From: Takashi Iwai Date: Wed, 29 May 2019 12:52:19 +0000 (+0200) Subject: mwifiex: Fix possible buffer overflows at parsing bss descriptor X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=13ec7f10b87f5fc04c4ccbd491c94c7980236a74;p=linux.git 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 --- diff --git a/drivers/net/wireless/marvell/mwifiex/scan.c b/drivers/net/wireless/marvell/mwifiex/scan.c index 935778ec9a1b4..64ab6fe78c0da 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,