From nobody Sat Feb 7 22:00:04 2026 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 CC7B0C32774 for ; Tue, 23 Aug 2022 10:02:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243967AbiHWKCx (ORCPT ); Tue, 23 Aug 2022 06:02:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352462AbiHWJ47 (ORCPT ); Tue, 23 Aug 2022 05:56:59 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 46053A1A64; Tue, 23 Aug 2022 01:47:40 -0700 (PDT) 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 132AFB81C28; Tue, 23 Aug 2022 08:47:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61054C433D6; Tue, 23 Aug 2022 08:47:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661244456; bh=5W9S8KSf9oP4xZJYWjinORLtbpUFU6U4C0Ne61cmBMQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L4ffls+5gTUPk2XaC0IX1idj3OjcHTA7lPhWqdf9fo28hX6y3xUDBChMQEduzSUhm skAGxn/4tMoxoiD+ixz/0DUnlAtZOXgEKqD0mxJffn5z9DSVyeLvJxFHhzItggIhT9 9gHkTpnq4Tyw/NwGpR2B45zJgBY4zO2IXjSnbbZM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chen Zhongjin , Ingo Molnar , "Masami Hiramatsu (Google)" , Sasha Levin Subject: [PATCH 4.14 140/229] kprobes: Forbid probing on trampoline and BPF code areas Date: Tue, 23 Aug 2022 10:25:01 +0200 Message-Id: <20220823080058.685732796@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080053.202747790@linuxfoundation.org> References: <20220823080053.202747790@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Chen Zhongjin [ Upstream commit 28f6c37a2910f565b4f5960df52b2eccae28c891 ] kernel_text_address() treats ftrace_trampoline, kprobe_insn_slot and bpf_text_address as valid kprobe addresses - which is not ideal. These text areas are removable and changeable without any notification to kprobes, and probing on them can trigger unexpected behavior: https://lkml.org/lkml/2022/7/26/1148 Considering that jump_label and static_call text are already forbiden to probe, kernel_text_address() should be replaced with core_kernel_text() and is_module_text_address() to check other text areas which are unsafe to kprobe. [ mingo: Rewrote the changelog. ] Fixes: 5b485629ba0d ("kprobes, extable: Identify kprobes trampolines as ker= nel text area") Fixes: 74451e66d516 ("bpf: make jited programs visible in traces") Signed-off-by: Chen Zhongjin Signed-off-by: Ingo Molnar Acked-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/r/20220801033719.228248-1-chenzhongjin@huawei= .com Signed-off-by: Sasha Levin --- kernel/kprobes.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 4f918dd28fb7..b8e14aa6d496 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1551,7 +1551,8 @@ static int check_kprobe_address_safe(struct kprobe *p, preempt_disable(); =20 /* Ensure it is not in reserved area nor out of text */ - if (!kernel_text_address((unsigned long) p->addr) || + if (!(core_kernel_text((unsigned long) p->addr) || + is_module_text_address((unsigned long) p->addr)) || within_kprobe_blacklist((unsigned long) p->addr) || jump_label_text_reserved(p->addr, p->addr) || find_bug((unsigned long)p->addr)) { --=20 2.35.1