From patchwork Mon Dec 6 14:56:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 522182 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4000C433FE for ; Mon, 6 Dec 2021 15:14:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358271AbhLFPRo (ORCPT ); Mon, 6 Dec 2021 10:17:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54290 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347453AbhLFPOp (ORCPT ); Mon, 6 Dec 2021 10:14:45 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5338EC0698D5; Mon, 6 Dec 2021 07:07:38 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 1F179B810E7; Mon, 6 Dec 2021 15:07:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6690EC341C1; Mon, 6 Dec 2021 15:07:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1638803256; bh=qHA3pse0aJpPJ8bg2NKqEmnqjVvguuq1LWSl+GxzR1A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vkidqR15FQDPdE215CnL6HK8TR4eN7EDjqOZaM0fmbPjDOPdVakSkJ5IYMa+DcQeh FvmHZLfowYNMef+bLkGyPZTjwbLTYGEWiP3qoVoZQ6vB/Aqz6ISQXAPSfQ87CDzVXC Lr3Wr0GrHTyzUSWKlzGqzMRVQ9ejUCLICxIoR9W4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, zhangyue , Masami Hiramatsu , "Steven Rostedt (VMware)" Subject: [PATCH 4.14 084/106] kprobes: Limit max data_size of the kretprobe instances Date: Mon, 6 Dec 2021 15:56:32 +0100 Message-Id: <20211206145558.419381527@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211206145555.386095297@linuxfoundation.org> References: <20211206145555.386095297@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Masami Hiramatsu commit 6bbfa44116689469267f1a6e3d233b52114139d2 upstream. The 'kprobe::data_size' is unsigned, thus it can not be negative. But if user sets it enough big number (e.g. (size_t)-8), the result of 'data_size + sizeof(struct kretprobe_instance)' becomes smaller than sizeof(struct kretprobe_instance) or zero. In result, the kretprobe_instance are allocated without enough memory, and kretprobe accesses outside of allocated memory. To avoid this issue, introduce a max limitation of the kretprobe::data_size. 4KB per instance should be OK. Link: https://lkml.kernel.org/r/163836995040.432120.10322772773821182925.stgit@devnote2 Cc: stable@vger.kernel.org Fixes: f47cd9b553aa ("kprobes: kretprobe user entry-handler") Reported-by: zhangyue Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- include/linux/kprobes.h | 2 ++ kernel/kprobes.c | 3 +++ 2 files changed, 5 insertions(+) --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -193,6 +193,8 @@ struct kretprobe { raw_spinlock_t lock; }; +#define KRETPROBE_MAX_DATA_SIZE 4096 + struct kretprobe_instance { struct hlist_node hlist; struct kretprobe *rp; --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2004,6 +2004,9 @@ int register_kretprobe(struct kretprobe } } + if (rp->data_size > KRETPROBE_MAX_DATA_SIZE) + return -E2BIG; + rp->kp.pre_handler = pre_handler_kretprobe; rp->kp.post_handler = NULL; rp->kp.fault_handler = NULL;