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J . Lu" , Yu-cheng Yu , Kees Cook , Eric Biederman , linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, libc-alpha@sourceware.org, Mark Brown Subject: [PATCH v13 0/2] arm64: Enable BTI for the executable as well as the interpreter Date: Tue, 19 Apr 2022 11:51:54 +0100 Message-Id: <20220419105156.347168-1-broonie@kernel.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2110; h=from:subject; bh=Kps/nxXdvPmFXoUlorRs+A7ltjd1wVHQC8NezFMOSIE=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBiXpRJcfio29GZoxSti3bpnKc41Y8y84J37Pv6Tfyd ZJzwHuiJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCYl6USQAKCRAk1otyXVSH0HFoB/ wJVd2GkOxINUznTSbBRQrTn7aErJQuxDfrnxxIUuz5e4u5Ch2h/G/zyIq736my/GfE619j+hJsCmzO Xl5zl4F6l+WOeobRpHCtOt7gUHdGlXJLQbAWhaEIFzZ2RQZRMc9JJ/YYo6TcZERutsIDdYBXUXfMiX TgooicRZ4bErr3yEcfFUlEFnZVrfec0l9aFLpOSfK2QFQBZs9Hsn+yWyZ31/7oTzVvuHsp2OTYVqsa NRcpH9Wyp2esgbjcw1v/hbwxvddO1K4CKGokpZC6eVLYdobt+hxetNJl8QRzT2BL36IUbi+iQdXGu4 haUUXsU5oBv32Ji2i/lxBRE+JkgARk X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org Deployments of BTI on arm64 have run into issues interacting with systemd's MemoryDenyWriteExecute feature. Currently for dynamically linked executables the kernel will only handle architecture specific properties like BTI for the interpreter, the expectation is that the interpreter will then handle any properties on the main executable. For BTI this means remapping the executable segments PROT_EXEC | PROT_BTI. This interacts poorly with MemoryDenyWriteExecute since that is implemented using a seccomp filter which prevents setting PROT_EXEC on already mapped memory and lacks the context to be able to detect that memory is already mapped with PROT_EXEC. This series resolves this by providing a sysctl which when enabled will cause the kernel to handle the BTI property for both the interpreter and the main executable. v13: - Rebase onto v5.18-rc3. v12: - Rebase onto v5.18-rc1. v11: - Ignore extra PT_INTERPs. v10: - Add a sysctl abi.bti_main controlling the new behaviour. v9: - Rebase onto v5.17-rc3. v8: - Rebase onto v5.17-rc1. v7: - Rebase onto v5.16-rc1. v6: - Rebase onto v5.15-rc1. v5: - Rebase onto v5.14-rc2. - Tweak changelog on patch 1. - Use the helper for interpreter/executable flag in elf.h as well. v4: - Rebase onto v5.14-rc1. v3: - Fix passing of properties for parsing by the main executable. - Drop has_interp from arch_parse_elf_property(). - Coding style tweaks. v2: - Add a patch dropping has_interp from arch_adjust_elf_prot() - Fix bisection issue with static executables on arm64 in the first patch. Mark Brown (2): elf: Allow architectures to parse properties on the main executable arm64: Enable BTI for main executable as well as the interpreter arch/arm64/include/asm/elf.h | 14 ++++++++-- arch/arm64/kernel/process.c | 52 +++++++++++++++++++++++++++--------- fs/binfmt_elf.c | 34 ++++++++++++++++------- include/linux/elf.h | 4 ++- 4 files changed, 78 insertions(+), 26 deletions(-) base-commit: b2d229d4ddb17db541098b83524d901257e93845 -- 2.30.2 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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 33D4EC433EF for ; Tue, 19 Apr 2022 10:53:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=fS1IC4kc7YmckJVbu6CgFgy7OGswmTBvWfhcDL2Gbek=; b=gxv2j+6c4mHg85 yLKCm7n0vF156bwpxVzso279VHFyMjcvrCvDxK2V2xvjnczMmTOzSwyENZyQc4Kn6lXLAi53wSajZ h5lZIZQR0uctFzEUPGfoiHkSjnuAT74NCWfQP4q1cX3TXslpRp2ggTePoqa+tOgiWNpEqHcRDgGM0 zCFXNTWshQ3G+Z+Xtk3jA7tqg04Qsv15fSlTSQ3euAda61ufIJeDAv+TtVzysn/XwdAIMdzmpZpGE yF41OTcLsFr+9tm7lOuXbAMbFQUsbtPaysIVbVZypSoyqcks7vIM+dsPp7MhLLZivnTASNmUfEvmJ EAg8Q0Vh0lo/Ca/UtkdA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nglSz-002vYJ-Bq; Tue, 19 Apr 2022 10:52:18 +0000 Received: from ams.source.kernel.org ([2604:1380:4601:e00::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nglSo-002vVU-AR for linux-arm-kernel@lists.infradead.org; Tue, 19 Apr 2022 10:52:08 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 33833B816A6; Tue, 19 Apr 2022 10:52:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 73DCFC385A7; Tue, 19 Apr 2022 10:52:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1650365523; bh=Kps/nxXdvPmFXoUlorRs+A7ltjd1wVHQC8NezFMOSIE=; h=From:To:Cc:Subject:Date:From; b=cJUaGD0gfHALC3Vhq3GC8+GrBlknI/gbREJ1bPrY2fQajjQ+NhUMlvO26h3bobeVz FtzRloQyq06Zxvf72SEcZg72R5weY4oJa8e6xEG+1oCgOLS8kLAqvTA+T4I1Wy+Y9i gUQxcZiextfbGnMiIzLNiyHcOuINMU8xy9bTy6HK7NABTYaFZE5IRlJVmUxITPHLzM 11fO0IAlLKYZbUdnuhlK3pXSTPsBatTaI04JuvEIjjqxM/OkJ0pO1KlyzYKmlu5kg9 bvgMLi+42l9Y6sJpvubhJa6NLqSDgj8Uh/pij2U8/aIXjQJH7YrTReadhmcTHOU4x4 UDEkLcSrVODEg== From: Mark Brown To: Catalin Marinas , Will Deacon Cc: Szabolcs Nagy , Jeremy Linton , "H . J . Lu" , Yu-cheng Yu , Kees Cook , Eric Biederman , linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, libc-alpha@sourceware.org, Mark Brown Subject: [PATCH v13 0/2] arm64: Enable BTI for the executable as well as the interpreter Date: Tue, 19 Apr 2022 11:51:54 +0100 Message-Id: <20220419105156.347168-1-broonie@kernel.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2110; h=from:subject; bh=Kps/nxXdvPmFXoUlorRs+A7ltjd1wVHQC8NezFMOSIE=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBiXpRJcfio29GZoxSti3bpnKc41Y8y84J37Pv6Tfyd ZJzwHuiJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCYl6USQAKCRAk1otyXVSH0HFoB/ wJVd2GkOxINUznTSbBRQrTn7aErJQuxDfrnxxIUuz5e4u5Ch2h/G/zyIq736my/GfE619j+hJsCmzO Xl5zl4F6l+WOeobRpHCtOt7gUHdGlXJLQbAWhaEIFzZ2RQZRMc9JJ/YYo6TcZERutsIDdYBXUXfMiX TgooicRZ4bErr3yEcfFUlEFnZVrfec0l9aFLpOSfK2QFQBZs9Hsn+yWyZ31/7oTzVvuHsp2OTYVqsa NRcpH9Wyp2esgbjcw1v/hbwxvddO1K4CKGokpZC6eVLYdobt+hxetNJl8QRzT2BL36IUbi+iQdXGu4 haUUXsU5oBv32Ji2i/lxBRE+JkgARk X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220419_035206_721219_DDA3C860 X-CRM114-Status: GOOD ( 13.52 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Deployments of BTI on arm64 have run into issues interacting with systemd's MemoryDenyWriteExecute feature. Currently for dynamically linked executables the kernel will only handle architecture specific properties like BTI for the interpreter, the expectation is that the interpreter will then handle any properties on the main executable. For BTI this means remapping the executable segments PROT_EXEC | PROT_BTI. This interacts poorly with MemoryDenyWriteExecute since that is implemented using a seccomp filter which prevents setting PROT_EXEC on already mapped memory and lacks the context to be able to detect that memory is already mapped with PROT_EXEC. This series resolves this by providing a sysctl which when enabled will cause the kernel to handle the BTI property for both the interpreter and the main executable. v13: - Rebase onto v5.18-rc3. v12: - Rebase onto v5.18-rc1. v11: - Ignore extra PT_INTERPs. v10: - Add a sysctl abi.bti_main controlling the new behaviour. v9: - Rebase onto v5.17-rc3. v8: - Rebase onto v5.17-rc1. v7: - Rebase onto v5.16-rc1. v6: - Rebase onto v5.15-rc1. v5: - Rebase onto v5.14-rc2. - Tweak changelog on patch 1. - Use the helper for interpreter/executable flag in elf.h as well. v4: - Rebase onto v5.14-rc1. v3: - Fix passing of properties for parsing by the main executable. - Drop has_interp from arch_parse_elf_property(). - Coding style tweaks. v2: - Add a patch dropping has_interp from arch_adjust_elf_prot() - Fix bisection issue with static executables on arm64 in the first patch. Mark Brown (2): elf: Allow architectures to parse properties on the main executable arm64: Enable BTI for main executable as well as the interpreter arch/arm64/include/asm/elf.h | 14 ++++++++-- arch/arm64/kernel/process.c | 52 +++++++++++++++++++++++++++--------- fs/binfmt_elf.c | 34 ++++++++++++++++------- include/linux/elf.h | 4 ++- 4 files changed, 78 insertions(+), 26 deletions(-) base-commit: b2d229d4ddb17db541098b83524d901257e93845 -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel