ext4: Check for an valid i_mode when reading the inode from disk

(cherry picked from commit 563bdd61fe4dbd6b58cf7eb06f8d8f14479ae1dc)

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 06fe69415d9cf5d13f7ee11a29265ea5a5c26d52..2bd8005e475879f4cc5cdc80676636677c39d355 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4129,7 +4129,8 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                        inode->i_op = &ext4_symlink_inode_operations;
                        ext4_set_aops(inode);
                }
-       } else {
+       } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
+             S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
                inode->i_op = &ext4_special_inode_operations;
                if (raw_inode->i_block[0])
                        init_special_inode(inode, inode->i_mode,
@@ -4137,6 +4138,13 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                else
                        init_special_inode(inode, inode->i_mode,
                           new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
+       } else {
+               brelse(bh);
+               ret = -EIO;
+               ext4_error(inode->i_sb, __func__,
+                          "bogus i_mode (%o) for inode=%lu",
+                          inode->i_mode, inode->i_ino);
+               goto bad_inode;
        }
        brelse (iloc.bh);
        ext4_set_inode_flags(inode);