Merge tag 'selinux-pr-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull selinux updates from Paul Moore:

 - Add support for measuring the SELinux state and policy capabilities
   using IMA.

 - A handful of SELinux/NFS patches to compare the SELinux state of one
   mount with a set of mount options. Olga goes into more detail in the
   patch descriptions, but this is important as it allows more
   flexibility when using NFS and SELinux context mounts.

 - Properly differentiate between the subjective and objective LSM
   credentials; including support for the SELinux and Smack. My clumsy
   attempt at a proper fix for AppArmor didn't quite pass muster so John
   is working on a proper AppArmor patch, in the meantime this set of
   patches shouldn't change the behavior of AppArmor in any way. This
   change explains the bulk of the diffstat beyond security/.

 - Fix a problem where we were not properly terminating the permission
   list for two SELinux object classes.

* tag 'selinux-pr-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: add proper NULL termination to the secclass_map permissions
  smack: differentiate between subjective and objective task credentials
  selinux: clarify task subjective and objective credentials
  lsm: separate security_task_getsecid() into subjective and objective variants
  nfs: account for selinux security context when deciding to share superblock
  nfs: remove unneeded null check in nfs_fill_super()
  lsm,selinux: add new hook to compare new mount to an existing mount
  selinux: fix misspellings using codespell tool
  selinux: fix misspellings using codespell tool
  selinux: measure state and policy capabilities
  selinux: Allow context mounts for unpriviliged overlayfs

1 files changed, 27 insertions, 12 deletions

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 12a45e61c1a5..cd14bec4ad80 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -159,7 +159,7 @@ static int smk_bu_current(char *note, struct smack_known *oskp,
 static int smk_bu_task(struct task_struct *otp, int mode, int rc)
 {
 	struct task_smack *tsp = smack_cred(current_cred());
-	struct smack_known *smk_task = smk_of_task_struct(otp);
+	struct smack_known *smk_task = smk_of_task_struct_obj(otp);
 	char acc[SMK_NUM_ACCESS_TYPE + 1];
 
 	if (rc <= 0)
@@ -479,7 +479,7 @@ static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
 {
 	struct smack_known *skp;
 
-	skp = smk_of_task_struct(ctp);
+	skp = smk_of_task_struct_obj(ctp);
 
 	return smk_ptrace_rule_check(current, skp, mode, __func__);
 }
@@ -2033,7 +2033,7 @@ static int smk_curacc_on_task(struct task_struct *p, int access,
 				const char *caller)
 {
 	struct smk_audit_info ad;
-	struct smack_known *skp = smk_of_task_struct(p);
+	struct smack_known *skp = smk_of_task_struct_subj(p);
 	int rc;
 
 	smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
@@ -2078,15 +2078,29 @@ static int smack_task_getsid(struct task_struct *p)
 }
 
 /**
- * smack_task_getsecid - get the secid of the task
- * @p: the object task
+ * smack_task_getsecid_subj - get the subjective secid of the task
+ * @p: the task
  * @secid: where to put the result
  *
- * Sets the secid to contain a u32 version of the smack label.
+ * Sets the secid to contain a u32 version of the task's subjective smack label.
+ */
+static void smack_task_getsecid_subj(struct task_struct *p, u32 *secid)
+{
+	struct smack_known *skp = smk_of_task_struct_subj(p);
+
+	*secid = skp->smk_secid;
+}
+
+/**
+ * smack_task_getsecid_obj - get the objective secid of the task
+ * @p: the task
+ * @secid: where to put the result
+ *
+ * Sets the secid to contain a u32 version of the task's objective smack label.
  */
-static void smack_task_getsecid(struct task_struct *p, u32 *secid)
+static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid)
 {
-	struct smack_known *skp = smk_of_task_struct(p);
+	struct smack_known *skp = smk_of_task_struct_obj(p);
 
 	*secid = skp->smk_secid;
 }
@@ -2174,7 +2188,7 @@ static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info,
 {
 	struct smk_audit_info ad;
 	struct smack_known *skp;
-	struct smack_known *tkp = smk_of_task_struct(p);
+	struct smack_known *tkp = smk_of_task_struct_obj(p);
 	int rc;
 
 	if (!sig)
@@ -2212,7 +2226,7 @@ static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info,
 static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
 {
 	struct inode_smack *isp = smack_inode(inode);
-	struct smack_known *skp = smk_of_task_struct(p);
+	struct smack_known *skp = smk_of_task_struct_obj(p);
 
 	isp->smk_inode = skp;
 	isp->smk_flags |= SMK_INODE_INSTANT;
@@ -3483,7 +3497,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
  */
 static int smack_getprocattr(struct task_struct *p, char *name, char **value)
 {
-	struct smack_known *skp = smk_of_task_struct(p);
+	struct smack_known *skp = smk_of_task_struct_subj(p);
 	char *cp;
 	int slen;
 
@@ -4759,7 +4773,8 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(task_setpgid, smack_task_setpgid),
 	LSM_HOOK_INIT(task_getpgid, smack_task_getpgid),
 	LSM_HOOK_INIT(task_getsid, smack_task_getsid),
-	LSM_HOOK_INIT(task_getsecid, smack_task_getsecid),
+	LSM_HOOK_INIT(task_getsecid_subj, smack_task_getsecid_subj),
+	LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj),
 	LSM_HOOK_INIT(task_setnice, smack_task_setnice),
 	LSM_HOOK_INIT(task_setioprio, smack_task_setioprio),
 	LSM_HOOK_INIT(task_getioprio, smack_task_getioprio),