Commit ecaff756 authored by NeilBrown's avatar NeilBrown Committed by Linus Torvalds

[PATCH] knfsd: Have ext2 reject file handles with bad inode numbers early

This prevents bad inode numbers from triggering errors in ext2_get_inode.

[akpm@osdl.org: speedup, cleanup]
Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 55ebcc38
......@@ -251,6 +251,44 @@ static struct super_operations ext2_sops = {
#endif
};
static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp)
{
__u32 *objp = vobjp;
unsigned long ino = objp[0];
__u32 generation = objp[1];
struct inode *inode;
struct dentry *result;
if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
return ERR_PTR(-ESTALE);
if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
return ERR_PTR(-ESTALE);
/* iget isn't really right if the inode is currently unallocated!!
* ext2_read_inode currently does appropriate checks, but
* it might be "neater" to call ext2_get_inode first and check
* if the inode is valid.....
*/
inode = iget(sb, ino);
if (inode == NULL)
return ERR_PTR(-ENOMEM);
if (is_bad_inode(inode) ||
(generation && inode->i_generation != generation)) {
/* we didn't find the right inode.. */
iput(inode);
return ERR_PTR(-ESTALE);
}
/* now to find a dentry.
* If possible, get a well-connected one
*/
result = d_alloc_anon(inode);
if (!result) {
iput(inode);
return ERR_PTR(-ENOMEM);
}
return result;
}
/* Yes, most of these are left as NULL!!
* A NULL value implies the default, which works with ext2-like file
* systems, but can be improved upon.
......@@ -258,6 +296,7 @@ static struct super_operations ext2_sops = {
*/
static struct export_operations ext2_export_ops = {
.get_parent = ext2_get_parent,
.get_dentry = ext2_get_dentry,
};
static unsigned long get_sb_block(void **data)
......
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