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=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 40446FA372C for ; Fri, 8 Nov 2019 11:48:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0688D222CE for ; Fri, 8 Nov 2019 11:48:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573213708; bh=uvCdUrjrWSnYFMWKZGFTPKzZZAEZI014z2XOl7Z2dv4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HkSrUNw+Zk/wg3pfgudOmAsSlYgjC0btxX/hoL2pCFCavp7frw/HRbI+hUBg344de MqB6FcalT/7/gPF2EWwMkzenx84nozA9iRj1m2o5CsCghmycGkyEWrR8Lo3WwmfR5G yR45yG7QimVK++Bb3mOCcPxIo08msmY9DARf6dWY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391747AbfKHLs1 (ORCPT ); Fri, 8 Nov 2019 06:48:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:36766 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391643AbfKHLr6 (ORCPT ); Fri, 8 Nov 2019 06:47:58 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (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 E5BB6206A3; Fri, 8 Nov 2019 11:47:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573213677; bh=uvCdUrjrWSnYFMWKZGFTPKzZZAEZI014z2XOl7Z2dv4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CDypVvue3PmajijrA7JWgWR+3BmETcF7IjURqlYdTtxbKAFRXzxyhQE0FgeUfKNnK g9N1a/amnfXH1Ua11ENlrdZk2U9GOM758FXQ/krd+GweytzBy/fTZQB0NKxxG6aaX8 ksaydGO5l6o7N7cEDeoWWPzwrs5jq08xtVTYjHGk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Eric W. Biederman" , Thomas Gleixner , Sasha Levin Subject: [PATCH AUTOSEL 4.4 27/44] signal: Properly deliver SIGSEGV from x86 uprobes Date: Fri, 8 Nov 2019 06:47:03 -0500 Message-Id: <20191108114721.15944-27-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191108114721.15944-1-sashal@kernel.org> References: <20191108114721.15944-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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