fix breakage caused by d_find_alias() semantics change
"VFS: don't keep disconnected dentries on d_anon" had a non-trivial
side-effect - d_unhashed() now returns true for those dentries,
making d_find_alias() skip them altogether. For most of its callers
that's fine - we really want a connected alias there. However,
there is a codepath where we relied upon picking such aliases
if nothing else could be found - selinux delayed initialization
of contexts for inodes on already mounted filesystems used to
rely upon that.
Cc: stable@kernel.org # f1ee616214cb "VFS: don't keep disconnected dentries on d_anon"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 4cafe6a..398d165 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1568,8 +1568,15 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
/* Called from d_instantiate or d_splice_alias. */
dentry = dget(opt_dentry);
} else {
- /* Called from selinux_complete_init, try to find a dentry. */
+ /*
+ * Called from selinux_complete_init, try to find a dentry.
+ * Some filesystems really want a connected one, so try
+ * that first. We could split SECURITY_FS_USE_XATTR in
+ * two, depending upon that...
+ */
dentry = d_find_alias(inode);
+ if (!dentry)
+ dentry = d_find_any_alias(inode);
}
if (!dentry) {
/*
@@ -1674,14 +1681,19 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
if ((sbsec->flags & SE_SBGENFS) && !S_ISLNK(inode->i_mode)) {
/* We must have a dentry to determine the label on
* procfs inodes */
- if (opt_dentry)
+ if (opt_dentry) {
/* Called from d_instantiate or
* d_splice_alias. */
dentry = dget(opt_dentry);
- else
+ } else {
/* Called from selinux_complete_init, try to
- * find a dentry. */
+ * find a dentry. Some filesystems really want
+ * a connected one, so try that first.
+ */
dentry = d_find_alias(inode);
+ if (!dentry)
+ dentry = d_find_any_alias(inode);
+ }
/*
* This can be hit on boot when a file is accessed
* before the policy is loaded. When we load policy we
