Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965297AbbBQLt4 (ORCPT ); Tue, 17 Feb 2015 06:49:56 -0500 Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:39884 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756954AbbBQLfO (ORCPT ); Tue, 17 Feb 2015 06:35:14 -0500 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Florian Westphal , "David S. Miller" , Jiri Slaby Subject: [PATCH 3.12 090/122] ppp: deflate: never return len larger than output buffer Date: Tue, 17 Feb 2015 12:34:37 +0100 Message-Id: <030892ea1af3f4ff26a9474690e75f211b9b592a.1424099974.git.jslaby@suse.cz> X-Mailer: git-send-email 2.2.2 In-Reply-To: <09e6fe32192a77f6e2e60cc0f4103e630c7ecf20.1424099973.git.jslaby@suse.cz> References: <09e6fe32192a77f6e2e60cc0f4103e630c7ecf20.1424099973.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1579 Lines: 47 From: Florian Westphal 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ 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 Signed-off-by: Florian Westphal Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- drivers/net/ppp/ppp_deflate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ppp/ppp_deflate.c b/drivers/net/ppp/ppp_deflate.c index 602c625d95d5..b5edc7f96a39 100644 --- a/drivers/net/ppp/ppp_deflate.c +++ b/drivers/net/ppp/ppp_deflate.c @@ -246,7 +246,7 @@ static int z_compress(void *arg, unsigned char *rptr, unsigned char *obuf, /* * 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 { -- 2.2.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/