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 <[EMAIL PROTECTED]>
---
As Sergey Vlasov pointed out, 
ppp_mppe-account-for-osize-too-small-errors-in.patch
may cause buffer overflows on certain data. Here is another patch that should
eliminate the "osize too small" errors. Instead of patching mppe_decompress
itself, I have patched ppp_decompress_frame so it would allocate the required
extra byte when using mppe compression.

I didn't have a chance to check this patch carefully yet, but it seem to be
working as expected. Any comments would be greatly appreciated.

--- linux-2.6.21.3/drivers/net/ppp_generic.c.orig       2007-06-20 
09:14:13.000000000
+1100
+++ linux-2.6.21.3/drivers/net/ppp_generic.c    2007-06-20 09:18:06.000000000 
+1100
@@ -1711,7 +1711,18 @@ ppp_decompress_frame(struct ppp *ppp, st
                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;
-
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