linux-kernel - [PATCH 3.16 183/294] brcmfmac: add length check in brcmf_cfg80211_escan

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <lsq.1510009382.65778864@decadent.org.uk>
Date:   Mon, 06 Nov 2017 23:03:02 +0000
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org,
        "Arend Van Spriel" <arend.vanspriel@...adcom.com>,
        "Kevin Cernekee" <cernekee@...omium.org>,
        "Pieter-Paul Giesberts" <pieter-paul.giesberts@...adcom.com>,
        "Franky Lin" <franky.lin@...adcom.com>,
        "Hante Meuleman" <hante.meuleman@...adcom.com>,
        "Kalle Valo" <kvalo@...eaurora.org>
Subject: [PATCH 3.16 183/294] brcmfmac: add length check in
 brcmf_cfg80211_escan_handler()

3.16.50-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Arend Van Spriel <arend.vanspriel@...adcom.com>

commit 17df6453d4be17910456e99c5a85025aa1b7a246 upstream.

Upon handling the firmware notification for scans the length was
checked properly and may result in corrupting kernel heap memory
due to buffer overruns. This fix addresses CVE-2017-0786.

Cc: Kevin Cernekee <cernekee@...omium.org>
Reviewed-by: Hante Meuleman <hante.meuleman@...adcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@...adcom.com>
Reviewed-by: Franky Lin <franky.lin@...adcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@...adcom.com>
Signed-off-by: Kalle Valo <kvalo@...eaurora.org>
[bwh: Backported to 3.16:
 - Use WL_ESCAN_BUF_SIZE instead of BRCMF_ESCAN_BUF_SIZE
 - Adjust filename]
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 .../wireless/brcm80211/brcmfmac/wl_cfg80211.c    | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

--- a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
@@ -2692,6 +2692,7 @@ brcmf_cfg80211_escan_handler(struct brcm
 	s32 status;
 	s32 err = 0;
 	struct brcmf_escan_result_le *escan_result_le;
+	u32 escan_buflen;
 	struct brcmf_bss_info_le *bss_info_le;
 	struct brcmf_bss_info_le *bss = NULL;
 	u32 bi_length;
@@ -2708,11 +2709,23 @@ brcmf_cfg80211_escan_handler(struct brcm
 
 	if (status == BRCMF_E_STATUS_PARTIAL) {
 		brcmf_dbg(SCAN, "ESCAN Partial result\n");
+		if (e->datalen < sizeof(*escan_result_le)) {
+			brcmf_err("invalid event data length\n");
+			goto exit;
+		}
 		escan_result_le = (struct brcmf_escan_result_le *) data;
 		if (!escan_result_le) {
 			brcmf_err("Invalid escan result (NULL pointer)\n");
 			goto exit;
 		}
+		escan_buflen = le32_to_cpu(escan_result_le->buflen);
+		if (escan_buflen > WL_ESCAN_BUF_SIZE ||
+		    escan_buflen > e->datalen ||
+		    escan_buflen < sizeof(*escan_result_le)) {
+			brcmf_err("Invalid escan buffer length: %d\n",
+				  escan_buflen);
+			goto exit;
+		}
 		if (le16_to_cpu(escan_result_le->bss_count) != 1) {
 			brcmf_err("Invalid bss_count %d: ignoring\n",
 				  escan_result_le->bss_count);
@@ -2729,9 +2742,8 @@ brcmf_cfg80211_escan_handler(struct brcm
 		}
 
 		bi_length = le32_to_cpu(bss_info_le->length);
-		if (bi_length != (le32_to_cpu(escan_result_le->buflen) -
-					WL_ESCAN_RESULTS_FIXED_SIZE)) {
-			brcmf_err("Invalid bss_info length %d: ignoring\n",
+		if (bi_length != escan_buflen -	WL_ESCAN_RESULTS_FIXED_SIZE) {
+			brcmf_err("Ignoring invalid bss_info length: %d\n",
 				  bi_length);
 			goto exit;
 		}