From nobody Sun Dec 14 21:34:14 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 56CD018FC8F for ; Thu, 16 Jan 2025 06:58:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737010728; cv=none; b=EYKhO5IjLyj1Rgjcpt7VvphSIzaFurcA3oIziTMRO0nPuxqCQNPWOYQBedgHrAvvgMqbxDMqGyiit9NJmRcyixCRdY0CnALDiUCHy8A7GCqJDacscZHkgrt2/5Me56nk5R0fTkrPTbbDbGvbtksrNF7/lJRIOVQtJQenAefcA/c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737010728; c=relaxed/simple; bh=0ssQhuDfl/5VpyiMqxSR0IwAfjRFUrcMVdKYNqGH8bE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hR1XcDnhY7/3hjm+Rezg1ZjZVWfSH9rKhLVTojFhXYJpYt3IPyqg7SZQ3l8IFTEuTy6wJXT0wwcNX8gb7f70GU1/14Vrkqr+vIgvuQH2vcs9cFqrXtagUnP58KAsMtsaawQsogJcvD8ybqJ1kOqH60EgoPT6fk7+Fi9N5M9fwB8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=WpxgOuUu; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WpxgOuUu" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1737010725; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=tQvCsR9EXSN3ga2DmGxkK/BjC0F26mqQj7WZLS4qcAw=; b=WpxgOuUuIM8LJgQZsVPl83qmdOsjFA/ydL5ruQCThydJ+nJtx8r0zz3PPWUnY9nQl0sDJJ MII/FN1/iGpRCo1rVhw0/qxi9OypGq5OegwoFXY1pLCdL5rB7yulu7c4hH+cRdZGmHg0O/ Q1tBK84f/5tkESTZxqTmxZQQ7gHEVQA= Received: from mail-pl1-f200.google.com (mail-pl1-f200.google.com [209.85.214.200]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-458-Jg0zh-v3PlKcZgNJ7g5yfQ-1; Thu, 16 Jan 2025 01:58:43 -0500 X-MC-Unique: Jg0zh-v3PlKcZgNJ7g5yfQ-1 X-Mimecast-MFC-AGG-ID: Jg0zh-v3PlKcZgNJ7g5yfQ Received: by mail-pl1-f200.google.com with SMTP id d9443c01a7336-21655569152so12614695ad.2 for ; Wed, 15 Jan 2025 22:58:43 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1737010720; x=1737615520; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=tQvCsR9EXSN3ga2DmGxkK/BjC0F26mqQj7WZLS4qcAw=; b=RucO+4G4yMfj5+wWHjgCWdNr4eCxsFL18+2QjSfbPdYcfRs9Pj/PehmmaPkZHlMGx7 1Si/7TN8E1v658N1MRkxgJRufY59ibe3zdNgmI97qB0/mV9RB2W/nKxJ68dugRreQo6k RyN4M2cLRLlSdACANopfy2WNRcoHLcg5377O7R8ncW4nKNc0Imce4b3koCTGIU5cNi/R OoQMbTWjlz5s3dM/5uaBOVchiri5U8qK2sD7jVGp2I8VXD6biq21RdX0xbzlbR46xbAd kUbN6cK6maaorWve1Xo+kbv5pOgcjoDaUzBYgJKKf+7wN8eXjyskwDd9sTbKceMXE1Mu ig5w== X-Forwarded-Encrypted: i=1; AJvYcCWDteEQ+6cpwwWkLDmONxmOJvtvTy0lql7VLVqmQO9JzTi2kP7yqkHy9Wcu6ZYUkP+Xzf+f5azI5v20BX0=@vger.kernel.org X-Gm-Message-State: AOJu0YwerztA+q1mnk+5HCy1XHv4c2sRlu1pV4u/k6rbOdMu76aBSjm4 PNuI1CjhlHoiZKiy8piiHhCGqGKAnTOoAauhXb6N1VaWe1UWLqJ2q60JUYuAjhRUh/xGD9A41sx aOJkXplMoYzMA+kUJAGRYLn+kL5ylcvpdYpn1oHZoqWr3U1eWYYY359WkLC8g6g== X-Gm-Gg: ASbGncsERgnke0Iw4MPAXaXwUXzIROqrf0IBiCnWk61M0pk6cdLMtfzoaAgFUyJ8TrJ rC5HlH7oxc7cZVYgZfwA8vmIxc19R9soQUAc06/X2zXKPRnuC7F958MgxANI6rd87k+/g37y5wH finhPYZDycKPv3CcNG0Hdliw12ROxiJLnvQV4e2ylDBp6epIC584TrxhD8VZ13Z1mVXVnJ8jItt +8J8UCzUqV19rU13DVR2Hh0vzug4B6SFwzx0xWnv8oadQZx X-Received: by 2002:a05:6a20:4325:b0:1e1:b062:f3fa with SMTP id adf61e73a8af0-1e88d1dba97mr60123649637.34.1737010720562; Wed, 15 Jan 2025 22:58:40 -0800 (PST) X-Google-Smtp-Source: AGHT+IF0mUbg5KfGVjWvvefswEmAHcx/8ryY08l4nYmf/QtfmhIT1/A0W8mtD2C6GcsE+LcNZkwPgw== X-Received: by 2002:a05:6a20:4325:b0:1e1:b062:f3fa with SMTP id adf61e73a8af0-1e88d1dba97mr60123596637.34.1737010720061; Wed, 15 Jan 2025 22:58:40 -0800 (PST) Received: from localhost ([43.228.180.230]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-72d40658efdsm10700322b3a.90.2025.01.15.22.58.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Jan 2025 22:58:39 -0800 (PST) From: Coiby Xu To: kexec@lists.infradead.org Cc: Ondrej Kozina , Milan Broz , Thomas Staudt , =?UTF-8?q?Daniel=20P=20=2E=20Berrang=C3=A9?= , Kairui Song , Jan Pazdziora , Pingfan Liu , Baoquan He , Dave Young , linux-kernel@vger.kernel.org, x86@kernel.org, Dave Hansen , Vitaly Kuznetsov , Vivek Goyal , Eric Biederman , Kees Cook , "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org (open list:KERNEL HARDENING (not covered by other areas):Keyword:\b__counted_by(_le|_be)?\b) Subject: [PATCH v7 3/7] crash_dump: store dm crypt keys in kdump reserved memory Date: Thu, 16 Jan 2025 14:58:18 +0800 Message-ID: <20250116065825.1041558-4-coxu@redhat.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250116065825.1041558-1-coxu@redhat.com> References: <20250116065825.1041558-1-coxu@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When the kdump kernel image and initrd are loaded, the dm crypts keys will be read from keyring and then stored in kdump reserved memory. Assume a key won't exceed 256 bytes thus MAX_KEY_SIZE=3D256 according to "cryptsetup benchmark". Signed-off-by: Coiby Xu --- include/linux/crash_core.h | 6 +- include/linux/kexec.h | 4 ++ kernel/crash_dump_dm_crypt.c | 129 +++++++++++++++++++++++++++++++++++ 3 files changed, 138 insertions(+), 1 deletion(-) diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h index 44305336314e..2e6782239034 100644 --- a/include/linux/crash_core.h +++ b/include/linux/crash_core.h @@ -34,7 +34,11 @@ static inline void arch_kexec_protect_crashkres(void) { } static inline void arch_kexec_unprotect_crashkres(void) { } #endif =20 - +#ifdef CONFIG_CRASH_DM_CRYPT +int crash_load_dm_crypt_keys(struct kimage *image); +#else +static inline int crash_load_dm_crypt_keys(struct kimage *image) {return 0= ; } +#endif =20 #ifndef arch_crash_handle_hotplug_event static inline void arch_crash_handle_hotplug_event(struct kimage *image, v= oid *arg) { } diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 61269e97502a..ec7504ba80e9 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -398,6 +398,10 @@ struct kimage { void *elf_headers; unsigned long elf_headers_sz; unsigned long elf_load_addr; + + /* dm crypt keys buffer */ + unsigned long dm_crypt_keys_addr; + unsigned long dm_crypt_keys_sz; }; =20 /* kexec interface functions */ diff --git a/kernel/crash_dump_dm_crypt.c b/kernel/crash_dump_dm_crypt.c index 62a3c47d8b3b..8c093c743d58 100644 --- a/kernel/crash_dump_dm_crypt.c +++ b/kernel/crash_dump_dm_crypt.c @@ -1,14 +1,62 @@ // SPDX-License-Identifier: GPL-2.0-only +#include +#include #include #include #include #include =20 #define KEY_NUM_MAX 128 /* maximum dm crypt keys */ +#define KEY_SIZE_MAX 256 /* maximum dm crypt key size */ #define KEY_DESC_MAX_LEN 128 /* maximum dm crypt key description size */ =20 static unsigned int key_count; =20 +struct dm_crypt_key { + unsigned int key_size; + char key_desc[KEY_DESC_MAX_LEN]; + u8 data[KEY_SIZE_MAX]; +}; + +static struct keys_header { + unsigned int total_keys; + struct dm_crypt_key keys[] __counted_by(total_keys); +} *keys_header; + +static size_t get_keys_header_size(size_t total_keys) +{ + return struct_size(keys_header, keys, total_keys); +} + +static int read_key_from_user_keying(struct dm_crypt_key *dm_key) +{ + const struct user_key_payload *ukp; + struct key *key; + + kexec_dprintk("Requesting key %s", dm_key->key_desc); + key =3D request_key(&key_type_logon, dm_key->key_desc, NULL); + + if (IS_ERR(key)) { + pr_warn("No such key %s\n", dm_key->key_desc); + return PTR_ERR(key); + } + + ukp =3D user_key_payload_locked(key); + if (!ukp) + return -EKEYREVOKED; + + if (ukp->datalen > KEY_SIZE_MAX) { + pr_err("Key size %u exceeds maximum (%u)\n", ukp->datalen, KEY_SIZE_MAX); + return -EINVAL; + } + + memcpy(dm_key->data, ukp->data, ukp->datalen); + dm_key->key_size =3D ukp->datalen; + kexec_dprintk("Get dm crypt key (size=3D%u) %s: %8ph\n", dm_key->key_size, + dm_key->key_desc, dm_key->data); + return 0; +} + struct config_key { struct config_item item; const char *description; @@ -130,6 +178,87 @@ static struct configfs_subsystem config_keys_subsys = =3D { }, }; =20 +static int build_keys_header(void) +{ + struct config_item *item =3D NULL; + struct config_key *key; + int i, r; + + if (keys_header !=3D NULL) + kvfree(keys_header); + + keys_header =3D kzalloc(get_keys_header_size(key_count), GFP_KERNEL); + if (!keys_header) + return -ENOMEM; + + keys_header->total_keys =3D key_count; + + i =3D 0; + list_for_each_entry(item, &config_keys_subsys.su_group.cg_children, + ci_entry) { + if (item->ci_type !=3D &config_key_type) + continue; + + key =3D to_config_key(item); + + strscpy(keys_header->keys[i].key_desc, key->description, + KEY_DESC_MAX_LEN); + r =3D read_key_from_user_keying(&keys_header->keys[i]); + if (r !=3D 0) { + kexec_dprintk("Failed to read key %s\n", + keys_header->keys[i].key_desc); + return r; + } + i++; + kexec_dprintk("Found key: %s\n", item->ci_name); + } + + return 0; +} + +int crash_load_dm_crypt_keys(struct kimage *image) +{ + struct kexec_buf kbuf =3D { + .image =3D image, + .buf_min =3D 0, + .buf_max =3D ULONG_MAX, + .top_down =3D false, + .random =3D true, + }; + int r; + + + if (key_count <=3D 0) { + kexec_dprintk("No dm-crypt keys\n"); + return -ENOENT; + } + + image->dm_crypt_keys_addr =3D 0; + r =3D build_keys_header(); + if (r) + return r; + + kbuf.buffer =3D keys_header; + kbuf.bufsz =3D get_keys_header_size(key_count); + + kbuf.memsz =3D kbuf.bufsz; + kbuf.buf_align =3D ELF_CORE_HEADER_ALIGN; + kbuf.mem =3D KEXEC_BUF_MEM_UNKNOWN; + r =3D kexec_add_buffer(&kbuf); + if (r) { + kvfree((void *)kbuf.buffer); + return r; + } + image->dm_crypt_keys_addr =3D kbuf.mem; + image->dm_crypt_keys_sz =3D kbuf.bufsz; + kexec_dprintk( + "Loaded dm crypt keys to kexec_buffer bufsz=3D0x%lx memsz=3D0x%lx\n", + kbuf.bufsz, kbuf.memsz); + + return r; +} + + static int __init configfs_dmcrypt_keys_init(void) { int ret; --=20 2.47.1