[PPP]: Fix osize too small errors when decoding mppe.

The mppe_decompress() function required a buffer that is 1 byte too
small when receiving a message of mru size. This fixes buffer
allocation to prevent this from occurring.

Signed-off-by: Konstantin Sharlaimov <konstantin.sharlaimov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 1 deletions

diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c
index 541168713f1f..3ef0092dc09c 100644
--- a/drivers/net/ppp_generic.c
+++ b/drivers/net/ppp_generic.c
@@ -1708,7 +1708,18 @@ ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
                 goto err;
 
         if (proto == PPP_COMP) {
-                ns = dev_alloc_skb(ppp->mru + PPP_HDRLEN);
+                int obuff_size;
+
+                switch(ppp->rcomp->compress_proto) {
+                case CI_MPPE:
+                        obuff_size = ppp->mru + PPP_HDRLEN + 1;
+                        break;
+                default:
+                        obuff_size = ppp->mru + PPP_HDRLEN;
+                        break;
+                }
+
+                ns = dev_alloc_skb(obuff_size);
                 if (ns == 0) {
                         printk(KERN_ERR "ppp_decompress_frame: no memory\n");
                         goto err;