From patchwork Mon Dec 13 23:20:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Disseldorp X-Patchwork-Id: 12674831 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 78E31C433EF for ; Mon, 13 Dec 2021 23:27:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244154AbhLMX1u (ORCPT ); Mon, 13 Dec 2021 18:27:50 -0500 Received: from smtp-out2.suse.de ([195.135.220.29]:46226 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242103AbhLMX1s (ORCPT ); Mon, 13 Dec 2021 18:27:48 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 3DE0A1F3C6; Mon, 13 Dec 2021 23:27:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1639438067; h=from:from:reply-to: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=mDlw3+F/2XMD4uChHoYTT839HaCwSlUPxhDd/Rgnxpo=; b=TcemtsPrEEprKUEcJOdcVX8GhbsreAo9v8QDRhw+3p6jBHgR7Z+k0IkdIkwfyIHlXYkdio eOWl/WzYf8+OOPxyRpqXFPfgx+V+XuKrWJkYiU5738JYpE+nEQJOZrgNt6zIQHkgfnOB52 aeyBJGzHP59R+6+I7c05rsostFKoylQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1639438067; h=from:from:reply-to: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=mDlw3+F/2XMD4uChHoYTT839HaCwSlUPxhDd/Rgnxpo=; b=vCrOx8+8n1QopirrSKZG5j0TZZR5J02GlzgTT0h/tC6TTK2q9nZMBqBJdzZA5fm+MfMXWD TdcvnQwtNPizkqCg== Received: from echidna.suse.de (unknown [10.163.47.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 12807A3B87; Mon, 13 Dec 2021 23:27:47 +0000 (UTC) From: David Disseldorp To: linux-fsdevel@vger.kernel.org Cc: Martin Wilck , viro@zeniv.linux.org.uk, willy@infradead.org, David Disseldorp Subject: [PATCH v5 5/5] initramfs: support cpio extraction with file checksums Date: Tue, 14 Dec 2021 00:20:08 +0100 Message-Id: <20211213232007.26851-6-ddiss@suse.de> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211213232007.26851-1-ddiss@suse.de> References: <20211213232007.26851-1-ddiss@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add support for the extraction of crc-enabled "070702" cpio archives, as specified in Documentation/driver-api/early-userspace/buffer-format.rst. Fail extraction if the calculated file data checksum doesn't match the value carried in the header. Suggested-by: Matthew Wilcox (Oracle) Signed-off-by: David Disseldorp --- init/initramfs.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-) diff --git a/init/initramfs.c b/init/initramfs.c index 5b4ca8ecadb5..ead3e2839f44 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -19,8 +19,11 @@ #include "initramfs_mtime.h" -static ssize_t __init xwrite(struct file *file, const char *p, size_t count, - loff_t *pos) +static __initdata bool csum_present; +static __initdata u32 io_csum; + +static ssize_t __init xwrite(struct file *file, const unsigned char *p, + size_t count, loff_t *pos) { ssize_t out = 0; @@ -35,6 +38,13 @@ static ssize_t __init xwrite(struct file *file, const char *p, size_t count, } else if (rv == 0) break; + if (csum_present) { + ssize_t i; + + for (i = 0; i < rv; i++) + io_csum += p[i]; + } + p += rv; out += rv; count -= rv; @@ -118,8 +128,6 @@ static void __init free_hash(void) } } -static __initdata time64_t mtime; - /* cpio header parsing */ static __initdata unsigned long ino, major, minor, nlink; @@ -128,15 +136,17 @@ static __initdata unsigned long body_len, name_len; static __initdata uid_t uid; static __initdata gid_t gid; static __initdata unsigned rdev; +static __initdata time64_t mtime; +static __initdata u32 hdr_csum; static void __init parse_header(char *s) { - unsigned long parsed[12]; + unsigned long parsed[13]; char buf[9]; int i; buf[8] = '\0'; - for (i = 0, s += 6; i < 12; i++, s += 8) { + for (i = 0, s += 6; i < 13; i++, s += 8) { memcpy(buf, s, 8); parsed[i] = simple_strtoul(buf, NULL, 16); } @@ -151,6 +161,7 @@ static void __init parse_header(char *s) minor = parsed[8]; rdev = new_encode_dev(MKDEV(parsed[9], parsed[10])); name_len = parsed[11]; + hdr_csum = parsed[12]; } /* FSM */ @@ -219,7 +230,11 @@ static int __init do_collect(void) static int __init do_header(void) { - if (memcmp(collected, "070701", 6)) { + if (!memcmp(collected, "070701", 6)) { + csum_present = false; + } else if (!memcmp(collected, "070702", 6)) { + csum_present = true; + } else { if (memcmp(collected, "070707", 6) == 0) error("incorrect cpio method used: use -H newc option"); else @@ -314,6 +329,7 @@ static int __init do_name(void) if (IS_ERR(wfile)) return 0; wfile_pos = 0; + io_csum = 0; vfs_fchown(wfile, uid, gid); vfs_fchmod(wfile, mode); @@ -346,6 +362,8 @@ static int __init do_copy(void) do_utime_path(&wfile->f_path, mtime); fput(wfile); + if (csum_present && io_csum != hdr_csum) + error("bad data checksum"); eat(body_len); state = SkipIt; return 0;