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 EBA26C77B78 for ; Thu, 4 May 2023 20:06:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232778AbjEDUGs (ORCPT ); Thu, 4 May 2023 16:06:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51902 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232680AbjEDUE6 (ORCPT ); Thu, 4 May 2023 16:04:58 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F56818DF8; Thu, 4 May 2023 12:52:45 -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 B14436383F; Thu, 4 May 2023 19:51:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 53A9EC4339E; Thu, 4 May 2023 19:51:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1683229902; bh=kjDxpS1S+ouR3A6pmDzptiANECN9+w6b76/64cl+HkU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ExDheRZrBhxuSWyOWrEQkFjkCpuJmMh6PqI60tw7RsZ7LX/YnhWJwVF8Iu2KRG8cE gXZAqUk9JlMF6sclSkIdDhJbv0Q/AlcxIOtjIJHIcY+Dht0XE5juReshq6SNAjZ2ko YFWfo4hJAkMMdSn9uZHV/irbUqFhJV8DeWLBy2DXncxp6FZ7NiE15G1sLV36OvlE18 J/nARA2Ek1M/s86ldcAEIEdRIIh+iInRT7u4yNsvzosYtETAzH3tG/DY5wHLDL60Xu 8pkz0EsTb4R/kikcNbt2R5wZvxJpCxw76Zy+5Go+1QaLO/sM3cHxyyNF6J9eti0GEx FIwVboHAPTWSg== 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 4.19 03/13] ext2: Check block size validity during mount Date: Thu, 4 May 2023 15:51:20 -0400 Message-Id: <20230504195132.3808946-3-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230504195132.3808946-1-sashal@kernel.org> References: <20230504195132.3808946-1-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 00e759f051619..a203a5723e2c0 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 44a1f356aca29..3349ce85d27cb 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -978,6 +978,13 @@ 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 (sbi->s_mount_opt & EXT2_MOUNT_DAX) { -- 2.39.2