staging: rtl8712: memory corruption in wpa_set_encryption()

->KeyMaterial is declared as a 16 byte array, but we only ever allocate
either 5 or 13 bytes of it.  The problem is that we memset() all 16
bytes to zero so we're memsetting past the end of the allocated memory.

I fixed this in slightly lazy way, by just allocating 16 bytes.  This
works but there is a lot more cleanup you could do to this code if you
wanted.  Which is why this code is in staging.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/rtl8712/rtl871x_ioctl_linux.c b/drivers/staging/rtl8712/rtl871x_ioctl_linux.c
index edfc680..db2e31b 100644 (file)
--- a/drivers/staging/rtl8712/rtl871x_ioctl_linux.c
+++ b/drivers/staging/rtl8712/rtl871x_ioctl_linux.c
@@ -398,12 +398,9 @@ static int wpa_set_encryption(struct net_device *dev, struct ieee_param *param,
                        wep_key_idx = 0;
                if (wep_key_len > 0) {
                        wep_key_len = wep_key_len <= 5 ? 5 : 13;
-                       pwep = kmalloc((u32)(wep_key_len +
-                               FIELD_OFFSET(struct NDIS_802_11_WEP,
-                               KeyMaterial)), GFP_ATOMIC);
+                       pwep = kzalloc(sizeof(*pwep), GFP_ATOMIC);
                        if (pwep == NULL)
                                return -ENOMEM;
-                       memset(pwep, 0, sizeof(struct NDIS_802_11_WEP));
                        pwep->KeyLength = wep_key_len;
                        pwep->Length = wep_key_len +
                                 FIELD_OFFSET(struct NDIS_802_11_WEP,