From patchwork Tue Jul 26 05:22:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 1660557 X-Patchwork-Delegate: trini@ti.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=suse.com header.i=@suse.com header.a=rsa-sha256 header.s=susede1 header.b=fLk6TudH; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.denx.de (client-ip=85.214.62.61; helo=phobos.denx.de; envelope-from=u-boot-bounces@lists.denx.de; receiver=) Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4LsQL61bCsz9sB4 for ; Tue, 26 Jul 2022 15:23:26 +1000 (AEST) Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id AE02D8415B; Tue, 26 Jul 2022 07:22:51 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de Authentication-Results: phobos.denx.de; dkim=pass (1024-bit key; unprotected) header.d=suse.com header.i=@suse.com header.b="fLk6TudH"; dkim-atps=neutral Received: by phobos.denx.de (Postfix, from userid 109) id BCC9F84106; Tue, 26 Jul 2022 07:22:48 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on phobos.denx.de X-Spam-Level: X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.2 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by phobos.denx.de (Postfix) with ESMTPS id 95A69840AD for ; Tue, 26 Jul 2022 07:22:46 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=wqu@suse.com Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 6155A34B51; Tue, 26 Jul 2022 05:22:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1658812966; 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=ZLc970s389r/cBG+Tk6HiktCaenz0z1leWM65Yqb4cM=; b=fLk6TudHoT+JLEGOrxAn580XFm1vaQpfaOfETyDKGygy1FARe3SnVNwWPpMedlX0ATu13j qg25x0xklR+28ZfBMY7mhrx3VsiBwFA0rdEyJDYI0thRXek11fb/yLECTXgjgnfA6v9aHq SSHuPnitQocz5xePUUJaiiO27GeJE5Q= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 6788913A12; Tue, 26 Jul 2022 05:22:44 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id eDLEDiR632IFOwAAMHmgww (envelope-from ); Tue, 26 Jul 2022 05:22:44 +0000 From: Qu Wenruo To: u-boot@lists.denx.de Cc: marek.behun@nic.cz, linux-btrfs@vger.kernel.org, jnhuang95@gmail.com, linux-erofs@lists.ozlabs.org, trini@konsulko.com, joaomarcos.costa@bootlin.com, thomas.petazzoni@bootlin.com, miquel.raynal@bootlin.com Subject: [PATCH v2 3/8] fs: btrfs: fix a crash if specified range is beyond file size Date: Tue, 26 Jul 2022 13:22:11 +0800 Message-Id: X-Mailer: git-send-email 2.37.0 In-Reply-To: References: MIME-Version: 1.0 X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.39 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" X-Virus-Scanned: clamav-milter 0.103.6 at phobos.denx.de X-Virus-Status: Clean [BUG] When try to read a range beyond file size, btrfs driver will cause crash/segfault: => load host 0 $kernel_addr_r 5k_file 0 0x2000 SEGFAULT [CAUSE] In btrfs_read(), if @len is 0, we will truncated it to file end, but if file end is beyond our file size, this truncation will underflow @len, making it -3K in this case. And later that @len is used to memzero the output buffer, resulting above crash. [FIX] Just error out if @offset is already beyond our file size. Now it will fail properly with correct error message: => load host 0 $kernel_addr_r 5m_origin 0 0x2000 BTRFS: Read range beyond file size, offset 8192 file size 5120 Failed to load '5m_origin' Signed-off-by: Qu Wenruo --- fs/btrfs/btrfs.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/btrfs/btrfs.c b/fs/btrfs/btrfs.c index 9145727058d4..bf9e1f2f17cf 100644 --- a/fs/btrfs/btrfs.c +++ b/fs/btrfs/btrfs.c @@ -252,6 +252,12 @@ int btrfs_read(const char *file, void *buf, loff_t offset, loff_t len, return ret; } + if (offset >= real_size) { + error("Read range beyond file size, offset %llu file size %llu", + offset, real_size); + return -EINVAL; + } + /* * If the length is 0 (meaning read the whole file) or the range is * beyond file size, truncate it to the end of the file.