Messages in this thread Patch in this message | | | From | Vivek Goyal <> | Subject | [PATCH 4/9] selinux: Implementation for inode_copy_up_xattr() hook | Date | Wed, 13 Jul 2016 10:44:50 -0400 |
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When a file is copied up in overlay, we have already created file on upper/ with right label and there is no need to copy up selinux label/xattr from lower file to upper file. In fact in case of context mount, we don't want to copy up label as newly created file got its label from context= option.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com> --- security/selinux/hooks.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index c82ee54..4fda548 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3290,6 +3290,21 @@ static int selinux_inode_copy_up(struct dentry *src, struct cred **new) return 0; } +static int selinux_inode_copy_up_xattr(const char *name) +{ + /* The copy_up hook above sets the initial context on an inode, but we + * don't then want to overwrite it by blindly copying all the lower + * xattrs up. Instead, we have to filter out SELinux-related xattrs. + */ + if (strcmp(name, XATTR_NAME_SELINUX) == 0) + return 1; /* Discard */ + /* + * Any other attribute apart from SELINUX is not claimed, supported + * by selinux. + */ + return -EOPNOTSUPP; +} + /* file security operations */ static int selinux_revalidate_file_permission(struct file *file, int mask) @@ -6077,6 +6092,7 @@ static struct security_hook_list selinux_hooks[] = { LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity), LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid), LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up), + LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr), LSM_HOOK_INIT(file_permission, selinux_file_permission), LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security), -- 2.7.4
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