From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 89FE311706 for ; Mon, 11 Sep 2023 15:03:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F2D7C433C8; Mon, 11 Sep 2023 15:03:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694444597; bh=BefLa8fgleMB0/aUIB7Pm3kl1kHxI8ieG7oxkhIojZM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QwxwUvdi/EtJpUNs7rELcX/oNUU1weeBc4iIE4d2YLy5FSvRpjr5bHH8tyrqz94a7 FzAQm4O/WTrumu3BzASI9LXcsgSY8JQAfcfhHSeOLiGtZorDrjTCm2F8m7vqbEOBjn GVHVjY9FQ+w2HtO3WDI54t0EP7g/DDi9Zvu9m6u0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Masami Hiramatsu (Google)" , "Steven Rostedt (Google)" , Sasha Levin Subject: [PATCH 6.1 047/600] kprobes: Prohibit probing on CFI preamble symbol Date: Mon, 11 Sep 2023 15:41:20 +0200 Message-ID: <20230911134634.985642721@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230911134633.619970489@linuxfoundation.org> References: <20230911134633.619970489@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masami Hiramatsu (Google) [ Upstream commit de02f2ac5d8cfb311f44f2bf144cc20002f1fbbd ] 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. Link: https://lore.kernel.org/all/168904024679.116016.18089228029322008512.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin --- kernel/kprobes.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 00e177de91ccd..3da9726232ff9 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; } -- 2.40.1