From 13ec7f10b87f5fc04c4ccbd491c94c7980236a74 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 29 May 2019 14:52:19 +0200 Subject: mwifiex: Fix possible buffer overflows at parsing bss descriptor 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 Signed-off-by: Takashi Iwai Signed-off-by: Kalle Valo --- drivers/net/wireless/marvell/mwifiex/scan.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/net/wireless/marvell') diff --git a/drivers/net/wireless/marvell/mwifiex/scan.c b/drivers/net/wireless/marvell/mwifiex/scan.c index 935778ec9a1b..64ab6fe78c0d 100644 --- a/drivers/net/wireless/marvell/mwifiex/scan.c +++ b/drivers/net/wireless/marvell/mwifiex/scan.c @@ -1247,6 +1247,8 @@ 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); @@ -1256,6 +1258,8 @@ 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, -- cgit v1.2.3 From 685c9b7750bfacd6fc1db50d86579980593b7869 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 29 May 2019 14:52:20 +0200 Subject: mwifiex: Abort at too short BSS descriptor element Currently mwifiex_update_bss_desc_with_ie() implicitly assumes that the source descriptor entries contain the enough size for each type and performs copying without checking the source size. This may lead to read over boundary. Fix this by putting the source size check in appropriate places. Signed-off-by: Takashi Iwai Signed-off-by: Kalle Valo --- drivers/net/wireless/marvell/mwifiex/scan.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'drivers/net/wireless/marvell') diff --git a/drivers/net/wireless/marvell/mwifiex/scan.c b/drivers/net/wireless/marvell/mwifiex/scan.c index 64ab6fe78c0d..c269a0de9413 100644 --- a/drivers/net/wireless/marvell/mwifiex/scan.c +++ b/drivers/net/wireless/marvell/mwifiex/scan.c @@ -1269,6 +1269,8 @@ int mwifiex_update_bss_desc_with_ie(struct mwifiex_adapter *adapter, break; case WLAN_EID_FH_PARAMS: + if (element_len + 2 < sizeof(*fh_param_set)) + return -EINVAL; fh_param_set = (struct ieee_types_fh_param_set *) current_ptr; memcpy(&bss_entry->phy_param_set.fh_param_set, @@ -1277,6 +1279,8 @@ int mwifiex_update_bss_desc_with_ie(struct mwifiex_adapter *adapter, break; case WLAN_EID_DS_PARAMS: + if (element_len + 2 < sizeof(*ds_param_set)) + return -EINVAL; ds_param_set = (struct ieee_types_ds_param_set *) current_ptr; @@ -1288,6 +1292,8 @@ int mwifiex_update_bss_desc_with_ie(struct mwifiex_adapter *adapter, break; case WLAN_EID_CF_PARAMS: + if (element_len + 2 < sizeof(*cf_param_set)) + return -EINVAL; cf_param_set = (struct ieee_types_cf_param_set *) current_ptr; memcpy(&bss_entry->ss_param_set.cf_param_set, @@ -1296,6 +1302,8 @@ int mwifiex_update_bss_desc_with_ie(struct mwifiex_adapter *adapter, break; case WLAN_EID_IBSS_PARAMS: + if (element_len + 2 < sizeof(*ibss_param_set)) + return -EINVAL; ibss_param_set = (struct ieee_types_ibss_param_set *) current_ptr; @@ -1305,10 +1313,14 @@ int mwifiex_update_bss_desc_with_ie(struct mwifiex_adapter *adapter, break; case WLAN_EID_ERP_INFO: + if (!element_len) + return -EINVAL; bss_entry->erp_flags = *(current_ptr + 2); break; case WLAN_EID_PWR_CONSTRAINT: + if (!element_len) + return -EINVAL; bss_entry->local_constraint = *(current_ptr + 2); bss_entry->sensed_11h = true; break; @@ -1349,6 +1361,9 @@ int mwifiex_update_bss_desc_with_ie(struct mwifiex_adapter *adapter, break; case WLAN_EID_VENDOR_SPECIFIC: + if (element_len + 2 < sizeof(vendor_ie->vend_hdr)) + return -EINVAL; + vendor_ie = (struct ieee_types_vendor_specific *) current_ptr; -- cgit v1.2.3 From 69ae4f6aac1578575126319d3f55550e7e440449 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Fri, 31 May 2019 15:18:41 +0200 Subject: mwifiex: Fix heap overflow in mwifiex_uap_parse_tail_ies() A few places in mwifiex_uap_parse_tail_ies() perform memcpy() unconditionally, which may lead to either buffer overflow or read over boundary. This patch addresses the issues by checking the read size and the destination size at each place more properly. Along with the fixes, the patch cleans up the code slightly by introducing a temporary variable for the token size, and unifies the error path with the standard goto statement. Reported-by: huangwen Signed-off-by: Takashi Iwai Signed-off-by: Kalle Valo --- drivers/net/wireless/marvell/mwifiex/ie.c | 47 ++++++++++++++++++++----------- 1 file changed, 31 insertions(+), 16 deletions(-) (limited to 'drivers/net/wireless/marvell') diff --git a/drivers/net/wireless/marvell/mwifiex/ie.c b/drivers/net/wireless/marvell/mwifiex/ie.c index 6845eb57b39a..653d347a9a19 100644 --- a/drivers/net/wireless/marvell/mwifiex/ie.c +++ b/drivers/net/wireless/marvell/mwifiex/ie.c @@ -329,6 +329,8 @@ static int mwifiex_uap_parse_tail_ies(struct mwifiex_private *priv, struct ieee80211_vendor_ie *vendorhdr; u16 gen_idx = MWIFIEX_AUTO_IDX_MASK, ie_len = 0; int left_len, parsed_len = 0; + unsigned int token_len; + int err = 0; if (!info->tail || !info->tail_len) return 0; @@ -344,6 +346,12 @@ static int mwifiex_uap_parse_tail_ies(struct mwifiex_private *priv, */ while (left_len > sizeof(struct ieee_types_header)) { hdr = (void *)(info->tail + parsed_len); + token_len = hdr->len + sizeof(struct ieee_types_header); + if (token_len > left_len) { + err = -EINVAL; + goto out; + } + switch (hdr->element_id) { case WLAN_EID_SSID: case WLAN_EID_SUPP_RATES: @@ -361,17 +369,20 @@ static int mwifiex_uap_parse_tail_ies(struct mwifiex_private *priv, if (cfg80211_find_vendor_ie(WLAN_OUI_MICROSOFT, WLAN_OUI_TYPE_MICROSOFT_WMM, (const u8 *)hdr, - hdr->len + sizeof(struct ieee_types_header))) + token_len)) break; /* fall through */ default: - memcpy(gen_ie->ie_buffer + ie_len, hdr, - hdr->len + sizeof(struct ieee_types_header)); - ie_len += hdr->len + sizeof(struct ieee_types_header); + if (ie_len + token_len > IEEE_MAX_IE_SIZE) { + err = -EINVAL; + goto out; + } + memcpy(gen_ie->ie_buffer + ie_len, hdr, token_len); + ie_len += token_len; break; } - left_len -= hdr->len + sizeof(struct ieee_types_header); - parsed_len += hdr->len + sizeof(struct ieee_types_header); + left_len -= token_len; + parsed_len += token_len; } /* parse only WPA vendor IE from tail, WMM IE is configured by @@ -381,15 +392,17 @@ static int mwifiex_uap_parse_tail_ies(struct mwifiex_private *priv, WLAN_OUI_TYPE_MICROSOFT_WPA, info->tail, info->tail_len); if (vendorhdr) { - memcpy(gen_ie->ie_buffer + ie_len, vendorhdr, - vendorhdr->len + sizeof(struct ieee_types_header)); - ie_len += vendorhdr->len + sizeof(struct ieee_types_header); + token_len = vendorhdr->len + sizeof(struct ieee_types_header); + if (ie_len + token_len > IEEE_MAX_IE_SIZE) { + err = -EINVAL; + goto out; + } + memcpy(gen_ie->ie_buffer + ie_len, vendorhdr, token_len); + ie_len += token_len; } - if (!ie_len) { - kfree(gen_ie); - return 0; - } + if (!ie_len) + goto out; gen_ie->ie_index = cpu_to_le16(gen_idx); gen_ie->mgmt_subtype_mask = cpu_to_le16(MGMT_MASK_BEACON | @@ -399,13 +412,15 @@ static int mwifiex_uap_parse_tail_ies(struct mwifiex_private *priv, if (mwifiex_update_uap_custom_ie(priv, gen_ie, &gen_idx, NULL, NULL, NULL, NULL)) { - kfree(gen_ie); - return -1; + err = -EINVAL; + goto out; } priv->gen_idx = gen_idx; + + out: kfree(gen_ie); - return 0; + return err; } /* This function parses different IEs-head & tail IEs, beacon IEs, -- cgit v1.2.3