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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 4843EC3A59E for ; Mon, 2 Sep 2019 11:06:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0BC27217D7 for ; Mon, 2 Sep 2019 11:06:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567422376; bh=vTuLNZWbArQhjA5Ei1L923sxshBXsB/l6eR0W0H2a70=; h=From:To:Cc:Subject:Date:List-ID:From; b=QwALoeqe/Fsles3OCh1VT/rq7Wl/mY6FdU0DfFyNTNkOSqxdHOgNUN31ko83SP+pi UmlHHtHbeaDGXhZGKx7Tpl07MFUjPRw5UzrHH10+MIBeUnBkPy2UPKjP3tMKbug3c0 XdaElFZ9h8ykoC+y3vZDbjY75VaSvPz9m/NO5QWQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731347AbfIBLGP (ORCPT ); Mon, 2 Sep 2019 07:06:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:39590 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727951AbfIBLGP (ORCPT ); Mon, 2 Sep 2019 07:06:15 -0400 Received: from localhost.localdomain (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AF65B2168B; Mon, 2 Sep 2019 11:06:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567422374; bh=vTuLNZWbArQhjA5Ei1L923sxshBXsB/l6eR0W0H2a70=; h=From:To:Cc:Subject:Date:From; b=B+62yvoudfnsvKVeTyvgp1D0xRdfIlnWUJivjQPY++omYfA4fllXkni7xL05eqvOv pzZAgUsnuQdi8DsarIj5fnhi/FWJcht4hjn7Ntc/CqhYrUoI1o717Q8N2oXOiFWm7s Ay026KeJkLSbcSWwU0nNBbt3qNDyLFcgBqd++xzs= From: Masami Hiramatsu To: Ingo Molnar Cc: Steven Rostedt , Masami Hiramatsu , "Naveen N . Rao" , Anil S Keshavamurthy , "David S . Miller" , linux-kernel@vger.kernel.org Subject: [PATCH -tip] kprobes: Prohibit probing on BUG() and WARN() address Date: Mon, 2 Sep 2019 20:06:09 +0900 Message-Id: <156742236963.18000.1855866569667433247.stgit@devnote2> X-Mailer: git-send-email 2.20.1 User-Agent: StGit/0.17.1-dirty 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 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 --- kernel/kprobes.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 452151e79535..771054401e35 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1514,7 +1514,8 @@ 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(p->addr)) { ret = -EINVAL; goto out; }