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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 D1994C433DF for ; Wed, 10 Jun 2020 14:53:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A988B2078C for ; Wed, 10 Jun 2020 14:53:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SW9VZ65f" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729972AbgFJOx5 (ORCPT ); Wed, 10 Jun 2020 10:53:57 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:42683 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729945AbgFJOxv (ORCPT ); Wed, 10 Jun 2020 10:53:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591800829; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IbTlbvpZrjIt//+klHw+rfy1TKM7Gl7DCLWB4vzgCck=; b=SW9VZ65fSxcqT+4V6nlzi257B2k8CtFJP5wH2Wgl27nwUMzZ/dzte9Vt3dqSU8SSp6Owem chNYU+tLPujGbbjb+LkgO279I8P1PquBVsfW7nijvz1vhCqcsSgUUBIvPN9qJGeLPmIerJ d1jPQ0jMu3Xq2Y1+QvVKEcNjF6F/ZI4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-290-5TsqfYi9M4uGVu0V354nDg-1; Wed, 10 Jun 2020 10:53:43 -0400 X-MC-Unique: 5TsqfYi9M4uGVu0V354nDg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4264118A4175; Wed, 10 Jun 2020 14:53:10 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.40.193.72]) by smtp.corp.redhat.com (Postfix) with SMTP id AD26E5C1BD; Wed, 10 Jun 2020 14:53:07 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 10 Jun 2020 16:53:09 +0200 (CEST) Date: Wed, 10 Jun 2020 16:53:06 +0200 From: Oleg Nesterov To: Greg Kroah-Hartman Cc: Naresh Kamboju , open list , linux- stable , Linus Torvalds , Srikar Dronamraju , Christian Borntraeger , Sven Schnelle , Steven Rostedt , lkft-triage@lists.linaro.org Subject: Re: [PATCH 4.19 24/25] uprobes: ensure that uprobe->offset and ->ref_ctr_offset are properly aligned Message-ID: <20200610145305.GA3254@redhat.com> References: <20200609174048.576094775@linuxfoundation.org> <20200609174051.488794266@linuxfoundation.org> <20200609190321.GA1046130@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200609190321.GA1046130@kroah.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/09, Greg Kroah-Hartman wrote: > > On Wed, Jun 10, 2020 at 12:25:56AM +0530, Naresh Kamboju wrote: > > > @@ -911,6 +907,15 @@ static int __uprobe_register(struct inod > > > if (offset > i_size_read(inode)) > > > return -EINVAL; > > > > > > + /* > > > + * This ensures that copy_from_page(), copy_to_page() and > > > + * __update_ref_ctr() can't cross page boundary. > > > + */ > > > + if (!IS_ALIGNED(offset, UPROBE_SWBP_INSN_SIZE)) > > > + return -EINVAL; > > > + if (!IS_ALIGNED(ref_ctr_offset, sizeof(short))) > > > > stable-rc 4.19 build failure for x86_64, i386 and arm. > > make -sk KBUILD_BUILD_USER=TuxBuild -C/linux -j16 ARCH=x86 HOSTCC=gcc > > CC="sccache gcc" O=build > > > > 75 # > > 76 In file included from ../kernel/events/uprobes.c:25: > > 77 ../kernel/events/uprobes.c: In function ‘__uprobe_register’: > > 78 ../kernel/events/uprobes.c:916:18: error: ‘ref_ctr_offset’ > > undeclared (first use in this function); did you mean > > ‘per_cpu_offset’? > > 79 916 | if (!IS_ALIGNED(ref_ctr_offset, sizeof(short))) > > 80 | ^~~~~~~~~~~~~~ > > 81 ../include/linux/kernel.h:62:30: note: in definition of macro ‘IS_ALIGNED’ > > 82 62 | #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) > > 83 | ^ > > 84 ../kernel/events/uprobes.c:916:18: note: each undeclared identifier > > is reported only once for each function it appears in > > 85 916 | if (!IS_ALIGNED(ref_ctr_offset, sizeof(short))) > > 86 | ^~~~~~~~~~~~~~ > > 87 ../include/linux/kernel.h:62:30: note: in definition of macro ‘IS_ALIGNED’ > > 88 62 | #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) > > 89 | ^ > > 90 make[3]: *** [../scripts/Makefile.build:304: kernel/events/uprobes.o] Error 1 > > > > -- > > Linaro LKFT > > https://lkft.linaro.org > > Good catch, my builders just caught it too :( > > 4.19, 4.14, 4.9, and 4.4 are all broken, I have a fix will test it and > push out -rc2 for all of those with it in a bit, thanks. Yes, SDT markers were added by 1cc33161a83d20b5462b1e93f95d3ce6388079ee in v4.20. See the patch for v4.4 below. It changes uprobe_register(), not __uprobe_register() to check IS_ALIGNED(offset, UPROBE_SWBP_INSN_SIZE) only. Greg, please let me know if you want me to send the patches for 4.9/4.14/4.19. Oleg. --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -601,10 +601,6 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file, if (ret) goto out; - /* uprobe_write_opcode() assumes we don't cross page boundary */ - BUG_ON((uprobe->offset & ~PAGE_MASK) + - UPROBE_SWBP_INSN_SIZE > PAGE_SIZE); - smp_wmb(); /* pairs with rmb() in find_active_uprobe() */ set_bit(UPROBE_COPY_INSN, &uprobe->flags); @@ -883,6 +879,13 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer * if (offset > i_size_read(inode)) return -EINVAL; + /* + * This ensures that copy_from_page() an copy_to_page() + * can't cross page boundary. + */ + if (!IS_ALIGNED(offset, UPROBE_SWBP_INSN_SIZE)) + return -EINVAL; + retry: uprobe = alloc_uprobe(inode, offset); if (!uprobe) @@ -1691,6 +1694,9 @@ static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr) uprobe_opcode_t opcode; int result; + if (WARN_ON_ONCE(!IS_ALIGNED(vaddr, UPROBE_SWBP_INSN_SIZE))) + return -EINVAL; + pagefault_disable(); result = __copy_from_user_inatomic(&opcode, (void __user*)vaddr, sizeof(opcode));