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,URIBL_BLOCKED,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 53C5DC432C0 for ; Fri, 22 Nov 2019 10:32:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 22EF320726 for ; Fri, 22 Nov 2019 10:32:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574418751; bh=B6jxOLBd/9zLkLYcoyos7p5ppKFoQ1iXiFOWPgY7BhY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tFl/LHZBz17ScFllBJHZVcxzL4/KFkutighVfloqBrHaZ+s4D3QZXLONQAVYoa9PJ xIF0oNqZXez//XzgPcA5FHPXl5dZjgvw/2+E+rYPe2W5bPPDUR83xRW/XL0riJiqXy LTOLVAWgXwnnEM6MNmdDUwHK9/fjnT99GUGWLJEM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727693AbfKVKca (ORCPT ); Fri, 22 Nov 2019 05:32:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:53836 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727667AbfKVKcZ (ORCPT ); Fri, 22 Nov 2019 05:32:25 -0500 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 71FB82082F; Fri, 22 Nov 2019 10:32:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574418745; bh=B6jxOLBd/9zLkLYcoyos7p5ppKFoQ1iXiFOWPgY7BhY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=08mn1FOG2F8rygIaglGgsQ2cpNuNgv/E+2w7FndyyULxIa/kqSHrR5CIPsFma2z7V oq9867p6bQBiXOXBvq5C3flaq/ick2VhQXwSUtB/BgWfssO+iLZYUjLHdaYrhL5I2o qwK5vJJX3Jzql9iICa3hwtuZSwJRBh6Gseplmo8s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , "Eric W. Biederman" , Sasha Levin Subject: [PATCH 4.4 038/159] signal: Properly deliver SIGSEGV from x86 uprobes Date: Fri, 22 Nov 2019 11:27:09 +0100 Message-Id: <20191122100734.245850658@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191122100704.194776704@linuxfoundation.org> References: <20191122100704.194776704@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: Eric W. Biederman [ Upstream commit 4a63c1ffd384ebdce40aac9c997dab68379137be ] For userspace to tell the difference between an random signal and an exception, the exception must include siginfo information. Using SEND_SIG_FORCED for SIGSEGV is thus wrong, and it will result in userspace seeing si_code == SI_USER (like a random signal) instead of si_code == SI_KERNEL or a more specific si_code as all exceptions deliver. Therefore replace force_sig_info(SIGSEGV, SEND_SIG_FORCE, current) with force_sig(SIG_SEGV, current) which gets this right and is shorter and easier to type. Fixes: 791eca10107f ("uretprobes/x86: Hijack return address") Reviewed-by: Thomas Gleixner Signed-off-by: "Eric W. Biederman" Signed-off-by: Sasha Levin --- arch/x86/kernel/uprobes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 178d63cac321b..60b12c14cf6fb 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -983,7 +983,7 @@ arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs pr_err("uprobe: return address clobbered: pid=%d, %%sp=%#lx, " "%%ip=%#lx\n", current->pid, regs->sp, regs->ip); - force_sig_info(SIGSEGV, SEND_SIG_FORCED, current); + force_sig(SIGSEGV, current); } return -1; -- 2.20.1