Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932421Ab1DZV2W (ORCPT ); Tue, 26 Apr 2011 17:28:22 -0400 Received: from mga11.intel.com ([192.55.52.93]:60444 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932326Ab1DZVOd (ORCPT ); Tue, 26 Apr 2011 17:14:33 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.64,270,1301900400"; d="scan'208";a="684327301" From: Andi Kleen References: <20110426212.641772347@firstfloor.org> In-Reply-To: <20110426212.641772347@firstfloor.org> To: drosenberg@vsecurity.com, davem@davemloft.net, ak@linux.intel.com, jmm@debian.org, gregkh@suse.de, linux-kernel@vger.kernel.org, stable@kernel.org, tim.bird@am.sony.com Subject: [PATCH] [49/106] irda: prevent integer underflow in IRLMP_ENUMDEVICES Message-Id: <20110426211329.4F22C3E1886@tassilo.jf.intel.com> Date: Tue, 26 Apr 2011 14:13:29 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2266 Lines: 65 2.6.35-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Dan Rosenberg commit fdac1e0697356ac212259f2147aa60c72e334861 upstream. If the user-provided len is less than the expected offset, the IRLMP_ENUMDEVICES getsockopt will do a copy_to_user() with a very large size value. While this isn't be a security issue on x86 because it will get caught by the access_ok() check, it may leak large amounts of kernel heap on other architectures. In any event, this patch fixes it. Signed-off-by: Dan Rosenberg Signed-off-by: David S. Miller Signed-off-by: Andi Kleen Cc: Moritz Muehlenhoff Signed-off-by: Greg Kroah-Hartman --- net/irda/af_irda.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) Index: linux-2.6.35.y/net/irda/af_irda.c =================================================================== --- linux-2.6.35.y.orig/net/irda/af_irda.c +++ linux-2.6.35.y/net/irda/af_irda.c @@ -2278,6 +2278,14 @@ static int __irda_getsockopt(struct sock switch (optname) { case IRLMP_ENUMDEVICES: + + /* Offset to first device entry */ + offset = sizeof(struct irda_device_list) - + sizeof(struct irda_device_info); + + if (len < offset) + return -EINVAL; + /* Ask lmp for the current discovery log */ discoveries = irlmp_get_discoveries(&list.len, self->mask.word, self->nslots); @@ -2287,15 +2295,9 @@ static int __irda_getsockopt(struct sock err = 0; /* Write total list length back to client */ - if (copy_to_user(optval, &list, - sizeof(struct irda_device_list) - - sizeof(struct irda_device_info))) + if (copy_to_user(optval, &list, offset)) err = -EFAULT; - /* Offset to first device entry */ - offset = sizeof(struct irda_device_list) - - sizeof(struct irda_device_info); - /* Copy the list itself - watch for overflow */ if(list.len > 2048) { -- 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/