From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03381C433B4 for ; Tue, 6 Apr 2021 06:52:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C286C6136A for ; Tue, 6 Apr 2021 06:52:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244093AbhDFGwV (ORCPT ); Tue, 6 Apr 2021 02:52:21 -0400 Received: from out30-133.freemail.mail.aliyun.com ([115.124.30.133]:57012 "EHLO out30-133.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230296AbhDFGwU (ORCPT ); Tue, 6 Apr 2021 02:52:20 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04423;MF=jiapeng.chong@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0UUfZeID_1617691907; Received: from j63c13417.sqa.eu95.tbsite.net(mailfrom:jiapeng.chong@linux.alibaba.com fp:SMTPD_---0UUfZeID_1617691907) by smtp.aliyun-inc.com(127.0.0.1); Tue, 06 Apr 2021 14:52:11 +0800 From: Jiapeng Chong To: rostedt@goodmis.org Cc: mingo@redhat.com, linux-kernel@vger.kernel.org, Jiapeng Chong Subject: [PATCH] ftrace: Check if pages were allocated before calling free_pages() Date: Tue, 6 Apr 2021 14:51:45 +0800 Message-Id: <1617691905-8016-1-git-send-email-jiapeng.chong@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is possible that on error pg->size can be zero when getting its order,which would return a -1 value. It is dangerous to pass in an order of -1 to free_pages(). Check if order is greater than or equal to zero before calling free_pages(). Reported-by: Abaci Robot Signed-off-by: Jiapeng Chong --- kernel/trace/ftrace.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index b7e29db..74efc33 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6811,7 +6811,8 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) if (!pg->index) { *last_pg = pg->next; order = get_count_order(pg->size / ENTRIES_PER_PAGE); - free_pages((unsigned long)pg->records, order); + if (order >= 0) + free_pages((unsigned long)pg->records, order); ftrace_number_of_pages -= 1 << order; ftrace_number_of_groups--; kfree(pg); -- 1.8.3.1