[ Upstream commit 13ec7f10b87f5fc04c4ccbd491c94c7980236a74 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/mwifiex/scan.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/net/wireless/mwifiex/scan.c b/drivers/net/wireless/mwifiex/scan.c index fb98f42cb5e7..6f789899c888 100644 --- a/drivers/net/wireless/mwifiex/scan.c +++ b/drivers/net/wireless/mwifiex/scan.c @@ -1219,6 +1219,8 @@ 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); @@ -1228,6 +1230,8 @@ 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,