Return-Path: Received: from szxga05-in.huawei.com ([45.249.212.191]:17128 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725783AbfAJF2R (ORCPT ); Thu, 10 Jan 2019 00:28:17 -0500 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 8AF00AC3A152A8DEFD7E for ; Thu, 10 Jan 2019 13:28:15 +0800 (CST) From: yangerkun To: CC: , , , Subject: [PATCH] ext2: add check for blocksize in ext2_fill_super Date: Thu, 10 Jan 2019 13:31:45 +0800 Message-ID: <20190110053145.138518-1-yangerkun@huawei.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-ext4-owner@vger.kernel.org List-ID: While mkfs with '-b 65536' and then mount this fs with arm 64KB page size, function mount_fs will trigger WARNING because that ext2_max_size will return value less than 0. Also, we cannot write any file in this fs since the sb->s_maxbytes is less than 0. Avoid this by check blocksize in ext2_fill_super like ext4_fill_super. Signed-off-by: yangerkun --- fs/ext2/ext2.h | 1 + fs/ext2/super.c | 15 +++++++++++++++ 2 files changed, 16 insertions(+) diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h index e770cd1..ba95316 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 12 #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 73b2d52..029945e 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -960,6 +960,21 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) } blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); + if (blocksize < EXT2_MIN_BLOCK_SIZE || + blocksize > EXT2_MAX_BLOCK_SIZE) { + ext2_msg(sb, KERN_ERR, + "Unsupported filesystem blocksize %d (%d log_block_size)", + blocksize, le32_to_cpu(es->s_log_block_size)); + goto failed_mount; + } + + if (le32_to_cpu(es->s_log_block_size) > + (EXT2_MAX_BLOCK_LOG_SIZE - EXT2_MIN_BLOCK_LOG_SIZE)) { + ext2_msg(sb, KERN_ERR, + "Invalid log block size: %u", + le32_to_cpu(es->s_log_block_size)); + goto failed_mount; + } if (sbi->s_mount_opt & EXT2_MOUNT_DAX) { if (!bdev_dax_supported(sb->s_bdev, blocksize)) { -- 2.9.5