From b127125d9db23e4856156a7c909a3c8e18b69f99 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 25 Apr 2018 10:28:38 -0400 Subject: 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 --- security/selinux/hooks.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) (limited to 'security/selinux') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 4cafe6a19167..398d165f884e 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 -- cgit v1.2.3