From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Fri, 2 Nov 2018 17:31:59 +0000 Subject: [PATCH v2] arm64: kprobe: make page to RO mode when allocate it In-Reply-To: <20181030113850.31150-1-anders.roxell@linaro.org> References: <20181030113850.31150-1-anders.roxell@linaro.org> Message-ID: <20181102173159.GG218059@arrakis.emea.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Oct 30, 2018 at 12:38:50PM +0100, 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 > > kprobes allocates a writable executable page with module_alloc() in > order to store executable code. > 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()"). > > Cc: Laura Abbott > Cc: Catalin Marinas > Co-developed-by: Arnd Bergmann > Co-developed-by: Ard Biesheuvel > Signed-off-by: Arnd Bergmann > Signed-off-by: Ard Biesheuvel > Signed-off-by: Anders Roxell Queued for 4.20 (and removed the signed-off-bys, added acks, removed unnecessary casts). Thanks. -- Catalin 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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 AB423C32789 for ; Fri, 2 Nov 2018 17:32:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 61A4920831 for ; Fri, 2 Nov 2018 17:32:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 61A4920831 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com 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 S1728029AbeKCCj7 (ORCPT ); Fri, 2 Nov 2018 22:39:59 -0400 Received: from foss.arm.com ([217.140.101.70]:44416 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726085AbeKCCj7 (ORCPT ); Fri, 2 Nov 2018 22:39:59 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 984A3A78; Fri, 2 Nov 2018 10:32:03 -0700 (PDT) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.197.53]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0FACB3F71E; Fri, 2 Nov 2018 10:32:01 -0700 (PDT) Date: Fri, 2 Nov 2018 17:31:59 +0000 From: Catalin Marinas To: Anders Roxell Cc: will.deacon@arm.com, masami.hiramatsu@linaro.org, Arnd Bergmann , Ard Biesheuvel , linux-kernel@vger.kernel.org, Laura Abbott , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2] arm64: kprobe: make page to RO mode when allocate it Message-ID: <20181102173159.GG218059@arrakis.emea.arm.com> References: <20181030113850.31150-1-anders.roxell@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181030113850.31150-1-anders.roxell@linaro.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 30, 2018 at 12:38:50PM +0100, 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 > > kprobes allocates a writable executable page with module_alloc() in > order to store executable code. > 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()"). > > Cc: Laura Abbott > Cc: Catalin Marinas > Co-developed-by: Arnd Bergmann > Co-developed-by: Ard Biesheuvel > Signed-off-by: Arnd Bergmann > Signed-off-by: Ard Biesheuvel > Signed-off-by: Anders Roxell Queued for 4.20 (and removed the signed-off-bys, added acks, removed unnecessary casts). Thanks. -- Catalin