From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932527Ab1DMQIO (ORCPT ); Wed, 13 Apr 2011 12:08:14 -0400 Received: from kroah.org ([198.145.64.141]:54299 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757881Ab1DMPzX (ORCPT ); Wed, 13 Apr 2011 11:55:23 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Apr 13 08:51:45 2011 Message-Id: <20110413155145.542291931@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 13 Apr 2011 08:50:48 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Dan Rosenberg , "David S. Miller" Subject: [24/74] ROSE: prevent heap corruption with bad facilities In-Reply-To: <20110413155406.GA22568@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Dan Rosenberg commit be20250c13f88375345ad99950190685eda51eb8 upstream. When parsing the FAC_NATIONAL_DIGIS facilities field, it's possible for a remote host to provide more digipeaters than expected, resulting in heap corruption. Check against ROSE_MAX_DIGIS to prevent overflows, and abort facilities parsing on failure. Additionally, when parsing the FAC_CCITT_DEST_NSAP and FAC_CCITT_SRC_NSAP facilities fields, a remote host can provide a length of less than 10, resulting in an underflow in a memcpy size, causing a kernel panic due to massive heap corruption. A length of greater than 20 results in a stack overflow of the callsign array. Abort facilities parsing on these invalid length values. Signed-off-by: Dan Rosenberg Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/rose/rose_subr.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) --- a/net/rose/rose_subr.c +++ b/net/rose/rose_subr.c @@ -289,10 +289,15 @@ static int rose_parse_national(unsigned facilities->source_ndigis = 0; facilities->dest_ndigis = 0; for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) { - if (pt[6] & AX25_HBIT) + if (pt[6] & AX25_HBIT) { + if (facilities->dest_ndigis >= ROSE_MAX_DIGIS) + return -1; memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN); - else + } else { + if (facilities->source_ndigis >= ROSE_MAX_DIGIS) + return -1; memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN); + } } } p += l + 2; @@ -332,6 +337,11 @@ static int rose_parse_ccitt(unsigned cha case 0xC0: l = p[1]; + + /* Prevent overflows*/ + if (l < 10 || l > 20) + return -1; + if (*p == FAC_CCITT_DEST_NSAP) { memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN); memcpy(callsign, p + 12, l - 10); @@ -372,12 +382,16 @@ int rose_parse_facilities(unsigned char switch (*p) { case FAC_NATIONAL: /* National */ len = rose_parse_national(p + 1, facilities, facilities_len - 1); + if (len < 0) + return 0; facilities_len -= len + 1; p += len + 1; break; case FAC_CCITT: /* CCITT */ len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1); + if (len < 0) + return 0; facilities_len -= len + 1; p += len + 1; break;