[patch 096/114] ext4: Fix NULL dereference in ext4_ext_migrate()s error handling

Greg KH
2009-03-14T01:56:48Z

[-- Attachment #1: ext4-fix-null-dereference-in-ext4_ext_migrate-s-error-handling.patch --]
[-- Type: text/plain, Size: 1299 bytes --]

2.6.28-stable review patch. If anyone has any objections, please let us know.

------------------

From: Dan Carpenter <error27@gmail.com>

(cherry picked from commit 090542641de833c6f756895fc2f139f046e298f9)

This was found through a code checker (http://repo.or.cz/w/smatch.git/).
It looks like you might be able to trigger the error by trying to migrate
a readonly file system.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
fs/ext4/migrate.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -480,7 +480,7 @@ int ext4_ext_migrate(struct inode *inode
+ 1);
if (IS_ERR(handle)) {
retval = PTR_ERR(handle);
- goto err_out;
+ return retval;
}
tmp_inode = ext4_new_inode(handle,
inode->i_sb->s_root->d_inode,
@@ -488,8 +488,7 @@ int ext4_ext_migrate(struct inode *inode
if (IS_ERR(tmp_inode)) {
retval = -ENOMEM;
ext4_journal_stop(handle);
- tmp_inode = NULL;
- goto err_out;
+ return retval;
}
i_size_write(tmp_inode, i_size_read(inode));
/*
@@ -617,8 +616,7 @@ err_out:

ext4_journal_stop(handle);

- if (tmp_inode)
- iput(tmp_inode);
+ iput(tmp_inode);

return retval;
}