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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 EDA4BC433DF for ; Tue, 9 Jun 2020 19:03:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB7B7206C3 for ; Tue, 9 Jun 2020 19:03:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591729408; bh=Vfyj+NMf8T/7CXC12HCXGIpKKfBA7HOZ+MDv198zK9s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=hyNhclzA/k1t3A+6AVaX75wG4vVRWTVljBzUk0H3NQq5oxJbg09MAGJKzcGxZbxN7 YW4xBh00Dz27gzcJCjKw8Um5JQJRDeznziFUnti6g4pEHedHVKi5lW5p9s4LqtoVCv /xz3hEtmlSuJ7B8OCt2XT2l6kwk57LE3E4q+4+X4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730360AbgFITD0 (ORCPT ); Tue, 9 Jun 2020 15:03:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:40298 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729806AbgFITDZ (ORCPT ); Tue, 9 Jun 2020 15:03:25 -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 DEC642068D; Tue, 9 Jun 2020 19:03:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591729403; bh=Vfyj+NMf8T/7CXC12HCXGIpKKfBA7HOZ+MDv198zK9s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pxu1syBzHoL2J5cnIy7N/PAPPSbc4BdrkkQHcs1hT4yP8W7PbeAF1yOPCraK5p0Im h8LDblfbB+M4MWbEO1PeRBNmSlsTtVvX4+yyVmPZRqkX3FdPMwS5ViXdGuQnvAMdSs JPyIGOYHvSRzf3kfpUavxXOzx2hUYs/vTXODdywQ= Date: Tue, 9 Jun 2020 21:03:21 +0200 From: Greg Kroah-Hartman To: Naresh Kamboju Cc: open list , linux- stable , Linus Torvalds , Oleg Nesterov , 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: <20200609190321.GA1046130@kroah.com> References: <20200609174048.576094775@linuxfoundation.org> <20200609174051.488794266@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 10, 2020 at 12:25:56AM +0530, Naresh Kamboju wrote: > On Tue, 9 Jun 2020 at 23:35, Greg Kroah-Hartman > wrote: > > > > From: Oleg Nesterov > > > > commit 013b2deba9a6b80ca02f4fafd7dedf875e9b4450 upstream. > > > > uprobe_write_opcode() must not cross page boundary; prepare_uprobe() > > relies on arch_uprobe_analyze_insn() which should validate "vaddr" but > > some architectures (csky, s390, and sparc) don't do this. > > > > We can remove the BUG_ON() check in prepare_uprobe() and validate the > > offset early in __uprobe_register(). The new IS_ALIGNED() check matches > > the alignment check in arch_prepare_kprobe() on supported architectures, > > so I think that all insns must be aligned to UPROBE_SWBP_INSN_SIZE. > > > > Another problem is __update_ref_ctr() which was wrong from the very > > beginning, it can read/write outside of kmap'ed page unless "vaddr" is > > aligned to sizeof(short), __uprobe_register() should check this too. > > > > Reported-by: Linus Torvalds > > Suggested-by: Linus Torvalds > > Signed-off-by: Oleg Nesterov > > Reviewed-by: Srikar Dronamraju > > Acked-by: Christian Borntraeger > > Tested-by: Sven Schnelle > > Cc: Steven Rostedt > > Cc: stable@vger.kernel.org > > Signed-off-by: Linus Torvalds > > Signed-off-by: Greg Kroah-Hartman > > > > --- > > kernel/events/uprobes.c | 16 ++++++++++++---- > > 1 file changed, 12 insertions(+), 4 deletions(-) > > > > --- a/kernel/events/uprobes.c > > +++ b/kernel/events/uprobes.c > > @@ -612,10 +612,6 @@ static int prepare_uprobe(struct uprobe > > 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 the smp_rmb() in handle_swbp() */ > > set_bit(UPROBE_COPY_INSN, &uprobe->flags); > > > > @@ -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. greg k-h