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>

1 files changed, 10 insertions, 0 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 25811507d2b0..cd0399db0ef1 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4345,6 +4345,16 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                         (__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;