From patchwork Tue Jul 11 01:50:47 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: 13307956 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 BFBFAEB64DC for ; Tue, 11 Jul 2023 01:51:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230121AbjGKBv0 (ORCPT ); Mon, 10 Jul 2023 21:51:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229532AbjGKBvV (ORCPT ); Mon, 10 Jul 2023 21:51:21 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7721CB6; Mon, 10 Jul 2023 18:50:53 -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 116CC612C3; Tue, 11 Jul 2023 01:50:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A1C2BC433C8; Tue, 11 Jul 2023 01:50:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1689040252; bh=G53cisJ1oPIw1E6Ka9hA5wzdkbxHiWemrgTO3t6vUgU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YSU9s+PAzFuCiDGKH9vHy8rem2/DY9PbpK/6bUGql+kKCiDqfW+Qbvl4+QVA0vuDt zh3kL+cUW8kav3KW/YbyKIx6/2cvcDlBkB014nG4SAoDUgM99tZDWezx0nRwhQjCUq sQsLQtANnT7abWt+M/+6xH4QuR+7FS7qb0GzSjZCgwujOCgui2s82sWeZ6qh2g7cvP SUZlHejcuVrPISlkg6UI2F4ZdO7eumJkNoKsoyafTY3fowcSAAbKTfFGnJzEV2NXIs kBNoTqWZvHYh6mC3x/uIuD9XwIiAs1XLa1t8iSYUnR5Rjd2tJOpZYgbdtDxmbReevl IDVTvz1xLJXEA== 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: [PATCH v2 1/2] kprobes: Prohibit probing on CFI preamble symbol Date: Tue, 11 Jul 2023 10:50:47 +0900 Message-Id: <168904024679.116016.18089228029322008512.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <168904023542.116016.10540228903086100726.stgit@devnote2> References: <168904023542.116016.10540228903086100726.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_" or "__pfx_" started symbol, because those are used for CFI and not executed. Probing it will break the CFI. Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Steven Rostedt (Google) --- Changes in v2: - Check "__pfx_" prefix functions too. - Make the check unconditional. --- kernel/kprobes.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 00e177de91cc..3da9726232ff 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1545,6 +1545,17 @@ static int check_ftrace_location(struct kprobe *p) return 0; } +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) || + str_has_prefix("__pfx_", symbuf); +} + static int check_kprobe_address_safe(struct kprobe *p, struct module **probed_mod) { @@ -1563,7 +1574,8 @@ 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; }