From ec882da5cda911e799b8a5ede94d099fdc0c656b Mon Sep 17 00:00:00 2001 From: Ondrej Mosnacek Date: Fri, 22 Feb 2019 15:57:17 +0100 Subject: [PATCH] selinux: implement the kernfs_init_security hook The hook applies the same logic as selinux_determine_inode_label(), with the exception of the super_block handling, which will be enforced on the actual inodes later by other hooks. Signed-off-by: Ondrej Mosnacek [PM: minor merge fixes] Signed-off-by: Paul Moore --- security/selinux/hooks.c | 66 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 085409b36794..ab4b049daf17 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -89,6 +89,8 @@ #include #include #include +#include +#include /* for hashlen_string() */ #include #include "avc.h" @@ -3382,6 +3384,68 @@ static int selinux_inode_copy_up_xattr(const char *name) return -EOPNOTSUPP; } +/* kernfs node operations */ + +int selinux_kernfs_init_security(struct kernfs_node *kn_dir, + struct kernfs_node *kn) +{ + const struct task_security_struct *tsec = current_security(); + u32 parent_sid, newsid, clen; + int rc; + char *context; + + rc = kernfs_security_xattr_get(kn_dir, XATTR_SELINUX_SUFFIX, NULL, 0); + if (rc == -ENODATA) + return 0; + else if (rc < 0) + return rc; + + clen = (u32)rc; + context = kmalloc(clen, GFP_KERNEL); + if (!context) + return -ENOMEM; + + rc = kernfs_security_xattr_get(kn_dir, XATTR_SELINUX_SUFFIX, context, + clen); + if (rc < 0) { + kfree(context); + return rc; + } + + rc = security_context_to_sid(&selinux_state, context, clen, &parent_sid, + GFP_KERNEL); + kfree(context); + if (rc) + return rc; + + if (tsec->create_sid) { + newsid = tsec->create_sid; + } else { + u16 secclass = inode_mode_to_security_class(kn->mode); + struct qstr q; + + q.name = kn->name; + q.hash_len = hashlen_string(kn_dir, kn->name); + + rc = security_transition_sid(&selinux_state, tsec->sid, + parent_sid, secclass, &q, + &newsid); + if (rc) + return rc; + } + + rc = security_sid_to_context_force(&selinux_state, newsid, + &context, &clen); + if (rc) + return rc; + + rc = kernfs_security_xattr_set(kn, XATTR_SELINUX_SUFFIX, context, clen, + XATTR_CREATE); + kfree(context); + return rc; +} + + /* file security operations */ static int selinux_revalidate_file_permission(struct file *file, int mask) @@ -6730,6 +6794,8 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { 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(kernfs_init_security, selinux_kernfs_init_security), + LSM_HOOK_INIT(file_permission, selinux_file_permission), LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security), LSM_HOOK_INIT(file_ioctl, selinux_file_ioctl), -- 2.30.2