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 97AD9C7EE21 for ; Thu, 4 May 2023 20:04:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232439AbjEDUEO (ORCPT ); Thu, 4 May 2023 16:04:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232364AbjEDUDY (ORCPT ); Thu, 4 May 2023 16:03:24 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 087BC203D0; Thu, 4 May 2023 12:52:09 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 968BE63857; Thu, 4 May 2023 19:50:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 44F65C433A0; Thu, 4 May 2023 19:50:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1683229848; bh=3XUjR0Yuaid0YY9QqH2MkY2nc4b2+qzTNLaMT3WfB/c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qSlZdI3zn4/lokfBfQX2WadLTinJ/qjqW7R++icSaFTlCybKt+Zrcw0nrk4lMonzK X0t7DP5a3Vb6NFPuGB3yczVvgQMm+I+XjYPuTeFl89T6eV+7SVHiDTdrRbvneZEOC0 sFraHWdaoueHt3TG5isYt7gOlYo/mqE0+j7uy0FgiY3/d/7Pvuh1t1UpNOooO1Ul21 DDQkt9sHNqSKbGuQCYUIZhHq5AwEZCIPM2f1v2b9q73wow13VWYw2UJBsERAy2K/zX 8X4bKwkNy4L2xFNakGn8UoWvoCg1LzT9nycNqJmBDzxTlINeC4qB3XpbxcC4bACtMg 4FaI/ijPJQhIw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jan Kara , syzbot+4fec412f59eba8c01b77@syzkaller.appspotmail.com, Sasha Levin , jack@suse.com, linux-ext4@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 02/18] ext2: Check block size validity during mount Date: Thu, 4 May 2023 15:50:24 -0400 Message-Id: <20230504195042.3808716-2-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230504195042.3808716-1-sashal@kernel.org> References: <20230504195042.3808716-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jan Kara [ Upstream commit 62aeb94433fcec80241754b70d0d1836d5926b0a ] Check that log of block size stored in the superblock has sensible value. Otherwise the shift computing the block size can overflow leading to undefined behavior. Reported-by: syzbot+4fec412f59eba8c01b77@syzkaller.appspotmail.com Signed-off-by: Jan Kara Signed-off-by: Sasha Levin --- fs/ext2/ext2.h | 1 + fs/ext2/super.c | 7 +++++++ 2 files changed, 8 insertions(+) diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h index 10ab238de9a65..a89b43d759052 100644 --- a/fs/ext2/ext2.h +++ b/fs/ext2/ext2.h @@ -177,6 +177,7 @@ static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb) #define EXT2_MIN_BLOCK_SIZE 1024 #define EXT2_MAX_BLOCK_SIZE 4096 #define EXT2_MIN_BLOCK_LOG_SIZE 10 +#define EXT2_MAX_BLOCK_LOG_SIZE 16 #define EXT2_BLOCK_SIZE(s) ((s)->s_blocksize) #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (__u32)) #define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_blocksize_bits) diff --git a/fs/ext2/super.c b/fs/ext2/super.c index 644c83c115bc2..6e8e47871fa26 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -967,6 +967,13 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) goto failed_mount; } + if (le32_to_cpu(es->s_log_block_size) > + (EXT2_MAX_BLOCK_LOG_SIZE - BLOCK_SIZE_BITS)) { + ext2_msg(sb, KERN_ERR, + "Invalid log block size: %u", + le32_to_cpu(es->s_log_block_size)); + goto failed_mount; + } blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); if (test_opt(sb, DAX)) { -- 2.39.2