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 <huangwen@venustech.com.cn>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
This commit is contained in:
Takashi Iwai 2019-05-29 14:52:19 +02:00 committed by Kalle Valo
parent 6aca09771d
commit 13ec7f10b8

View File

@ -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,