linux/fs/ext3/namei.h
Carlos Maiolino c3d59ad6ab ext3: ext3_bread usage audit
This is the ext3 version of the same patch applied to Ext4, where such goal is
to audit the usage of ext3_bread() due a possible misinterpretion of its return
value.

Focused on directory blocks, a NULL value returned from ext3_bread() means a
hole, which cannot exist into a directory inode. It can pass undetected after a
fix in an uninitialized error variable.

The (now) initialized variable into ext3_getblk() may lead to a zero'ed return
value of ext3_bread() to its callers, which can make the caller do not detect
the hole in the directory inode.

This patch creates a new wrapper function ext3_dir_bread() which checks for
holes properly, reports error, and returns EIO in that case.

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2012-10-09 23:21:42 +02:00

27 lines
570 B
C

/* linux/fs/ext3/namei.h
*
* Copyright (C) 2005 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*
*/
extern struct dentry *ext3_get_parent(struct dentry *child);
static inline struct buffer_head *ext3_dir_bread(handle_t *handle,
struct inode *inode,
int block, int create,
int *err)
{
struct buffer_head *bh;
bh = ext3_bread(handle, inode, block, create, err);
if (!bh && !(*err)) {
*err = -EIO;
ext3_error(inode->i_sb, __func__,
"Directory hole detected on inode %lu\n",
inode->i_ino);
return NULL;
}
return bh;
}