From patchwork Fri Aug 2 17:02:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cristian Marussi X-Patchwork-Id: 11073969 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 10CD013B1 for ; Fri, 2 Aug 2019 17:05:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 02777288B8 for ; Fri, 2 Aug 2019 17:05:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EA8E6288B9; Fri, 2 Aug 2019 17:05:20 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 6E38E288B6 for ; Fri, 2 Aug 2019 17:05:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=+m8Mi8MnSxa27TeqFuu91akxipB9BFchGCPlkaK1SJg=; b=EvrIL1Meow8ct6GNoW1FepNnEx gpAeE+nOoSRgm/T6ujBRhDmAHvYWfyYeH6S9QQFbUMuE9gFgHlTO/Zm0PHLoeHLiL2HEyjaSrrRp0 b6JwZWdtxHf25wjGkqB7Xjc+ne7tzMsCbXJPRXhktBgVTCHUM1xfEpNVDRoNVYLaI8Ja+hW42ljqd ZFqIhCTZssbOb260IaY9eTWcmBmxEuDgjcogHPqcTpezGowTsCcZrXUDu/9iJ3H2iNprQI5/Wk6I+ Bygd0GlFSR6xNQMf39G15RhXx5NOYk35GDp9OKYfjjOTZope1FQ1hvuTuJXCVlITKd8TVZmqVBgrL LbT2FTIg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1htazX-0005tG-3y; Fri, 02 Aug 2019 17:05:19 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1htaxx-0002EK-Nq for linux-arm-kernel@lists.infradead.org; Fri, 02 Aug 2019 17:03:43 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E7D37344; Fri, 2 Aug 2019 10:03:40 -0700 (PDT) Received: from e120937-lin.cambridge.arm.com (e120937-lin.cambridge.arm.com [10.1.197.50]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 26A0B3F575; Fri, 2 Aug 2019 10:03:40 -0700 (PDT) From: Cristian Marussi To: linux-kselftest@vger.kernel.org, linux-arm-kernel@lists.infradead.org, shuah@kernel.org Subject: [PATCH v3 10/11] kselftest: arm64: fake_sigreturn_bad_size Date: Fri, 2 Aug 2019 18:02:59 +0100 Message-Id: <20190802170300.20662-11-cristian.marussi@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190802170300.20662-1-cristian.marussi@arm.com> References: <20190802170300.20662-1-cristian.marussi@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190802_100341_930849_641B02FB X-CRM114-Status: GOOD ( 14.61 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: andreyknvl@google.com, dave.martin@arm.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Added a simple fake_sigreturn testcase which builds a ucontext_t with a badly sized header that causes a overrun in the __reserved area and place it onto the stack. Expects a SIGSEGV on test PASS. Signed-off-by: Cristian Marussi --- .../arm64/signal/testcases/.gitignore | 1 + .../testcases/fake_sigreturn_bad_size.c | 85 +++++++++++++++++++ 2 files changed, 86 insertions(+) create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size.c diff --git a/tools/testing/selftests/arm64/signal/testcases/.gitignore b/tools/testing/selftests/arm64/signal/testcases/.gitignore index 94f9baaf638c..3408e0f5ba98 100644 --- a/tools/testing/selftests/arm64/signal/testcases/.gitignore +++ b/tools/testing/selftests/arm64/signal/testcases/.gitignore @@ -8,3 +8,4 @@ fake_sigreturn_bad_magic fake_sigreturn_bad_size_for_magic0 fake_sigreturn_missing_fpsimd fake_sigreturn_duplicated_fpsimd +fake_sigreturn_bad_size diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size.c new file mode 100644 index 000000000000..1467fb534d8b --- /dev/null +++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size.c @@ -0,0 +1,85 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) 2019 ARM Limited */ + +#include +#include + +#include "test_signals_utils.h" +#include "testcases.h" + +struct fake_sigframe sf; + +#define MIN_SZ_ALIGN 16 + +static int fake_sigreturn_bad_size_run(struct tdescr *td, + siginfo_t *si, ucontext_t *uc) +{ + size_t resv_sz, need_sz, offset; + struct _aarch64_ctx *shead = GET_SF_RESV_HEAD(sf), *head; + + /* just to fill the ucontext_t with something real */ + if (!get_current_context(td, &sf.uc)) + return 1; + + resv_sz = GET_SF_RESV_SIZE(sf); + /* + * find the terminator, preserving existing headers + * and verify amount of spare room in __reserved area. + */ + head = get_terminator(shead, resv_sz, &offset); + /* + * try stripping extra_context header when low on space: + * we need at least for the bad sized esr_context. + */ + need_sz = HDR_SZ + sizeof(struct esr_context); + if (head && resv_sz - offset < need_sz) { + fprintf(stderr, "Low on space:%zd. Discarding extra_context.\n", + resv_sz - offset); + head = get_header(shead, EXTRA_MAGIC, resv_sz, &offset); + } + /* just give up and timeout if still not enough space */ + if (head && resv_sz - offset >= need_sz) { + fprintf(stderr, "Mangling template header. Spare space:%zd\n", + resv_sz - offset); + /* + * Use an esr_context to build a fake header with a + * size greater then the free __reserved area minus HDR_SZ; + * using ESR_MAGIC here since it is not checked for size nor + * is limited to one instance. + * + * At first inject an additional normal esr_context + */ + head->magic = ESR_MAGIC; + head->size = sizeof(struct esr_context); + /* and terminate properly */ + write_terminator_record(GET_RESV_NEXT_HEAD(head)); + ASSERT_GOOD_CONTEXT(&sf.uc); + + /* + * now mess with fake esr_context size: leaving less space than + * neededwhile keeping size value 16-aligned + * + * It must trigger a SEGV from Kernel on: + * + * resv_sz - offset < sizeof(*head) + */ + /* at first set the maximum good 16-aligned size */ + head->size = (resv_sz - offset - need_sz + MIN_SZ_ALIGN) & ~0xfUL; + /* plus a bit more of 16-aligned sized stuff */ + head->size += MIN_SZ_ALIGN; + /* and terminate properly */ + write_terminator_record(GET_RESV_NEXT_HEAD(head)); + ASSERT_BAD_CONTEXT(&sf.uc); + fake_sigreturn(&sf, sizeof(sf), 16); + } + + return 1; +} + +struct tdescr tde = { + .name = "FAKE_SIGRETURN_BAD_SIZE", + .descr = "Triggers a fake sigreturn with a sigframe including a badly sized header which overruns the __reserved area", + .sig_ok = SIGSEGV, + .timeout = 3, + .run = fake_sigreturn_bad_size_run, +};