Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932224AbaFWNFr (ORCPT ); Mon, 23 Jun 2014 09:05:47 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:37310 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932198AbaFWNFo (ORCPT ); Mon, 23 Jun 2014 09:05:44 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Andy Lutomirski , Eric Paris , Linus Torvalds , Luis Henriques Subject: [PATCH 3.11 92/93] auditsc: audit_krule mask accesses need bounds checking Date: Mon, 23 Jun 2014 14:03:11 +0100 Message-Id: <1403528592-2163-93-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1403528592-2163-1-git-send-email-luis.henriques@canonical.com> References: <1403528592-2163-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.12 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Lutomirski commit a3c54931199565930d6d84f4c3456f6440aefd41 upstream. Fixes an easy DoS and possible information disclosure. This does nothing about the broken state of x32 auditing. eparis: If the admin has enabled auditd and has specifically loaded audit rules. This bug has been around since before git. Wow... Signed-off-by: Andy Lutomirski Signed-off-by: Eric Paris Signed-off-by: Linus Torvalds Signed-off-by: Luis Henriques --- kernel/auditsc.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 3b79a47ddb13..979c00bf24aa 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -733,6 +733,22 @@ static enum audit_state audit_filter_task(struct task_struct *tsk, char **key) return AUDIT_BUILD_CONTEXT; } +static int audit_in_mask(const struct audit_krule *rule, unsigned long val) +{ + int word, bit; + + if (val > 0xffffffff) + return false; + + word = AUDIT_WORD(val); + if (word >= AUDIT_BITMASK_SIZE) + return false; + + bit = AUDIT_BIT(val); + + return rule->mask[word] & bit; +} + /* At syscall entry and exit time, this filter is called if the * audit_state is not low enough that auditing cannot take place, but is * also not high enough that we already know we have to write an audit @@ -750,11 +766,8 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk, rcu_read_lock(); if (!list_empty(list)) { - int word = AUDIT_WORD(ctx->major); - int bit = AUDIT_BIT(ctx->major); - list_for_each_entry_rcu(e, list, list) { - if ((e->rule.mask[word] & bit) == bit && + if (audit_in_mask(&e->rule, ctx->major) && audit_filter_rules(tsk, &e->rule, ctx, NULL, &state, false)) { rcu_read_unlock(); @@ -774,20 +787,16 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk, static int audit_filter_inode_name(struct task_struct *tsk, struct audit_names *n, struct audit_context *ctx) { - int word, bit; int h = audit_hash_ino((u32)n->ino); struct list_head *list = &audit_inode_hash[h]; struct audit_entry *e; enum audit_state state; - word = AUDIT_WORD(ctx->major); - bit = AUDIT_BIT(ctx->major); - if (list_empty(list)) return 0; list_for_each_entry_rcu(e, list, list) { - if ((e->rule.mask[word] & bit) == bit && + if (audit_in_mask(&e->rule, ctx->major) && audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) { ctx->current_state = state; return 1; -- 1.9.1 -- 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/