DivestOS/Patches/Linux_CVEs/CVE-2017-0790/ANY/0.patch

From 5575ff40a53a954ec942ff0c17b193433e72c132 Mon Sep 17 00:00:00 2001
From: Sudhir Kohalli <sudhir.kohalli@broadcom.com>
Date: Wed, 14 Jun 2017 11:36:22 -0700
Subject: net: wireless: bcmdhd: add boundary check in GSCAN full result
 handler

validtating each length fields before not to overflow allocated
data type. it prevent possiblity heap memory corrupted.

Signed-off-by: Sudhir Kohalli <sudhir.kohalli@broadcom.com>
Bug: 37357704
Change-Id: I7c04b93f3843c8100bd932fb9b7c67ef76b93050
---
 drivers/net/wireless/bcmdhd/dhd_linux.c   |  5 +++--
 drivers/net/wireless/bcmdhd/dhd_pno.c     | 37 ++++++++++++++++++++++++-------
 drivers/net/wireless/bcmdhd/dhd_pno.h     |  7 +++---
 drivers/net/wireless/bcmdhd/wl_cfg80211.c |  7 ++++--
 4 files changed, 41 insertions(+), 15 deletions(-)

diff --git a/drivers/net/wireless/bcmdhd/dhd_linux.c b/drivers/net/wireless/bcmdhd/dhd_linux.c
index 0b66e91..abc4331 100644
--- a/drivers/net/wireless/bcmdhd/dhd_linux.c
+++ b/drivers/net/wireless/bcmdhd/dhd_linux.c
@@ -8420,11 +8420,12 @@ void * dhd_dev_hotlist_scan_event(struct net_device *dev,
 
 /* Linux wrapper to call common dhd_process_full_gscan_result */
 void * dhd_dev_process_full_gscan_result(struct net_device *dev,
-const void  *data, int *send_evt_bytes)
+const void  *data, uint32 len, int *send_evt_bytes)
 {
 	dhd_info_t *dhd = *(dhd_info_t **)netdev_priv(dev);
 
-	return (dhd_process_full_gscan_result(&dhd->pub, data, send_evt_bytes));
+	return dhd_process_full_gscan_result(&dhd->pub, data, len,
+			send_evt_bytes);
 }
 
 void dhd_dev_gscan_hotlist_cache_cleanup(struct net_device *dev, hotlist_type_t type)
diff --git a/drivers/net/wireless/bcmdhd/dhd_pno.c b/drivers/net/wireless/bcmdhd/dhd_pno.c
index c80adec..3103f89 100644
--- a/drivers/net/wireless/bcmdhd/dhd_pno.c
+++ b/drivers/net/wireless/bcmdhd/dhd_pno.c
@@ -47,6 +47,7 @@
 #ifdef GSCAN_SUPPORT
 #include <linux/gcd.h>
 #endif /* GSCAN_SUPPORT */
+#include <wl_cfg80211.h>
 
 #ifdef __BIG_ENDIAN
 #include <bcmendian.h>
@@ -3693,7 +3694,8 @@ void dhd_gscan_hotlist_cache_cleanup(dhd_pub_t *dhd, hotlist_type_t type)
 }
 
 void *
-dhd_process_full_gscan_result(dhd_pub_t *dhd, const void *data, int *size)
+dhd_process_full_gscan_result(dhd_pub_t *dhd, const void *data, uint32 len,
+			      int *size)
 {
 	wl_bss_info_t *bi = NULL;
 	wl_gscan_result_t *gscan_result;
@@ -3702,15 +3704,25 @@ dhd_process_full_gscan_result(dhd_pub_t *dhd, const void *data, int *size)
 	uint8 channel;
 	uint32 mem_needed;
 	struct timespec ts;
+	u32 bi_ie_length = 0;
+	u32 bi_ie_offset = 0;
 
 	*size = 0;
-
 	gscan_result = (wl_gscan_result_t *)data;
-
 	if (!gscan_result) {
 		DHD_ERROR(("Invalid gscan result (NULL pointer)\n"));
 		goto exit;
 	}
+
+	if ((len < sizeof(*gscan_result)) ||
+	    (len < dtoh32(gscan_result->buflen)) ||
+	    (dtoh32(gscan_result->buflen) >
+	    (sizeof(*gscan_result) + WL_SCAN_IE_LEN_MAX))) {
+		DHD_ERROR(("%s: invalid gscan buflen:%u\n", __func__,
+			   dtoh32(gscan_result->buflen)));
+		goto exit;
+	}
+
 	if (!gscan_result->bss_info) {
 		DHD_ERROR(("Invalid gscan bss info (NULL pointer)\n"));
 		goto exit;
@@ -3722,12 +3734,21 @@ dhd_process_full_gscan_result(dhd_pub_t *dhd, const void *data, int *size)
 		DHD_ERROR(("Invalid bss_info length %d: ignoring\n", bi_length));
 		goto exit;
 	}
+
+	bi_ie_offset = dtoh32(bi->ie_offset);
+	bi_ie_length = dtoh32(bi->ie_length);
+	if ((bi_ie_offset + bi_ie_length) > bi_length) {
+		DHD_ERROR(("%s: Invalid ie_length:%u or ie_offset:%u\n",
+			   __func__, bi_ie_length, bi_ie_offset));
+		goto exit;
+	}
 	if (bi->SSID_len > DOT11_MAX_SSID_LEN) {
-		DHD_ERROR(("Invalid SSID length %d: trimming it to max\n", bi->SSID_len));
-		bi->SSID_len = DOT11_MAX_SSID_LEN;
+		DHD_ERROR(("%s: Invalid SSID length %u\n",
+			   __func__, bi->SSID_len));
+		goto exit;
 	}
 
-	mem_needed = OFFSETOF(wifi_gscan_full_result_t, ie_data) + bi->ie_length;
+	mem_needed = OFFSETOF(wifi_gscan_full_result_t, ie_data) + bi_ie_length;
 	result = (wifi_gscan_full_result_t *) kmalloc(mem_needed, GFP_KERNEL);
 
 	if (!result) {
@@ -3749,9 +3770,9 @@ dhd_process_full_gscan_result(dhd_pub_t *dhd, const void *data, int *size)
 	result->fixed.ts = (uint64) TIMESPEC_TO_US(ts);
 	result->fixed.beacon_period = dtoh16(bi->beacon_period);
 	result->fixed.capability = dtoh16(bi->capability);
-	result->ie_length = dtoh32(bi->ie_length);
+	result->ie_length = bi_ie_length;
 	memcpy(&result->fixed.macaddr, &bi->BSSID, ETHER_ADDR_LEN);
-	memcpy(result->ie_data, ((uint8 *)bi + bi->ie_offset), bi->ie_length);
+	memcpy(result->ie_data, ((uint8 *)bi + bi_ie_offset), bi_ie_length);
 	*size = mem_needed;
 exit:
 	return result;
diff --git a/drivers/net/wireless/bcmdhd/dhd_pno.h b/drivers/net/wireless/bcmdhd/dhd_pno.h
index a0edf54..3398752 100644
--- a/drivers/net/wireless/bcmdhd/dhd_pno.h
+++ b/drivers/net/wireless/bcmdhd/dhd_pno.h
@@ -512,7 +512,7 @@ int dhd_retreive_batch_scan_results(dhd_pub_t *dhd);
 extern void * dhd_dev_hotlist_scan_event(struct net_device *dev,
                          const void  *data, int *send_evt_bytes, hotlist_type_t type);
 void * dhd_dev_process_full_gscan_result(struct net_device *dev,
-                                        const void  *data, int *send_evt_bytes);
+			const void  *data, uint32 len, int *send_evt_bytes);
 extern int dhd_dev_gscan_batch_cache_cleanup(struct net_device *dev);
 extern void dhd_dev_gscan_hotlist_cache_cleanup(struct net_device *dev, hotlist_type_t type);
 extern int dhd_dev_wait_batch_results_complete(struct net_device *dev);
@@ -563,8 +563,9 @@ extern int dhd_dev_retrieve_batch_scan(struct net_device *dev);
 extern void *dhd_handle_swc_evt(dhd_pub_t *dhd, const void *event_data, int *send_evt_bytes);
 extern void *dhd_handle_hotlist_scan_evt(dhd_pub_t *dhd, const void *event_data,
                        int *send_evt_bytes, hotlist_type_t type);
-extern void *dhd_process_full_gscan_result(dhd_pub_t *dhd, const void *event_data,
-                       int *send_evt_bytes);
+extern void *
+dhd_process_full_gscan_result(dhd_pub_t *dhd, const void *event_data,
+			      uint32 len, int *send_evt_bytes);
 extern int dhd_gscan_batch_cache_cleanup(dhd_pub_t *dhd);
 extern void dhd_gscan_hotlist_cache_cleanup(dhd_pub_t *dhd, hotlist_type_t type);
 extern int dhd_wait_batch_results_complete(dhd_pub_t *dhd);
diff --git a/drivers/net/wireless/bcmdhd/wl_cfg80211.c b/drivers/net/wireless/bcmdhd/wl_cfg80211.c
index d8c748d..1d1e2a8 100644
--- a/drivers/net/wireless/bcmdhd/wl_cfg80211.c
+++ b/drivers/net/wireless/bcmdhd/wl_cfg80211.c
@@ -9452,10 +9452,13 @@ wl_notify_gscan_event(struct bcm_cfg80211 *cfg, bcm_struct_cfgdev *cfgdev,
 				err = -EINVAL;
 			break;
 		case WLC_E_PFN_GSCAN_FULL_RESULT:
-			ptr = dhd_dev_process_full_gscan_result(ndev, data, &send_evt_bytes);
+			ptr =
+			dhd_dev_process_full_gscan_result(ndev, data, len,
+							  &send_evt_bytes);
 			if (ptr) {
 				wl_cfgvendor_send_async_event(wiphy, ndev,
-				    GOOGLE_SCAN_FULL_RESULTS_EVENT, ptr, send_evt_bytes);
+				    GOOGLE_SCAN_FULL_RESULTS_EVENT, ptr,
+				    send_evt_bytes);
 				kfree(ptr);
 			} else
 				err = -ENOMEM;
-- 
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