>From efcee80eb78816a4d495224ffc624adf04217044 Mon Sep 17 00:00:00 2001 From: Vegard Nossum Date: Fri, 1 Jul 2016 15:03:39 +0200 Subject: [PATCH] ext4: validate number of base meta clusters in group --- fs/ext4/balloc.c | 4 +--- fs/ext4/ext4.h | 2 ++ fs/ext4/super.c | 10 ++++++++++ 3 files changed, 13 insertions(+), 3 deletions(-) diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 3020fd7..ec03f01 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -22,8 +22,6 @@ #include -static unsigned ext4_num_base_meta_clusters(struct super_block *sb, - ext4_group_t block_group); /* * balloc.c contains the blocks allocation and deallocation routines */ @@ -817,7 +815,7 @@ unsigned long ext4_bg_num_gdb(struct super_block *sb, ext4_group_t group) * This function returns the number of file system metadata clusters at * the beginning of a block group, including the reserved gdt blocks. */ -static unsigned ext4_num_base_meta_clusters(struct super_block *sb, +unsigned ext4_num_base_meta_clusters(struct super_block *sb, ext4_group_t block_group) { struct ext4_sb_info *sbi = EXT4_SB(sb); diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index b84aa1ca..e492b0b 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2270,6 +2270,8 @@ extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb, extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group); extern unsigned long ext4_bg_num_gdb(struct super_block *sb, ext4_group_t group); +extern unsigned ext4_num_base_meta_clusters(struct super_block *sb, + ext4_group_t block_group); extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode, ext4_fsblk_t goal, unsigned int flags, diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 563555e..b5a9d28 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3641,6 +3641,16 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) goto failed_mount; } sbi->s_groups_count = blocks_count; + + for (i = 0; i < sbi->s_groups_count; ++i) { + int bit_max = ext4_num_base_meta_clusters(sb, i); + if ((bit_max >> 3) >= sb->s_blocksize) { + ext4_msg(sb, KERN_WARNING, "meta cluster base for " + "group %u exceeds block size", i); + goto failed_mount; + } + } + sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count, (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb))); db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) / -- 1.9.1