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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03783C433F5 for ; Mon, 13 Dec 2021 04:22:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231710AbhLMEWg (ORCPT ); Sun, 12 Dec 2021 23:22:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229947AbhLMEWf (ORCPT ); Sun, 12 Dec 2021 23:22:35 -0500 Received: from mail-pf1-x431.google.com (mail-pf1-x431.google.com [IPv6:2607:f8b0:4864:20::431]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A2D0C06173F for ; Sun, 12 Dec 2021 20:22:35 -0800 (PST) Received: by mail-pf1-x431.google.com with SMTP id u80so13818592pfc.9 for ; Sun, 12 Dec 2021 20:22:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=9hc37yVx4b3sSyB7F9HIij1MIdsw+3eTqd5pJUwPWDA=; b=GZ2wXTZQc6dPO7fg2/OOkUco8Uzp/P8uEegXpceqTq0MArY/U0mknOXpsXZu2qh7Ef NseujPsgTeGgzNTn6D3oyq8NFAk9ktZPlM89bSETFq2N0ioXKSP9TDgvs5Okf+pAvWu9 2iQJkIkLf9q6vFpKx5Ykkx6+hwseCIM1yChJ22xPe3xsRV5ImpQR2chxNAFzKIuB1/ts OyYQbx8anu3+EsNaHbwcjirB5IWwpaYQ5KW9eKhqaN7CaVEAZL0D6LVa82fnlA4eHd/E AEK2CAFm3XnsAZQEKZlyEL5NbQgMXlA54RSusPTeQcfQefSSWYAFTPA6DW5Hg1aQnflA 2IPA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=9hc37yVx4b3sSyB7F9HIij1MIdsw+3eTqd5pJUwPWDA=; b=qbr5X9ERvaqIA19PM3DrTA+ffzpjW9SoCnoPqy96AwxBMcmS2xnVXa4iZHairVkTHH i4B1QlSlltIhWT9iMGZa7BYblcED9bH9wEKIi+0uHqqrgOzbvfi21HU/H5ZE/TD6l3Qn tMlsYn5Z+dupwEndj9dySMicrugtkESL7EXBQ7GHvAGLYrZoLzwsp+XRQp6jVqjt17+u x5NODeklLGDd9dvtRoN+B5FtvdqU3DxRP8R5uGpzNiMNMT3DdYMB5MWlpd/liDNV1Vl4 xBwC8BFVK3IiEQT1PIEtvaxidBV/fvkwujhRy5G7pT5WJ4VQMMUPh0PV6E23NAmg02jA T0Bg== X-Gm-Message-State: AOAM530ZFuYH7NnfE3qtkXIeFTWnN9e05A6SuQ8GkbrJmdSDPMhMZymB bLriiPgEqQOTFUoyKIesKoBdLfyIZ3SulA== X-Google-Smtp-Source: ABdhPJwsZi6J9kwwvIur8TGZ2I9sK60sPlQu7YwqD5snPQiaYoeX+vlyxOcdPrLp+cs0opeRBTNtjg== X-Received: by 2002:a05:6a00:bcd:b0:4b0:62ef:c6af with SMTP id x13-20020a056a000bcd00b004b062efc6afmr21850382pfu.39.1639369354741; Sun, 12 Dec 2021 20:22:34 -0800 (PST) Received: from localhost ([47.88.60.64]) by smtp.gmail.com with ESMTPSA id h1sm10387529pfi.217.2021.12.12.20.22.33 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sun, 12 Dec 2021 20:22:34 -0800 (PST) From: Lai Jiangshan To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, Lai Jiangshan , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Oleg Nesterov , "Chang S. Bae" , Jan Kiszka , Joerg Roedel Subject: [PATCH 3/3] x86/sev: The code for returning to user space is also in syscall gap Date: Mon, 13 Dec 2021 12:22:15 +0800 Message-Id: <20211213042215.3096-4-jiangshanlai@gmail.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: <20211213042215.3096-1-jiangshanlai@gmail.com> References: <20211213042215.3096-1-jiangshanlai@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lai Jiangshan When returning to user space, the %rsp is user controlled value. Signed-off-by: Lai Jiangshan --- arch/x86/entry/entry_64.S | 2 ++ arch/x86/entry/entry_64_compat.S | 2 ++ arch/x86/include/asm/proto.h | 4 ++++ arch/x86/include/asm/ptrace.h | 4 ++++ 4 files changed, 12 insertions(+) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index e23319ad3f42..44dadea935f7 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -213,8 +213,10 @@ syscall_return_via_sysret: popq %rdi popq %rsp +SYM_INNER_LABEL(entry_SYSRETQ_unsafe_stack, SYM_L_GLOBAL) swapgs sysretq +SYM_INNER_LABEL(entry_SYSRETQ_end, SYM_L_GLOBAL) SYM_CODE_END(entry_SYSCALL_64) /* diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index 0051cf5c792d..98afdf92f360 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -293,6 +293,7 @@ sysret32_from_system_call: * code. We zero R8-R10 to avoid info leaks. */ movq RSP-ORIG_RAX(%rsp), %rsp +SYM_INNER_LABEL(entry_SYSRETL_compat_unsafe_stack, SYM_L_GLOBAL) /* * The original userspace %rsp (RSP-ORIG_RAX(%rsp)) is stored @@ -310,6 +311,7 @@ sysret32_from_system_call: xorl %r10d, %r10d swapgs sysretl +SYM_INNER_LABEL(entry_SYSRETL_compat_end, SYM_L_GLOBAL) SYM_CODE_END(entry_SYSCALL_compat) /* diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h index feed36d44d04..f042cfc9938f 100644 --- a/arch/x86/include/asm/proto.h +++ b/arch/x86/include/asm/proto.h @@ -13,6 +13,8 @@ void syscall_init(void); #ifdef CONFIG_X86_64 void entry_SYSCALL_64(void); void entry_SYSCALL_64_safe_stack(void); +void entry_SYSRETQ_unsafe_stack(void); +void entry_SYSRETQ_end(void); long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2); #endif @@ -28,6 +30,8 @@ void entry_SYSENTER_compat(void); void __end_entry_SYSENTER_compat(void); void entry_SYSCALL_compat(void); void entry_SYSCALL_compat_safe_stack(void); +void entry_SYSRETL_compat_unsafe_stack(void); +void entry_SYSRETL_compat_end(void); void entry_INT80_compat(void); #ifdef CONFIG_XEN_PV void xen_entry_INT80_compat(void); diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index 703663175a5a..b3d2ba13cee2 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -186,9 +186,13 @@ static __always_inline bool ip_within_syscall_gap(struct pt_regs *regs) bool ret = (regs->ip >= (unsigned long)entry_SYSCALL_64 && regs->ip < (unsigned long)entry_SYSCALL_64_safe_stack); + ret = ret || (regs->ip >= (unsigned long)entry_SYSRETQ_unsafe_stack && + regs->ip < (unsigned long)entry_SYSRETQ_end); #ifdef CONFIG_IA32_EMULATION ret = ret || (regs->ip >= (unsigned long)entry_SYSCALL_compat && regs->ip < (unsigned long)entry_SYSCALL_compat_safe_stack); + ret = ret || (regs->ip >= (unsigned long)entry_SYSRETL_compat_unsafe_stack && + regs->ip < (unsigned long)entry_SYSRETL_compat_end); #endif return ret; -- 2.19.1.6.gb485710b