From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757284AbYKQH3c (ORCPT ); Mon, 17 Nov 2008 02:29:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751630AbYKQHVZ (ORCPT ); Mon, 17 Nov 2008 02:21:25 -0500 Received: from kroah.org ([198.145.64.141]:38464 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754603AbYKQHVO (ORCPT ); Mon, 17 Nov 2008 02:21:14 -0500 Date: Sun, 16 Nov 2008 23:15:43 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Alexey Dobriyan , Eric Dumazet , "David S. Miller" , Greg Kroah-Hartman Subject: [patch 23/46] net: fix /proc/net/snmp as memory corruptor Message-ID: <20081117071543.GX29522@kroah.com> References: <20081117070621.430169021@blue.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="net-fix-proc-net-snmp-as-memory-corruptor.patch" In-Reply-To: <20081117071333.GA29522@kroah.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Eric Dumazet commit b971e7ac834e9f4bda96d5a96ae9abccd01c1dd8 upstream. icmpmsg_put() can happily corrupt kernel memory, using a static table and forgetting to reset an array index in a loop. Remove the static array since its not safe without proper locking. Signed-off-by: Alexey Dobriyan Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/proc.c | 58 ++++++++++++++++++++++++++++---------------------------- 1 file changed, 30 insertions(+), 28 deletions(-) --- a/net/ipv4/proc.c +++ b/net/ipv4/proc.c @@ -237,43 +237,45 @@ static const struct snmp_mib snmp4_net_l SNMP_MIB_SENTINEL }; +static void icmpmsg_put_line(struct seq_file *seq, unsigned long *vals, + unsigned short *type, int count) +{ + int j; + + if (count) { + seq_printf(seq, "\nIcmpMsg:"); + for (j = 0; j < count; ++j) + seq_printf(seq, " %sType%u", + type[j] & 0x100 ? "Out" : "In", + type[j] & 0xff); + seq_printf(seq, "\nIcmpMsg:"); + for (j = 0; j < count; ++j) + seq_printf(seq, " %lu", vals[j]); + } +} + static void icmpmsg_put(struct seq_file *seq) { #define PERLINE 16 - int j, i, count; - static int out[PERLINE]; + int i, count; + unsigned short type[PERLINE]; + unsigned long vals[PERLINE], val; struct net *net = seq->private; count = 0; for (i = 0; i < ICMPMSG_MIB_MAX; i++) { - - if (snmp_fold_field((void **) net->mib.icmpmsg_statistics, i)) - out[count++] = i; - if (count < PERLINE) - continue; - - seq_printf(seq, "\nIcmpMsg:"); - for (j = 0; j < PERLINE; ++j) - seq_printf(seq, " %sType%u", i & 0x100 ? "Out" : "In", - i & 0xff); - seq_printf(seq, "\nIcmpMsg: "); - for (j = 0; j < PERLINE; ++j) - seq_printf(seq, " %lu", - snmp_fold_field((void **) net->mib.icmpmsg_statistics, - out[j])); - seq_putc(seq, '\n'); - } - if (count) { - seq_printf(seq, "\nIcmpMsg:"); - for (j = 0; j < count; ++j) - seq_printf(seq, " %sType%u", out[j] & 0x100 ? "Out" : - "In", out[j] & 0xff); - seq_printf(seq, "\nIcmpMsg:"); - for (j = 0; j < count; ++j) - seq_printf(seq, " %lu", snmp_fold_field((void **) - net->mib.icmpmsg_statistics, out[j])); + val = snmp_fold_field((void **) net->mib.icmpmsg_statistics, i); + if (val) { + type[count] = i; + vals[count++] = val; + } + if (count == PERLINE) { + icmpmsg_put_line(seq, vals, type, count); + count = 0; + } } + icmpmsg_put_line(seq, vals, type, count); #undef PERLINE } --