Don't reset ->total_link_count on nested calls of vfs_path_lookup()

we already zero it on outermost set_nameidata(), so initialization in
path_init() is pointless and wrong.  The same DoS exists on pre-4.2
kernels, but there a slightly different fix will be needed.

Cc: stable@vger.kernel.org # v4.2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/namei.c b/fs/namei.c
index d84d7c7515fc44415f11488f192e52ef3c9c9990..0c3974cd3ecd55670ccab51c596b0b141cbdd721 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1996,7 +1996,6 @@ static const char *path_init(struct nameidata *nd, unsigned flags)
        nd->last_type = LAST_ROOT; /* if there are only slashes... */
        nd->flags = flags | LOOKUP_JUMPED | LOOKUP_PARENT;
        nd->depth = 0;
-       nd->total_link_count = 0;
        if (flags & LOOKUP_ROOT) {
                struct dentry *root = nd->root.dentry;
                struct inode *inode = root->d_inode;