ext4: reject inodes with negative size

commit 7e6e1ef48fc02f3ac5d0edecbb0c6087cd758d58 upstream.

Don't load an inode with a negative size; this causes integer overflow
problems in the VFS.

[ Added EXT4_ERROR_INODE() to mark file system as corrupted. -TYT]

Fixes: a48380f769df (ext4: rename i_dir_acl to i_size_high)
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 9c064727ed62..33a509c876ee 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4434,6 +4434,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
         struct inode *inode;
         journal_t *journal = EXT4_SB(sb)->s_journal;
         long ret;
+        loff_t size;
         int block;
         uid_t i_uid;
         gid_t i_gid;
@@ -4534,6 +4535,11 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                 ei->i_file_acl |=
                         ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
         inode->i_size = ext4_isize(raw_inode);
+        if ((size = i_size_read(inode)) < 0) {
+                EXT4_ERROR_INODE(inode, "bad i_size value: %lld", size);
+                ret = -EFSCORRUPTED;
+                goto bad_inode;
+        }
         ei->i_disksize = inode->i_size;
 #ifdef CONFIG_QUOTA
         ei->i_reserved_quota = 0;