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From 13ec7f10b87f5fc04c4ccbd491c94c7980236a74 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Wed, 29 May 2019 14:52:19 +0200
Subject: [PATCH] mwifiex: Fix possible buffer overflows at parsing bss
 descriptor
References: bsc#1136424 CVE-2019-3846
Patch-mainline: v5.2-rc5
Git-commit: 13ec7f10b87f5fc04c4ccbd491c94c7980236a74

mwifiex_update_bss_desc_with_ie() calls memcpy() unconditionally in
a couple places without checking the destination size.  Since the
source is given from user-space, this may trigger a heap buffer
overflow.

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

This fix addresses CVE-2019-3846.

Reported-by: huangwen <huangwen@venustech.com.cn>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/net/wireless/marvell/mwifiex/scan.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/marvell/mwifiex/scan.c b/drivers/net/wireless/marvell/mwifiex/scan.c
index 935778ec9a1b..64ab6fe78c0d 100644
--- a/drivers/net/wireless/marvell/mwifiex/scan.c
+++ b/drivers/net/wireless/marvell/mwifiex/scan.c
@@ -1247,6 +1247,8 @@ int mwifiex_update_bss_desc_with_ie(struct mwifiex_adapter *adapter,
 		}
 		switch (element_id) {
 		case WLAN_EID_SSID:
+			if (element_len > IEEE80211_MAX_SSID_LEN)
+				return -EINVAL;
 			bss_entry->ssid.ssid_len = element_len;
 			memcpy(bss_entry->ssid.ssid, (current_ptr + 2),
 			       element_len);
@@ -1256,6 +1258,8 @@ int mwifiex_update_bss_desc_with_ie(struct mwifiex_adapter *adapter,
 			break;
 
 		case WLAN_EID_SUPP_RATES:
+			if (element_len > MWIFIEX_SUPPORTED_RATES)
+				return -EINVAL;
 			memcpy(bss_entry->data_rates, current_ptr + 2,
 			       element_len);
 			memcpy(bss_entry->supported_rates, current_ptr + 2,
-- 
2.16.4