From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754189AbaDRMrB (ORCPT ); Fri, 18 Apr 2014 08:47:01 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:45782 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753374AbaDRMq5 (ORCPT ); Fri, 18 Apr 2014 08:46:57 -0400 X-IronPort-AV: E=Sophos;i="4.97,883,1389715200"; d="scan'208";a="29445287" From: Lai Jiangshan To: Tejun Heo , CC: Lai Jiangshan , Andrew Morton , Jean Delvare , Monam Agarwal , Jeff Layton , Andreas Gruenbacher , Stephen Hemminger Subject: [PATCH 2/8] idr: fix unexpected id-removal when idr_remove(unallocated_id) Date: Fri, 18 Apr 2014 20:49:49 +0800 Message-ID: <1397825404-12039-3-git-send-email-laijs@cn.fujitsu.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1397825404-12039-1-git-send-email-laijs@cn.fujitsu.com> References: <1397825404-12039-1-git-send-email-laijs@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.167.226.103] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If unallocated_id = (ANY * idr_max(idp->layers) + existed_id) is passed to idr_remove(). The existed_id will be removed unexpected. The following test shows this unexpected id-removal: static void test4(void) { int id; DEFINE_IDR(test_idr); printk(KERN_INFO "Start test4\n"); id = idr_alloc(&test_idr, (void *)1, 42, 43, GFP_KERNEL); BUG_ON(id != 42); idr_remove(&test_idr, 42 + IDR_SIZE); TEST_BUG_ON(idr_find(&test_idr, 42) != (void *)1); idr_destroy(&test_idr); printk(KERN_INFO "End of test4\n"); } It only happens when unallocated_id, it is caller's fault. It is not a bug. But it is better to add the proper check and complains instead of removing an existed_id silently. Signed-off-by: Lai Jiangshan --- lib/idr.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/lib/idr.c b/lib/idr.c index 4df6792..a28036d 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -562,6 +562,11 @@ void idr_remove(struct idr *idp, int id) if (id < 0) return; + if (id > idr_max(idp->layers)) { + idr_remove_warning(id); + return; + } + sub_remove(idp, (idp->layers - 1) * IDR_BITS, id); if (idp->top && idp->top->count == 1 && (idp->layers > 1) && idp->top->ary[0]) { -- 1.7.4.4