ext4: add ext4_iget_normal() which is to be used for dir tree lookups
commit f4bb2981024fc91b23b4d09a8817c415396dbabb upstream.
If there is a corrupted file system which has directory entries that
point at reserved, metadata inodes, prohibit them from being used by
treating them the same way we treat Boot Loader inodes --- that is,
mark them to be bad inodes. This prohibits them from being opened,
deleted, or modified via chmod, chown, utimes, etc.
In particular, this prevents a corrupted file system which has a
directory entry which points at the journal inode from being deleted
and its blocks released, after which point Much Hilarity Ensues.
Reported-by: Sami Liedes <sami.liedes@iki.fi>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Zefan Li <lizefan@huawei.com>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 521ba9d..b9cdb6d 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1891,6 +1891,7 @@
struct buffer_head *bh_result, int create);
extern struct inode *ext4_iget(struct super_block *, unsigned long);
+extern struct inode *ext4_iget_normal(struct super_block *, unsigned long);
extern int ext4_write_inode(struct inode *, struct writeback_control *);
extern int ext4_setattr(struct dentry *, struct iattr *);
extern int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index b9c3995..c3598f1 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3838,6 +3838,13 @@
return ERR_PTR(ret);
}
+struct inode *ext4_iget_normal(struct super_block *sb, unsigned long ino)
+{
+ if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
+ return ERR_PTR(-EIO);
+ return ext4_iget(sb, ino);
+}
+
static int ext4_inode_blocks_set(handle_t *handle,
struct ext4_inode *raw_inode,
struct ext4_inode_info *ei)
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 11566d7..c6dd936 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1051,7 +1051,7 @@
dentry->d_name.name);
return ERR_PTR(-EIO);
}
- inode = ext4_iget(dir->i_sb, ino);
+ inode = ext4_iget_normal(dir->i_sb, ino);
if (inode == ERR_PTR(-ESTALE)) {
EXT4_ERROR_INODE(dir,
"deleted inode referenced: %u",
@@ -1087,7 +1087,7 @@
return ERR_PTR(-EIO);
}
- return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
+ return d_obtain_alias(ext4_iget_normal(child->d_inode->i_sb, ino));
}
#define S_SHIFT 12
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 481f924..92ea560 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1041,7 +1041,7 @@
* Currently we don't know the generation for parent directory, so
* a generation of 0 means "accept any"
*/
- inode = ext4_iget(sb, ino);
+ inode = ext4_iget_normal(sb, ino);
if (IS_ERR(inode))
return ERR_CAST(inode);
if (generation && inode->i_generation != generation) {