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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD834C369DC for ; Thu, 1 May 2025 22:55:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2CF2D6B0089; Thu, 1 May 2025 18:55:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 146AF6B00AF; Thu, 1 May 2025 18:55:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E8BD86B00B0; Thu, 1 May 2025 18:55:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id C1EBF6B0089 for ; Thu, 1 May 2025 18:55:38 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id B84B61A1853 for ; Thu, 1 May 2025 22:55:39 +0000 (UTC) X-FDA: 83395847598.01.B8F372C Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) by imf21.hostedemail.com (Postfix) with ESMTP id 1FEEF1C0007 for ; Thu, 1 May 2025 22:55:37 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=vVr8rncf; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf21.hostedemail.com: domain of 36PsTaAoKCHcXcVibtpVigbjjbgZ.Xjhgdips-hhfqVXf.jmb@flex--changyuanl.bounces.google.com designates 209.85.214.201 as permitted sender) smtp.mailfrom=36PsTaAoKCHcXcVibtpVigbjjbgZ.Xjhgdips-hhfqVXf.jmb@flex--changyuanl.bounces.google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1746140138; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=QfJbN5pyiZqNm6v1VamUb2ZbseG+vyr/qmtYL/UOqAw=; b=6HlmtD7W03eQU8yF0TsWD8okYrhCn8sCghFKIMUBTkHsH/oF5grYKrSlv/RIjXeVs2pUmF LyOjnqeGBOsxjqRUU0vr/t239A5KbLjBriBxMPYEnrp61MUTH6ERSjy8s8CUxAsB5oObOi tgZizvNVEX6MAMwRSSK3+wRWjWIpywo= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1746140138; a=rsa-sha256; cv=none; b=pVbO2Wi9UaPKqOoBMzXY1wDl+md4Uy8xCIqe3Ffb3qTsROzxa+zpTpnReCRDXe+hj/nvqP yXvU6GvNLtlJynPWPlyO1pynf3XigH361fa3AX8byxqcp2J1ckRyFUJ8kwgTJrvPqeDjWz N0qbjMwIYLyvzno9K6n5bSoL+5UpCIk= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=vVr8rncf; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf21.hostedemail.com: domain of 36PsTaAoKCHcXcVibtpVigbjjbgZ.Xjhgdips-hhfqVXf.jmb@flex--changyuanl.bounces.google.com designates 209.85.214.201 as permitted sender) smtp.mailfrom=36PsTaAoKCHcXcVibtpVigbjjbgZ.Xjhgdips-hhfqVXf.jmb@flex--changyuanl.bounces.google.com Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-22406ee0243so10687795ad.3 for ; Thu, 01 May 2025 15:55:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1746140137; x=1746744937; darn=kvack.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=QfJbN5pyiZqNm6v1VamUb2ZbseG+vyr/qmtYL/UOqAw=; b=vVr8rncfauLdbV7YJFNsVrZKDdh7gcv5AkNUqhguHhT59VbdbSpSNTpKuYZKIyEsx8 0k8cbD6DTQicVwrJRSSXZcGZ50Y4MGtcOyIX7+D6dwYKYzkTqAOHE3/sMuU6w4SJBPLg HnXlvIhMoE3lB8040Dqs9FJMq0WoMCGV3Of4hTdLXJfFKxywj4MptSK02lp9kZEbD9Sq SPfqycrCU/yB5mjk6TmB9U6Pb+hl1FuV1Y5UpcJRfnscXuy1ZNxmblzfBx3A1Tqm1tbI H9Pksv76eoPjMt/M/0KgeiN3z7yT+fOIYrohzhIVM/FioQ/SVDuimNDiEIe0vG0aKXrV QFIQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1746140137; x=1746744937; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=QfJbN5pyiZqNm6v1VamUb2ZbseG+vyr/qmtYL/UOqAw=; b=OVKpP497pbbhDNcAQy+Cvbmn9QqyRok5Or5PH9R5DKeU+VP9jBr54YT50DOOR13ZX0 HEKAWSPoJ33fgc+iSwBoxbRxL8AVPxAvSS4zO2VnR+x/idbyBhRxyefRKvIBscfTcbsy KnR7kEuScnTiCDGKO7l1zlrbQt5CkZ61jMccv5YwiHcHICxmou0WIvt+WEvr2JbuFY2M xWxyNcUHPbokWFzfDie/juMWw98GIioMzljOvT7eW8JpnkQCRRCLIkucHETgHDHGXdwp wov+EMw4VXb8jfm6L5u4ARZLo6XDQ5piCsODgutuf29UlWV7vI27OLkcQMPlNiTOPe+D 8R7Q== X-Forwarded-Encrypted: i=1; AJvYcCUFN9Evym8h3jUOQ7z0ms7a9arto0KsmcxTYhxZfBygPnAytwAhleGPXOA/SCPQJMuL/rw0UgpUFg==@kvack.org X-Gm-Message-State: AOJu0Yx0wtDumwUIJx6PePosNhArKaMRDnsWPm6rfJ8rrSyFpk9zEcUy CzontNW+mpF5vGWdRHjN0pW/A53BfJtcRmWRfWEOKZz2DPwbNnted5LAN98odS7tvDnBHpvNmFI o9Xktykb6oDICyAMh7A== X-Google-Smtp-Source: AGHT+IEti7Jl7kPZOBgR2farF6AzrUQ71NZAgms5bozMIxOrugD7cn53XbT5cnCVAQHZeRCBz32iqnLauoNpF8Ul X-Received: from plac4.prod.google.com ([2002:a17:902:c2c4:b0:224:2ae9:b271]) (user=changyuanl job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:22d0:b0:22d:e458:96a5 with SMTP id d9443c01a7336-22e103d0471mr10540035ad.38.1746140136868; Thu, 01 May 2025 15:55:36 -0700 (PDT) Date: Thu, 1 May 2025 15:54:21 -0700 In-Reply-To: <20250501225425.635167-1-changyuanl@google.com> Mime-Version: 1.0 References: <20250501225425.635167-1-changyuanl@google.com> X-Mailer: git-send-email 2.49.0.906.g1f30a19c02-goog Message-ID: <20250501225425.635167-15-changyuanl@google.com> Subject: [PATCH v7 14/18] x86/boot: make sure KASLR does not step over KHO preserved memory From: Changyuan Lyu To: linux-kernel@vger.kernel.org Cc: changyuanl@google.com, akpm@linux-foundation.org, anthony.yznaga@oracle.com, arnd@arndb.de, ashish.kalra@amd.com, benh@kernel.crashing.org, bp@alien8.de, catalin.marinas@arm.com, corbet@lwn.net, dave.hansen@linux.intel.com, devicetree@vger.kernel.org, dwmw2@infradead.org, ebiederm@xmission.com, graf@amazon.com, hpa@zytor.com, jgowans@amazon.com, kexec@lists.infradead.org, krzk@kernel.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, luto@kernel.org, mark.rutland@arm.com, mingo@redhat.com, pasha.tatashin@soleen.com, pbonzini@redhat.com, peterz@infradead.org, ptyadav@amazon.de, robh@kernel.org, rostedt@goodmis.org, rppt@kernel.org, saravanak@google.com, skinsburskii@linux.microsoft.com, tglx@linutronix.de, thomas.lendacky@amd.com, will@kernel.org, x86@kernel.org Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 1FEEF1C0007 X-Rspam-User: X-Stat-Signature: 1sw8ftzdzn715d6ssgxsd9syehqx6rui X-HE-Tag: 1746140137-209247 X-HE-Meta: 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 o1AmIytq 8UR8QBRLHPTKu5tOf7XaXNt60ey0rn98OYCL2gvlCyz9vz71MFXZp2cCm8MGZ+l+I6S6p/dnwXWgh8AZIA4o5CNSS1APAE298PaNdA5FgHwI2vUDcVn7DhN7yc3FLgTGgQVhXtC40GZZ0cc07Ygpd34qDSoX/Q2sufAo7PieFYzVN8in+PAPeq8xiZTMToIeUK2Q9QKDWq3k1QhtS8nysifiUwf6uTxMplCXPswj5y+V5GaFTTil5CetN3VVyFFb/kXD9UHwrGZ9ce0ojjzNuXqg58HMnX3w7HX0o 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: List-Subscribe: List-Unsubscribe: From: Alexander Graf KHO uses "scratch regions" to bootstrap a kexec'ed kernel. These regions are guaranteed to not have any memory that KHO would preserve. Teach KASLR in decompression code to only consider these scratch regions when KHO is enabled to make sure preserved memory won't get overwritten. Signed-off-by: Alexander Graf Co-developed-by: Mike Rapoport (Microsoft) Signed-off-by: Mike Rapoport (Microsoft) Co-developed-by: Changyuan Lyu Signed-off-by: Changyuan Lyu --- arch/x86/boot/compressed/kaslr.c | 52 +++++++++++++++++++++++++++++++- 1 file changed, 51 insertions(+), 1 deletion(-) diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index f03d59ea6e40f..25de8c3e17cdb 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -760,6 +760,55 @@ static void process_e820_entries(unsigned long minimum, } } +/* + * If KHO is active, only process its scratch areas to ensure we are not + * stepping onto preserved memory. + */ +#ifdef CONFIG_KEXEC_HANDOVER +static bool process_kho_entries(unsigned long minimum, unsigned long image_size) +{ + struct kho_scratch *kho_scratch; + struct setup_data *ptr; + int i, nr_areas = 0; + + ptr = (struct setup_data *)boot_params_ptr->hdr.setup_data; + while (ptr) { + if (ptr->type == SETUP_KEXEC_KHO) { + struct kho_data *kho = (struct kho_data *)ptr->data; + + kho_scratch = (void *)kho->scratch_addr; + nr_areas = kho->scratch_size / sizeof(*kho_scratch); + + break; + } + + ptr = (struct setup_data *)ptr->next; + } + + if (!nr_areas) + return false; + + for (i = 0; i < nr_areas; i++) { + struct kho_scratch *area = &kho_scratch[i]; + struct mem_vector region = { + .start = area->addr, + .size = area->size, + }; + + if (process_mem_region(®ion, minimum, image_size)) + break; + } + + return true; +} +#else +static inline bool process_kho_entries(unsigned long minimum, + unsigned long image_size) +{ + return false; +} +#endif + static unsigned long find_random_phys_addr(unsigned long minimum, unsigned long image_size) { @@ -775,7 +824,8 @@ static unsigned long find_random_phys_addr(unsigned long minimum, return 0; } - if (!process_efi_entries(minimum, image_size)) + if (!process_kho_entries(minimum, image_size) && + !process_efi_entries(minimum, image_size)) process_e820_entries(minimum, image_size); phys_addr = slots_fetch_random(); -- 2.49.0.906.g1f30a19c02-goog