Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, huangwen <huangwen@venustech.com.cn>,
        Takashi Iwai <tiwai@suse.de>,
        Kalle Valo <kvalo@codeaurora.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.14 13/80] mwifiex: Fix possible buffer overflows at parsing bss descriptor
Date:   Thu, 18 Jul 2019 12:01:04 +0900
Message-Id: <20190718030059.856460093@linuxfoundation.org>
In-Reply-To: <20190718030058.615992480@linuxfoundation.org>
References: <20190718030058.615992480@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

[ Upstream 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: Sasha Levin <sashal@kernel.org>
---
 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 c9d41ed77fc7..c08a4574c396 100644
--- a/drivers/net/wireless/marvell/mwifiex/scan.c
+++ b/drivers/net/wireless/marvell/mwifiex/scan.c
@@ -1244,6 +1244,8 @@ 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);
@@ -1253,6 +1255,8 @@ 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,
-- 
2.20.1