From patchwork Mon Jul 10 12:14:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 13306832 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 272EEEB64D9 for ; Mon, 10 Jul 2023 12:14:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231238AbjGJMOc (ORCPT ); Mon, 10 Jul 2023 08:14:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230492AbjGJMOb (ORCPT ); Mon, 10 Jul 2023 08:14:31 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B520D118; Mon, 10 Jul 2023 05:14:30 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4AD6260FD6; Mon, 10 Jul 2023 12:14:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1DD20C433C7; Mon, 10 Jul 2023 12:14:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1688991269; bh=/Q11alT8tbZRlfgyDDMM5QaswwfEKymoi7mANE+IolU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eBoK6rpnc6ooaLGvz/UPIrjCuWlziMTtlLYOn/o+xtxH7S6khirTDK2EfkX1Iw6TS /z+f6x1g8CfW5ke4WIyvljbM9SVmTXEWKp9VnVm54zNZG92Zl9FmWi1K2VNUs1Pj+T /NSMYsS3CWYPeMezLNMQ4DvwhBCyxzzxj4EhjnnrgxaEObXwE87lo4lK+vQ/uXZwJr dXHTvksru2ImAsvrhYVHeYrYsScbel2TVzCXFdXpPIAH742h3VRB4ttuJJlThQYia+ YlP8//zNN9PJO0cQiRcryLAuUB6HNbL/z0uOQ2Gfe6bE3h9QkQF3Nhx5/DabpCatqT +3+hx94BKLHUg== From: "Masami Hiramatsu (Google)" To: Peter Zijlstra Cc: Petr Pavlu , tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, samitolvanen@google.com, x86@kernel.org, linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, Masami Hiramatsu Subject: [RFC PATCH 1/2] kprobes: Prohibit probing on CFI preamble symbol Date: Mon, 10 Jul 2023 21:14:24 +0900 Message-Id: <168899126450.80889.16200438320430187434.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <168899125356.80889.17967397360941194229.stgit@devnote2> References: <168899125356.80889.17967397360941194229.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org From: Masami Hiramatsu (Google) Do not allow to probe on "__cfi_" started symbol, because it includes a typeid value in the code for CFI. Probing it will break the typeid checking. Signed-off-by: Masami Hiramatsu (Google) --- kernel/kprobes.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 00e177de91cc..ce2e460c1f79 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1545,6 +1545,20 @@ static int check_ftrace_location(struct kprobe *p) return 0; } +#ifdef CONFIG_CFI_CLANG +static bool is_cfi_preamble_symbol(unsigned long addr) +{ + char symbuf[KSYM_NAME_LEN]; + + if (lookup_symbol_name(addr, symbuf)) + return false; + + return str_has_prefix("__cfi_", symbuf); +} +#else +#define is_cfi_preamble_symbol(addr) (0) +#endif + static int check_kprobe_address_safe(struct kprobe *p, struct module **probed_mod) { @@ -1563,7 +1577,8 @@ static int check_kprobe_address_safe(struct kprobe *p, within_kprobe_blacklist((unsigned long) p->addr) || jump_label_text_reserved(p->addr, p->addr) || static_call_text_reserved(p->addr, p->addr) || - find_bug((unsigned long)p->addr)) { + find_bug((unsigned long)p->addr) || + is_cfi_preamble_symbol((unsigned long)p->addr)) { ret = -EINVAL; goto out; }