ppp: deflate: never return len larger than output buffer

[ Upstream commit e2a4800e75780ccf4e6c2487f82b688ba736eb18 ] When we've run out of space in the output buffer to store more data, we will call zlib_deflate with a NULL output buffer until we've consumed remaining input. When this happens, olen contains the size the output buffer would have consumed iff we'd have had enough room. This can later cause skb_over_panic when ppp_generic skb_put()s the returned length. Reported-by: Iain Douglas <centos@1n6.org.uk> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ppp: deflate: never return len larger than output buffer
[ Upstream commit e2a4800e75780ccf4e6c2487f82b688ba736eb18 ] When we've run out of space in the output buffer to store more data, we will call zlib_deflate with a NULL output buffer until we've consumed remaining input. When this happens, olen contains the size the output buffer would have consumed iff we'd have had enough room. This can later cause skb_over_panic when ppp_generic skb_put()s the returned length. Reported-by: Iain Douglas <centos@1n6.org.uk> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Florian Westphal · Greg Kroah-Hartman
1 parent b974d00b77
Showing 1 changed file with 1 additions and 1 deletions Side-by-side Diff
drivers/net/ppp/ppp_deflate.c
@@ -246,7 +246,7 @@
 	/*
 	 * See if we managed to reduce the size of the packet.
 	 */
-	if (olen < isize) {
+	if (olen < isize && olen <= osize) {
 		state->stats.comp_bytes += olen;
 		state->stats.comp_packets++;
 	} else {
...	...	@@ -246,7 +246,7 @@
246	246	/*
247	247	* See if we managed to reduce the size of the packet.
248	248	*/
249		- if (olen < isize) {
	249	+ if (olen < isize && olen <= osize) {
250	250	state->stats.comp_bytes += olen;
251	251	state->stats.comp_packets++;
252	252	} else {