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authorTheodore Ts'o <tytso@mit.edu>2014-10-05 22:56:00 -0400
committerBen Hutchings <ben@decadent.org.uk>2014-12-14 16:23:47 +0000
commitcb3a8d202d5a53def600a510f873a7cc7bc41150 (patch)
treecbe3fdf587e503d8f16d9dd44df79b349b1f3de2 /fs
parenta9fa6b67b710a73cd701d15ca101e682ff4b66c3 (diff)
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: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'fs')
-rw-r--r--fs/ext4/ext4.h1
-rw-r--r--fs/ext4/inode.c7
-rw-r--r--fs/ext4/namei.c4
-rw-r--r--fs/ext4/super.c2
4 files changed, 11 insertions, 3 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 40f4d062708f..6858d9db4757 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1874,6 +1874,7 @@ int ext4_get_block(struct inode *inode, sector_t iblock,
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 c343cdc9dc15..74c34c2115e0 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3958,6 +3958,13 @@ bad_inode:
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 c4bf1ad616b6..7ed4b0364b5b 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1040,7 +1040,7 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, stru
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",
@@ -1074,7 +1074,7 @@ struct dentry *ext4_get_parent(struct dentry *child)
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 f897cb81c262..422be11b229b 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1185,7 +1185,7 @@ static struct inode *ext4_nfs_get_inode(struct super_block *sb,
* 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) {