CVE-2019-14815: Heap-based Buffer Overflow (CWE-122)
value: A vulnerability was found in Linux Kernel, where a Heap Overflow was found in mwifiex_set_wmm_params() function of Marvell Wifi Driver.
CWE description: A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
CVSS v3 base score: 7.8
Published: 2019-11-25T11:15Z
Repository: https://github.com/torvalds/linux
Language: C
Files changed: drivers/net/wireless/marvell/mwifiex/ie.c, drivers/net/wireless/marvell/mwifiex/uap_cmd.c
Commit date: 2019-09-03 16:50:21 +0300
Commit message: mwifiex: Fix three heap overflow at parsing element in cfg80211_ap_settings

mwifiex_update_vs_ie(),mwifiex_set_uap_rates() and
mwifiex_set_wmm_params() call memcpy() without checking
the destination size.Since the source is given from
user-space, this may trigger a heap buffer overflow.

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

This fix addresses CVE-2019-14814,CVE-2019-14815,CVE-2019-14816.

Signed-off-by: Wen Huang <huangwenabc@gmail.com>
Acked-by: Ganapathi Bhat <gbhat@marvell.comg>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

Diff: diff --git a/drivers/net/wireless/marvell/mwifiex/ie.c b/drivers/net/wireless/marvell/mwifiex/ie.c
index 653d347a9a19..580387f9f12a 100644
--- a/drivers/net/wireless/marvell/mwifiex/ie.c
+++ b/drivers/net/wireless/marvell/mwifiex/ie.c
@@ -239,10 +239,13 @@ static int mwifiex_update_vs_ie(const u8 *ies, int ies_len,
 				return -ENOMEM;
 			ie = *ie_ptr;
 		}
 
 		vs_ie = (struct ieee_types_header *)vendor_ie;
+		if (le16_to_cpu(ie->ie_length) + vs_ie->len + 2 >
+			IEEE_MAX_IE_SIZE)
+			return -EINVAL;
 		memcpy(ie->ie_buffer + le16_to_cpu(ie->ie_length),
 		       vs_ie, vs_ie->len + 2);
 		le16_unaligned_add_cpu(&ie->ie_length, vs_ie->len + 2);
 		ie->mgmt_subtype_mask = cpu_to_le16(mask);
 		ie->ie_index = cpu_to_le16(MWIFIEX_AUTO_IDX_MASK);
diff --git a/drivers/net/wireless/marvell/mwifiex/uap_cmd.c b/drivers/net/wireless/marvell/mwifiex/uap_cmd.c
index 18f7d9bf30b2..0939a8c8f3ab 100644
--- a/drivers/net/wireless/marvell/mwifiex/uap_cmd.c
+++ b/drivers/net/wireless/marvell/mwifiex/uap_cmd.c
@@ -263,19 +263,24 @@ mwifiex_set_uap_rates(struct mwifiex_uap_bss_param *bss_cfg,
 	int len = params->beacon.head_len - var_offset;
 	u8 rate_len = 0;
 
 	rate_ie = (void *)cfg80211_find_ie(WLAN_EID_SUPP_RATES, var_pos, len);
 	if (rate_ie) {
+		if (rate_ie->len > MWIFIEX_SUPPORTED_RATES)
+			return;
 		memcpy(bss_cfg->rates, rate_ie + 1, rate_ie->len);
 		rate_len = rate_ie->len;
 	}
 
 	rate_ie = (void *)cfg80211_find_ie(WLAN_EID_EXT_SUPP_RATES,
 					   params->beacon.tail,
 					   params->beacon.tail_len);
-	if (rate_ie)
+	if (rate_ie) {
+		if (rate_ie->len > MWIFIEX_SUPPORTED_RATES - rate_len)
+			return;
 		memcpy(bss_cfg->rates + rate_len, rate_ie + 1, rate_ie->len);
+	}
 
 	return;
 }
 
 /* This function initializes some of mwifiex_uap_bss_param variables.
@@ -389,10 +394,12 @@ mwifiex_set_wmm_params(struct mwifiex_private *priv,
 					    WLAN_OUI_TYPE_MICROSOFT_WMM,
 					    params->beacon.tail,
 					    params->beacon.tail_len);
 	if (vendor_ie) {
 		wmm_ie = vendor_ie;
+		if (*(wmm_ie + 1) > sizeof(struct mwifiex_types_wmm_info))
+			return;
 		memcpy(&bss_cfg->wmm_info, wmm_ie +
 		       sizeof(struct ieee_types_header), *(wmm_ie + 1));
 		priv->wmm_enabled = 1;
 	} else {
 		memset(&bss_cfg->wmm_info, 0, sizeof(bss_cfg->wmm_info));

Vulnerable code: 	if (rate_ie)
Fixed code: 		if (le16_to_cpu(ie->ie_length) + vs_ie->len + 2 >
			IEEE_MAX_IE_SIZE)
			return -EINVAL;
		if (rate_ie->len > MWIFIEX_SUPPORTED_RATES)
			return;
	if (rate_ie) {
		if (rate_ie->len > MWIFIEX_SUPPORTED_RATES - rate_len)
			return;
	}
		if (*(wmm_ie + 1) > sizeof(struct mwifiex_types_wmm_info))
			return;