
Date: Fri, 14 Feb 2020 11:24:12 -0500

From: Qing Xu <[email-masked]>

[ Upstream commit 3a9b153c5591548612c3955c9600a98150c81875 ]

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 <[email-masked]>
Signed-off-by: Kalle Valo <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/wireless/mwifiex/wmm.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/mwifiex/wmm.c b/drivers/net/wireless/mwifiex/wmm.c
index 7015dfab49cfc..3a2ecb6cf1c3d 100644
--- a/drivers/net/wireless/mwifiex/wmm.c
+++ b/drivers/net/wireless/mwifiex/wmm.c
@@ -978,6 +978,10 @@ int mwifiex_ret_wmm_get_status(struct mwifiex_private *priv,
 				    "WMM Parameter Set Count: %d\n",
 				    wmm_param_ie->qos_info_bitmap & 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);
-- 
2.20.1