Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754300AbbK3QdG (ORCPT ); Mon, 30 Nov 2015 11:33:06 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42360 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751926AbbK3QdC (ORCPT ); Mon, 30 Nov 2015 11:33:02 -0500 From: Marcelo Ricardo Leitner To: netdev@vger.kernel.org Cc: linux-sctp@vger.kernel.org, Vlad Yasevich , Neil Horman , daniel@iogearbox.net, linux-kernel@vger.kernel.org, davem@davemloft.net, syzkaller@googlegroups.com, dvyukov@google.com, kcc@google.com, glider@google.com, sasha.levin@oracle.com, edumazet@google.com Subject: [PATCH] sctp: use GFP_USER for user-controlled kmalloc Date: Mon, 30 Nov 2015 14:32:54 -0200 Message-Id: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1681 Lines: 44 Dmitry Vyukov reported that the user could trigger a kernel warning by using a large len value for getsockopt SCTP_GET_LOCAL_ADDRS, as that value directly affects the value used as a kmalloc() parameter. This patch thus switches the allocation flags from all user-controllable kmalloc size to GFP_USER to put some more restrictions on it and also disables the warn, as they are not necessary. Signed-off-by: Marcelo Ricardo Leitner Acked-by: Daniel Borkmann --- net/sctp/socket.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 897c01c029cab3d5805cc56b0964c70e06f4143a..676b3bb092e16848fd1c822e1c999af4a2ef198d 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -972,7 +972,7 @@ static int sctp_setsockopt_bindx(struct sock *sk, return -EFAULT; /* Alloc space for the address array in kernel memory. */ - kaddrs = kmalloc(addrs_size, GFP_KERNEL); + kaddrs = kmalloc(addrs_size, GFP_USER | __GFP_NOWARN); if (unlikely(!kaddrs)) return -ENOMEM; @@ -4928,7 +4928,7 @@ static int sctp_getsockopt_local_addrs(struct sock *sk, int len, to = optval + offsetof(struct sctp_getaddrs, addrs); space_left = len - offsetof(struct sctp_getaddrs, addrs); - addrs = kmalloc(space_left, GFP_KERNEL); + addrs = kmalloc(space_left, GFP_USER | __GFP_NOWARN); if (!addrs) return -ENOMEM; -- 2.5.0 -- 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/