From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DADD7C10F14 for ; Thu, 3 Oct 2019 15:58:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9B27B222C9 for ; Thu, 3 Oct 2019 15:58:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570118323; bh=vjBaosXqtd9ltgOm7s+SR9vWpf2jQAJtR0eeELBX1YY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=pWPD6Vh9xwilRXQgz0pdVcA2pYX8aKnb+Rx8K/H2PEepqEiVDJlLzf61uodjr43tG nbJr0ZiECWhe3SUez3aMp4z4ZAjdI5WSl6KS+zg8j7eDlcebkt134YWEPv7NKmr7vp fheVxEYOug3s4p9JpJmgDnf3hIpCkJnwm5tNJmpk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731278AbfJCP6m (ORCPT ); Thu, 3 Oct 2019 11:58:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:41482 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730091AbfJCP6k (ORCPT ); Thu, 3 Oct 2019 11:58:40 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4A31421848; Thu, 3 Oct 2019 15:58:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570118319; bh=vjBaosXqtd9ltgOm7s+SR9vWpf2jQAJtR0eeELBX1YY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=llxWVXiOvb/pFN8LN8MhAMFSBIOIVVr7CeJ1Tn00fs898pJtE4RlqEk5kopQH8UlD ojTA01GCcgBL9hML2htwZMnRvMfjh9jiAP5yVvkjgwNlQjRl8rZRcFSmuNmeHOJW74 Pbqcl48PUfARV+Xruw4DRDWzzUlUs8g5YVRELQLg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Masami Hiramatsu , "Steven Rostedt (VMware)" , "Naveen N. Rao" , Anil S Keshavamurthy , "David S . Miller" , Linus Torvalds , "Naveen N . Rao" , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Sasha Levin Subject: [PATCH 4.4 68/99] kprobes: Prohibit probing on BUG() and WARN() address Date: Thu, 3 Oct 2019 17:53:31 +0200 Message-Id: <20191003154329.926825063@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154252.297991283@linuxfoundation.org> References: <20191003154252.297991283@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Masami Hiramatsu [ Upstream commit e336b4027775cb458dc713745e526fa1a1996b2a ] Since BUG() and WARN() may use a trap (e.g. UD2 on x86) to get the address where the BUG() has occurred, kprobes can not do single-step out-of-line that instruction. So prohibit probing on such address. Without this fix, if someone put a kprobe on WARN(), the kernel will crash with invalid opcode error instead of outputing warning message, because kernel can not find correct bug address. Signed-off-by: Masami Hiramatsu Acked-by: Steven Rostedt (VMware) Acked-by: Naveen N. Rao Cc: Anil S Keshavamurthy Cc: David S . Miller Cc: Linus Torvalds Cc: Naveen N . Rao Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/156750890133.19112.3393666300746167111.stgit@devnote2 Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- include/linux/bug.h | 5 +++++ kernel/kprobes.c | 3 ++- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/include/linux/bug.h b/include/linux/bug.h index 7f4818673c41f..581a53dfbd310 100644 --- a/include/linux/bug.h +++ b/include/linux/bug.h @@ -102,6 +102,11 @@ int is_valid_bugaddr(unsigned long addr); #else /* !CONFIG_GENERIC_BUG */ +static inline void *find_bug(unsigned long bugaddr) +{ + return NULL; +} + static inline enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs) { diff --git a/kernel/kprobes.c b/kernel/kprobes.c index a53998cba804c..fdde50d39a46d 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1454,7 +1454,8 @@ static int check_kprobe_address_safe(struct kprobe *p, /* Ensure it is not in reserved area nor out of text */ if (!kernel_text_address((unsigned long) p->addr) || within_kprobe_blacklist((unsigned long) p->addr) || - jump_label_text_reserved(p->addr, p->addr)) { + jump_label_text_reserved(p->addr, p->addr) || + find_bug((unsigned long)p->addr)) { ret = -EINVAL; goto out; } -- 2.20.1