From patchwork Fri Jan 31 06:17:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11359351 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 34D0192A for ; Fri, 31 Jan 2020 06:17:14 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 019802253D for ; Fri, 31 Jan 2020 06:17:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Pp1HYmBr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 019802253D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8A08F6B0597; Fri, 31 Jan 2020 01:17:12 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 851966B0599; Fri, 31 Jan 2020 01:17:12 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7676C6B059A; Fri, 31 Jan 2020 01:17:12 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0030.hostedemail.com [216.40.44.30]) by kanga.kvack.org (Postfix) with ESMTP id 544586B0597 for ; Fri, 31 Jan 2020 01:17:12 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 1C344181AEF0B for ; Fri, 31 Jan 2020 06:17:12 +0000 (UTC) X-FDA: 76436921904.12.beds88_3ed37412e8b13 X-Spam-Summary: 2,0,0,8a9fc1bf280e64f8,d41d8cd98f00b204,akpm@linux-foundation.org,:adobriyan@gmail.com:akpm@linux-foundation.org::mm-commits@vger.kernel.org:torvalds@linux-foundation.org,RULES_HIT:41:355:379:800:960:967:973:988:989:1260:1263:1345:1359:1381:1431:1437:1534:1541:1711:1730:1747:1777:1792:2393:2525:2553:2559:2563:2682:2685:2693:2859:2898:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3352:3865:3866:3867:3868:3871:3872:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4250:4321:4605:5007:6261:6653:7514:7576:8599:8603:9025:9040:9545:10004:10913:11026:11473:11658:11914:12043:12048:12296:12297:12517:12519:12555:12679:12696:12737:12783:12986:13069:13161:13229:13255:13311:13357:13972:14096:14181:14384:14721:21080:21220:21451:21627:21939:21990:30003:30045:30054:30070:30090,0,RBL:198.145.29.99:@linux-foundation.org:.lbl8.mailshell.net-62.2.0.100 64.100.201.201,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSB L:0,DNSB X-HE-Tag: beds88_3ed37412e8b13 X-Filterd-Recvd-Size: 3014 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf32.hostedemail.com (Postfix) with ESMTP for ; Fri, 31 Jan 2020 06:17:11 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (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 D3F672173E; Fri, 31 Jan 2020 06:17:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580451431; bh=Db5K6G3Yx6IXELl53WZciAGH2lNNY4+QbyShPNE9/30=; h=Date:From:To:Subject:In-Reply-To:From; b=Pp1HYmBr1TLYYrmC8LfWYDWjTiCVGIKDJFSBCF+7kDz+yULjQ5xpRnlqLhOz/vq+H 2TcCEL0gBocgIzOI1LcNCEO7aOfA03lAF8rUAeShVeW84wWTNO84vI0gjyNJDd8B8W 6Szg7pJxGeuaXIasLhTHgYuyQQqiHJjljWKEKLB0= Date: Thu, 30 Jan 2020 22:17:10 -0800 From: Andrew Morton To: adobriyan@gmail.com, akpm@linux-foundation.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 110/118] fs/binfmt_elf.c: coredump: allow process with empty address space to coredump Message-ID: <20200131061710.rGdjO2hok%akpm@linux-foundation.org> In-Reply-To: <20200130221021.5f0211c56346d5485af07923@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Alexey Dobriyan Subject: fs/binfmt_elf.c: coredump: allow process with empty address space to coredump Unmapping whole address space at once with munmap(0, (1ULL<<47) - 4096) or equivalent will create empty coredump. It is silly way to exit, however registers content may still be useful. The right to coredump is fundamental right of a process! Link: http://lkml.kernel.org/r/20191222150137.GA1277@avx2 Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton --- fs/binfmt_elf.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/fs/binfmt_elf.c~elf-coredump-allow-process-with-empty-address-space-to-coredump +++ a/fs/binfmt_elf.c @@ -1595,6 +1595,10 @@ static int fill_files_note(struct memelf if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */ return -EINVAL; size = round_up(size, PAGE_SIZE); + /* + * "size" can be 0 here legitimately. + * Let it ENOMEM and omit NT_FILE section which will be empty anyway. + */ data = kvmalloc(size, GFP_KERNEL); if (ZERO_OR_NULL_PTR(data)) return -ENOMEM; @@ -2257,9 +2261,13 @@ static int elf_core_dump(struct coredump dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); + /* + * Zero vma process will get ZERO_SIZE_PTR here. + * Let coredump continue for register state at least. + */ vma_filesz = kvmalloc(array_size(sizeof(*vma_filesz), (segs - 1)), GFP_KERNEL); - if (ZERO_OR_NULL_PTR(vma_filesz)) + if (!vma_filesz) goto end_coredump; for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;