ceph: fix xattr rbtree search

Fix xattr name comparison in rbtree search for strings that share a prefix.
The *name argument is null terminated, but the xattr name is not, so we
need to use strncmp, but that means adjusting for the case where name is
a prefix of xattr->name.

The corresponding case in __set_xattr() already handles this properly
(although in that case *name is also not null terminated).

Reported-by: Sergiy Kibrik <sakib@meta.ua>
Signed-off-by: Sage Weil <sage@newdream.net>

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 6e12a6b..8c9eba6 100644 (file)
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -219,6 +219,7 @@ static struct ceph_inode_xattr *__get_xattr(struct ceph_inode_info *ci,
        struct rb_node **p;
        struct rb_node *parent = NULL;
        struct ceph_inode_xattr *xattr = NULL;
+       int name_len = strlen(name);
        int c;
 
        p = &ci->i_xattrs.index.rb_node;
@@ -226,6 +227,8 @@ static struct ceph_inode_xattr *__get_xattr(struct ceph_inode_info *ci,
                parent = *p;
                xattr = rb_entry(parent, struct ceph_inode_xattr, node);
                c = strncmp(name, xattr->name, xattr->name_len);
+               if (c == 0 && name_len > xattr->name_len)
+                       c = 1;
                if (c < 0)
                        p = &(*p)->rb_left;
                else if (c > 0)