[PATCH for-4.14 0/2] brcmfmac: scan related fixes

[PATCH for-4.14 0/2] brcmfmac: scan related fixes

[Arend van Spriel]

Two patches related to scanning functionality in the driver. The first
patch addresses a security vulnerability in firmware notification
handling. The second one fixes a reported API issue in which the driver
ignored a passive scan request from user-space.

The patches apply to the master branch of the wireless-drivers
repository.

Arend van Spriel (2):
  brcmfmac: add length check in brcmf_cfg80211_escan_handler()
  brcmfmac: setup passive scan if requested by user-space

 .../broadcom/brcm80211/brcmfmac/cfg80211.c         | 37 +++++++++++-----------
 .../broadcom/brcm80211/brcmfmac/fwil_types.h       |  5 +++
 2 files changed, 24 insertions(+), 18 deletions(-)

-- 
1.9.1

[PATCH for-4.14 1/2] brcmfmac: add length check in brcmf_cfg80211_escan_handler()

[Arend van Spriel]

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: stable@vger.kernel.org # v4.0.x
Cc: Kevin Cernekee <cernekee@chromium.org>
Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
---
 .../wireless/broadcom/brcm80211/brcmfmac/cfg80211.c    | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
index aaed4ab..26a0de3 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
@@ -3162,6 +3162,7 @@ static void brcmf_escan_timeout(unsigned long data)
 	struct brcmf_cfg80211_info *cfg = ifp->drvr->config;
 	s32 status;
 	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;
@@ -3181,11 +3182,23 @@ static void brcmf_escan_timeout(unsigned long data)
 
 	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 > BRCMF_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);
@@ -3202,9 +3215,8 @@ static void brcmf_escan_timeout(unsigned long data)
 		}
 
 		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;
 		}
-- 
1.9.1

Re: [for-4.14, 1/2] brcmfmac: add length check in brcmf_cfg80211_escan_handler()

[Kalle Valo]

Arend Van Spriel <arend.vanspriel@broadcom.com> wrote:

> 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: stable@vger.kernel.org # v4.0.x
> Cc: Kevin Cernekee <cernekee@chromium.org>
> Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
> Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
> Reviewed-by: Franky Lin <franky.lin@broadcom.com>
> Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>

2 patches applied to wireless-drivers.git, thanks.

17df6453d4be brcmfmac: add length check in brcmf_cfg80211_escan_handler()
35f62727df0e brcmfmac: setup passive scan if requested by user-space

-- 
https://patchwork.kernel.org/patch/9948689/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

[PATCH for-4.14 2/2] brcmfmac: setup passive scan if requested by user-space

[Arend van Spriel]

The driver was not properly configuring firmware with regard to the
type of scan. It always performed an active scan even when user-space
was requesting for passive scan, ie. the scan request was done without
any SSIDs specified.

Cc: stable@vger.kernel.org # v4.0.x
Reported-by: Huang, Jiangyang <Jiangyang.Huang@itron.com>
Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
---
 .../wireless/broadcom/brcm80211/brcmfmac/cfg80211.c   | 19 ++++---------------
 .../wireless/broadcom/brcm80211/brcmfmac/fwil_types.h |  5 +++++
 2 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
index 26a0de3..4157c90 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
@@ -980,7 +980,7 @@ static void brcmf_escan_prep(struct brcmf_cfg80211_info *cfg,
 
 	eth_broadcast_addr(params_le->bssid);
 	params_le->bss_type = DOT11_BSSTYPE_ANY;
-	params_le->scan_type = 0;
+	params_le->scan_type = BRCMF_SCANTYPE_ACTIVE;
 	params_le->channel_num = 0;
 	params_le->nprobes = cpu_to_le32(-1);
 	params_le->active_time = cpu_to_le32(-1);
@@ -988,12 +988,9 @@ static void brcmf_escan_prep(struct brcmf_cfg80211_info *cfg,
 	params_le->home_time = cpu_to_le32(-1);
 	memset(&params_le->ssid_le, 0, sizeof(params_le->ssid_le));
 
-	/* if request is null exit so it will be all channel broadcast scan */
-	if (!request)
-		return;
-
 	n_ssids = request->n_ssids;
 	n_channels = request->n_channels;
+
 	/* Copy channel array if applicable */
 	brcmf_dbg(SCAN, "### List of channelspecs to scan ### %d\n",
 		  n_channels);
@@ -1030,16 +1027,8 @@ static void brcmf_escan_prep(struct brcmf_cfg80211_info *cfg,
 			ptr += sizeof(ssid_le);
 		}
 	} else {
-		brcmf_dbg(SCAN, "Broadcast scan %p\n", request->ssids);
-		if ((request->ssids) && request->ssids->ssid_len) {
-			brcmf_dbg(SCAN, "SSID %s len=%d\n",
-				  params_le->ssid_le.SSID,
-				  request->ssids->ssid_len);
-			params_le->ssid_le.SSID_len =
-				cpu_to_le32(request->ssids->ssid_len);
-			memcpy(&params_le->ssid_le.SSID, request->ssids->ssid,
-				request->ssids->ssid_len);
-		}
+		brcmf_dbg(SCAN, "Performing passive scan\n");
+		params_le->scan_type = BRCMF_SCANTYPE_PASSIVE;
 	}
 	/* Adding mask to channel numbers */
 	params_le->channel_num =
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h
index 8391989..e0d22fe 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h
@@ -45,6 +45,11 @@
 #define BRCMF_SCAN_PARAMS_COUNT_MASK	0x0000ffff
 #define BRCMF_SCAN_PARAMS_NSSID_SHIFT	16
 
+/* scan type definitions */
+#define BRCMF_SCANTYPE_DEFAULT		0xFF
+#define BRCMF_SCANTYPE_ACTIVE		0
+#define BRCMF_SCANTYPE_PASSIVE		1
+
 #define BRCMF_WSEC_MAX_PSK_LEN		32
 #define	BRCMF_WSEC_PASSPHRASE		BIT(0)
 
-- 
1.9.1