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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 0B29BC43461 for ; Thu, 15 Apr 2021 15:13:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8E4061184 for ; Thu, 15 Apr 2021 15:13:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235213AbhDOPNw (ORCPT ); Thu, 15 Apr 2021 11:13:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:48750 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234268AbhDOPC7 (ORCPT ); Thu, 15 Apr 2021 11:02:59 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C34FD61423; Thu, 15 Apr 2021 14:57:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1618498678; bh=pjVahfz3s20aR/AH0zANuMX4aIrcHcR3Y5XIu74Yg4A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nem/+lVyt0GSHInZUR1eaejsxenrKrOpGJvchTnKWIyTscQifnEBPwnyDYYKOBsVj McfHp3k8Qx+ZVtmldxPpNmEIK5FmblRf9mYBE6qbyyIr0oMRFq6HAr4Xfmds8d4Cea WVMS1o0Ni1NP2pUJYuT4W4YbRuEvouzRl8eHHYDM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Abaci Robot , "Steven Rostedt (VMware)" , Sasha Levin Subject: [PATCH 5.10 07/25] ftrace: Check if pages were allocated before calling free_pages() Date: Thu, 15 Apr 2021 16:48:01 +0200 Message-Id: <20210415144413.397686224@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210415144413.165663182@linuxfoundation.org> References: <20210415144413.165663182@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steven Rostedt (VMware) [ Upstream commit 59300b36f85f254260c81d9dd09195fa49eb0f98 ] 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(). Link: https://lore.kernel.org/lkml/20210330093916.432697c7@gandalf.local.home/ Reported-by: Abaci Robot Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin --- kernel/trace/ftrace.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 82041bbf8fc2..b1983c2aeb53 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3230,7 +3230,8 @@ ftrace_allocate_pages(unsigned long num_to_init) pg = start_pg; while (pg) { 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); start_pg = pg->next; kfree(pg); pg = start_pg; @@ -6452,7 +6453,8 @@ void ftrace_release_mod(struct module *mod) clear_mod_from_hashes(pg); 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); tmp_page = pg->next; kfree(pg); ftrace_number_of_pages -= 1 << order; @@ -6812,7 +6814,8 @@ 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); -- 2.30.2