ext4: protect journal inode's blocks using block_validity

Add the blocks which belong to the journal inode to block_validity's
system zone so attempts to deallocate or overwrite the journal due a
corrupted file system where the journal blocks are also claimed by
another inode.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202879
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
This commit is contained in:
Theodore Ts'o 2019-04-09 23:37:08 -04:00
parent 1e83bc8156
commit 345c0dbf3a
2 changed files with 52 additions and 0 deletions

View File

@ -137,6 +137,48 @@ static void debug_print_tree(struct ext4_sb_info *sbi)
printk(KERN_CONT "\n");
}
static int ext4_protect_reserved_inode(struct super_block *sb, u32 ino)
{
struct inode *inode;
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_map_blocks map;
u32 i = 0, err = 0, num, n;
if ((ino < EXT4_ROOT_INO) ||
(ino > le32_to_cpu(sbi->s_es->s_inodes_count)))
return -EINVAL;
inode = ext4_iget(sb, ino, EXT4_IGET_SPECIAL);
if (IS_ERR(inode))
return PTR_ERR(inode);
num = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
while (i < num) {
map.m_lblk = i;
map.m_len = num - i;
n = ext4_map_blocks(NULL, inode, &map, 0);
if (n < 0) {
err = n;
break;
}
if (n == 0) {
i++;
} else {
if (!ext4_data_block_valid(sbi, map.m_pblk, n)) {
ext4_error(sb, "blocks %llu-%llu from inode %u "
"overlap system zone", map.m_pblk,
map.m_pblk + map.m_len - 1, ino);
err = -EFSCORRUPTED;
break;
}
err = add_system_zone(sbi, map.m_pblk, n);
if (err < 0)
break;
i += n;
}
}
iput(inode);
return err;
}
int ext4_setup_system_zone(struct super_block *sb)
{
ext4_group_t ngroups = ext4_get_groups_count(sb);
@ -171,6 +213,12 @@ int ext4_setup_system_zone(struct super_block *sb)
if (ret)
return ret;
}
if (ext4_has_feature_journal(sb) && sbi->s_es->s_journal_inum) {
ret = ext4_protect_reserved_inode(sb,
le32_to_cpu(sbi->s_es->s_journal_inum));
if (ret)
return ret;
}
if (test_opt(sb, DEBUG))
debug_print_tree(sbi);

View File

@ -399,6 +399,10 @@ static int __check_block_validity(struct inode *inode, const char *func,
unsigned int line,
struct ext4_map_blocks *map)
{
if (ext4_has_feature_journal(inode->i_sb) &&
(inode->i_ino ==
le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_journal_inum)))
return 0;
if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk,
map->m_len)) {
ext4_error_inode(inode, func, line, map->m_pblk,