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=-7.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED 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 71353C04AA5 for ; Mon, 15 Oct 2018 12:28:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D8062089D for ; Mon, 15 Oct 2018 12:28:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="xhxgr3u8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1D8062089D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726650AbeJOUNC (ORCPT ); Mon, 15 Oct 2018 16:13:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:57882 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726477AbeJOUNC (ORCPT ); Mon, 15 Oct 2018 16:13:02 -0400 Received: from devnote (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (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 B93F220652; Mon, 15 Oct 2018 12:27:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539606476; bh=auSy4bTOMYKNjeWeZavoZ3LgMModS2RYuwYJm6Gvkp8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=xhxgr3u8eHAnFW63NzL5V2k0m+8rza4YSMSOFgniG9TNAuoipD+IbFImttYSMxUds ziwM04yvKLiDxtG/Vc1/fxd5glwoCp7qRb/vg9w5XqqyWvjXwG3GiIHedT7LPTFGuZ tFq/PzQyUIM9N8BrLOl6TpWTrpt+bfsI1nMoxuRk= Date: Mon, 15 Oct 2018 21:27:53 +0900 From: Masami Hiramatsu To: Anders Roxell , Ard Biesheuvel Cc: Catalin Marinas , Will Deacon , linux-arm-kernel , Linux Kernel Mailing List , Arnd Bergmann , Laura Abbott Subject: Re: [PATCH] arm64: kprobe: make page to RO mode when allocate it Message-Id: <20181015212753.39e30fe38460fba455703309@kernel.org> In-Reply-To: References: <20181015111600.5479-1-anders.roxell@linaro.org> X-Mailer: Sylpheed 3.5.0 (GTK+ 2.24.30; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 15 Oct 2018 13:22:12 +0200 Ard Biesheuvel wrote: > (+ Masami) > > On 15 October 2018 at 13:16, Anders Roxell wrote: > > Commit 1404d6f13e47 ("arm64: dump: Add checking for writable and exectuable pages") > > has successfully identified code that leaves a page with W+X > > permissions. > > > > [ 3.245140] arm64/mm: Found insecure W+X mapping at address (____ptrval____)/0xffff000000d90000 > > [ 3.245771] WARNING: CPU: 0 PID: 1 at ../arch/arm64/mm/dump.c:232 note_page+0x410/0x420 > > [ 3.246141] Modules linked in: > > [ 3.246653] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc5-next-20180928-00001-ge70ae259b853-dirty #62 > > [ 3.247008] Hardware name: linux,dummy-virt (DT) > > [ 3.247347] pstate: 80000005 (Nzcv daif -PAN -UAO) > > [ 3.247623] pc : note_page+0x410/0x420 > > [ 3.247898] lr : note_page+0x410/0x420 > > [ 3.248071] sp : ffff00000804bcd0 > > [ 3.248254] x29: ffff00000804bcd0 x28: ffff000009274000 > > [ 3.248578] x27: ffff00000921a000 x26: ffff80007dfff000 > > [ 3.248845] x25: ffff0000093f5000 x24: ffff000009526f6a > > [ 3.249109] x23: 0000000000000004 x22: ffff000000d91000 > > [ 3.249396] x21: ffff000000d90000 x20: 0000000000000000 > > [ 3.249661] x19: ffff00000804bde8 x18: 0000000000000400 > > [ 3.249924] x17: 0000000000000000 x16: 0000000000000000 > > [ 3.250271] x15: ffffffffffffffff x14: 295f5f5f5f6c6176 > > [ 3.250594] x13: 7274705f5f5f5f28 x12: 2073736572646461 > > [ 3.250941] x11: 20746120676e6970 x10: 70616d20582b5720 > > [ 3.251252] x9 : 6572756365736e69 x8 : 3039643030303030 > > [ 3.251519] x7 : 306666666678302f x6 : ffff0000095467b2 > > [ 3.251802] x5 : 0000000000000000 x4 : 0000000000000000 > > [ 3.252060] x3 : 0000000000000000 x2 : ffffffffffffffff > > [ 3.252323] x1 : 4d151327adc50b00 x0 : 0000000000000000 > > [ 3.252664] Call trace: > > [ 3.252953] note_page+0x410/0x420 > > [ 3.253186] walk_pgd+0x12c/0x238 > > [ 3.253417] ptdump_check_wx+0x68/0xf8 > > [ 3.253637] mark_rodata_ro+0x68/0x98 > > [ 3.253847] kernel_init+0x38/0x160 > > [ 3.254103] ret_from_fork+0x10/0x18 > > > > Reworked to that when allocate a page it sets mode RO. Inspired by > > commit 63fef14fc98a ("kprobes/x86: Make insn buffer always ROX and use text_poke()"). Yeah, that looks similar issue on x86, and looks good to me. Thank you for fixing it! Acked-by: Masami Hiramatsu > > > > Cc: Arnd Bergmann > > Cc: Ard Biesheuvel > > Cc: Laura Abbott > > Cc: Catalin Marinas > > Co-developed-by: Arnd Bergmann > > Co-developed-by: Ard Biesheuvel > > Signed-off-by: Anders Roxell > > --- > > arch/arm64/kernel/probes/kprobes.c | 27 ++++++++++++++++++++------- > > 1 file changed, 20 insertions(+), 7 deletions(-) > > > > diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c > > index 9b65132e789a..b842e908b423 100644 > > --- a/arch/arm64/kernel/probes/kprobes.c > > +++ b/arch/arm64/kernel/probes/kprobes.c > > @@ -23,7 +23,9 @@ > > #include > > #include > > #include > > +#include > > #include > > +#include > > #include > > #include > > #include > > @@ -42,10 +44,21 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); > > static void __kprobes > > post_kprobe_handler(struct kprobe_ctlblk *, struct pt_regs *); > > > > +static int __kprobes patch_text(kprobe_opcode_t *addr, u32 opcode) > > +{ > > + void *addrs[1]; > > + u32 insns[1]; > > + > > + addrs[0] = (void *)addr; > > + insns[0] = (u32)opcode; > > + > > + return aarch64_insn_patch_text(addrs, insns, 1); > > +} > > + > > static void __kprobes arch_prepare_ss_slot(struct kprobe *p) > > { > > /* prepare insn slot */ > > - p->ainsn.api.insn[0] = cpu_to_le32(p->opcode); > > + patch_text(p->ainsn.api.insn, p->opcode); > > > > flush_icache_range((uintptr_t) (p->ainsn.api.insn), > > (uintptr_t) (p->ainsn.api.insn) + > > @@ -118,15 +131,15 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) > > return 0; > > } > > > > -static int __kprobes patch_text(kprobe_opcode_t *addr, u32 opcode) > > +void *alloc_insn_page(void) > > { > > - void *addrs[1]; > > - u32 insns[1]; > > + void *page; > > > > - addrs[0] = (void *)addr; > > - insns[0] = (u32)opcode; > > + page = vmalloc_exec(PAGE_SIZE); > > + if (page) > > + set_memory_ro((unsigned long)page & PAGE_MASK, 1); > > > > - return aarch64_insn_patch_text(addrs, insns, 1); > > + return page; > > } > > > > /* arm kprobe: install breakpoint in text */ > > -- > > 2.19.1 > > -- Masami Hiramatsu