ext4: Validate extent details only when read from the disk
Make sure we validate extent details only when read from the disk.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Thiemo Nagel <thiemo.nagel@ph.tum.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/ext4_extents.h b/fs/ext4/ext4_extents.h
index 18cb67b..f0c3ec85 100644
--- a/fs/ext4/ext4_extents.h
+++ b/fs/ext4/ext4_extents.h
@@ -241,5 +241,6 @@
extern int ext4_ext_search_right(struct inode *, struct ext4_ext_path *,
ext4_lblk_t *, ext4_fsblk_t *);
extern void ext4_ext_drop_refs(struct ext4_ext_path *);
+extern int ext4_ext_check_inode(struct inode *inode);
#endif /* _EXT4_EXTENTS */
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index ee40b7c..ac77d8b 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -429,6 +429,11 @@
#define ext4_ext_check(inode, eh, depth) \
__ext4_ext_check(__func__, inode, eh, depth)
+int ext4_ext_check_inode(struct inode *inode)
+{
+ return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
+}
+
#ifdef EXT_DEBUG
static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
{
@@ -631,9 +636,6 @@
eh = ext_inode_hdr(inode);
depth = ext_depth(inode);
- if (ext4_ext_check(inode, eh, depth))
- return ERR_PTR(-EIO);
-
/* account possible depth increase */
if (!path) {
@@ -649,6 +651,8 @@
i = depth;
/* walk through the tree */
while (i) {
+ int need_to_validate = 0;
+
ext_debug("depth %d: num %d, max %d\n",
ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
@@ -657,10 +661,17 @@
path[ppos].p_depth = i;
path[ppos].p_ext = NULL;
- bh = sb_bread(inode->i_sb, path[ppos].p_block);
- if (!bh)
+ bh = sb_getblk(inode->i_sb, path[ppos].p_block);
+ if (unlikely(!bh))
goto err;
-
+ if (!bh_uptodate_or_lock(bh)) {
+ if (bh_submit_read(bh) < 0) {
+ put_bh(bh);
+ goto err;
+ }
+ /* validate the extent entries */
+ need_to_validate = 1;
+ }
eh = ext_block_hdr(bh);
ppos++;
BUG_ON(ppos > depth);
@@ -668,7 +679,7 @@
path[ppos].p_hdr = eh;
i--;
- if (ext4_ext_check(inode, eh, i))
+ if (need_to_validate && ext4_ext_check(inode, eh, i))
goto err;
}
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 2581150..cd0399d 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4345,6 +4345,16 @@
(__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
}
+ if (ei->i_flags & EXT4_EXTENTS_FL) {
+ /* Validate extent which is part of inode */
+ ret = ext4_ext_check_inode(inode);
+ if (ret) {
+ brelse(bh);
+ goto bad_inode;
+ }
+
+ }
+
if (S_ISREG(inode->i_mode)) {
inode->i_op = &ext4_file_inode_operations;
inode->i_fop = &ext4_file_operations;