From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935386AbcLMTxa (ORCPT ); Tue, 13 Dec 2016 14:53:30 -0500 Received: from mx2.suse.de ([195.135.220.15]:54243 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934859AbcLMTxX (ORCPT ); Tue, 13 Dec 2016 14:53:23 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Eric Dumazet , "David S . Miller" , Jiri Slaby Subject: [PATCH 3.12 34/38] net: avoid signed overflows for SO_{SND|RCV}BUFFORCE Date: Tue, 13 Dec 2016 20:53:00 +0100 Message-Id: <40c753f1714416931dc093b960aa3fcac4a545c5.1481658746.git.jslaby@suse.cz> X-Mailer: git-send-email 2.11.0 In-Reply-To: <15034b96ec06ee859b67c6cd4e3be569a4ef286b.1481658746.git.jslaby@suse.cz> References: <15034b96ec06ee859b67c6cd4e3be569a4ef286b.1481658746.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 From: Eric Dumazet 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ Upstream commit b98b0bc8c431e3ceb4b26b0dfc8db509518fb290 ] CAP_NET_ADMIN users should not be allowed to set negative sk_sndbuf or sk_rcvbuf values, as it can lead to various memory corruptions, crashes, OOM... Note that before commit 82981930125a ("net: cleanups in sock_setsockopt()"), the bug was even more serious, since SO_SNDBUF and SO_RCVBUF were vulnerable. This needs to be backported to all known linux kernels. Again, many thanks to syzkaller team for discovering this gem. Signed-off-by: Eric Dumazet Reported-by: Andrey Konovalov Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- net/core/sock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/core/sock.c b/net/core/sock.c index 73c6093e136a..7fa427ed41bc 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -728,7 +728,7 @@ int sock_setsockopt(struct socket *sock, int level, int optname, val = min_t(u32, val, sysctl_wmem_max); set_sndbuf: sk->sk_userlocks |= SOCK_SNDBUF_LOCK; - sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF); + sk->sk_sndbuf = max_t(int, val * 2, SOCK_MIN_SNDBUF); /* Wake up sending tasks if we upped the value. */ sk->sk_write_space(sk); break; @@ -764,7 +764,7 @@ set_rcvbuf: * returning the value we actually used in getsockopt * is the most desirable behavior. */ - sk->sk_rcvbuf = max_t(u32, val * 2, SOCK_MIN_RCVBUF); + sk->sk_rcvbuf = max_t(int, val * 2, SOCK_MIN_RCVBUF); break; case SO_RCVBUFFORCE: -- 2.11.0