From: Darrick J. Wong <darrick.wong@oracle.com>
Date: Sat, 10 Dec 2016 14:55:01 +0000 (-0500)
Subject: ext4: reject inodes with negative size
X-Git-Tag: v3.2.87~163
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8e905a3924e225f6037cfa3420e9cdfd880adb85;p=pandora-kernel.git

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>
[bwh: Backported to 3.2: use EIO instead of EFSCORRUPTED]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 093a741d965c..274c91b5e9f6 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3829,6 +3829,7 @@ 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;
 
 	inode = iget_locked(sb, ino);
@@ -3880,6 +3881,11 @@ 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 = -EIO;
+		goto bad_inode;
+	}
 	ei->i_disksize = inode->i_size;
 #ifdef CONFIG_QUOTA
 	ei->i_reserved_quota = 0;