4 files changed, 41 insertions, 39 deletions

diff --git a/kernel/cred.c b/kernel/cred.c
index 7a0d8066988..eddc5e2e958 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -49,6 +49,14 @@ struct cred init_cred = {
         .subscribers            = ATOMIC_INIT(2),
         .magic                  = CRED_MAGIC,
 #endif
+        .uid                    = GLOBAL_ROOT_UID,
+        .gid                    = GLOBAL_ROOT_GID,
+        .suid                   = GLOBAL_ROOT_UID,
+        .sgid                   = GLOBAL_ROOT_GID,
+        .euid                   = GLOBAL_ROOT_UID,
+        .egid                   = GLOBAL_ROOT_GID,
+        .fsuid                  = GLOBAL_ROOT_UID,
+        .fsgid                  = GLOBAL_ROOT_GID,
         .securebits             = SECUREBITS_DEFAULT,
         .cap_inheritable        = CAP_EMPTY_SET,
         .cap_permitted          = CAP_FULL_SET,
@@ -488,10 +496,10 @@ int commit_creds(struct cred *new)
         get_cred(new); /* we will require a ref for the subj creds too */
 
         /* dumpability changes */
-        if (old->euid != new->euid ||
-            old->egid != new->egid ||
-            old->fsuid != new->fsuid ||
-            old->fsgid != new->fsgid ||
+        if (!uid_eq(old->euid, new->euid) ||
+            !gid_eq(old->egid, new->egid) ||
+            !uid_eq(old->fsuid, new->fsuid) ||
+            !gid_eq(old->fsgid, new->fsgid) ||
             !cap_issubset(new->cap_permitted, old->cap_permitted)) {
                 if (task->mm)
                         set_dumpable(task->mm, suid_dumpable);
@@ -500,9 +508,9 @@ int commit_creds(struct cred *new)
         }
 
         /* alter the thread keyring */
-        if (new->fsuid != old->fsuid)
+        if (!uid_eq(new->fsuid, old->fsuid))
                 key_fsuid_changed(task);
-        if (new->fsgid != old->fsgid)
+        if (!gid_eq(new->fsgid, old->fsgid))
                 key_fsgid_changed(task);
 
         /* do it
@@ -519,16 +527,16 @@ int commit_creds(struct cred *new)
         alter_cred_subscribers(old, -2);
 
         /* send notifications */
-        if (new->uid   != old->uid  ||
-            new->euid  != old->euid ||
-            new->suid  != old->suid ||
-            new->fsuid != old->fsuid)
+        if (!uid_eq(new->uid,   old->uid)  ||
+            !uid_eq(new->euid,  old->euid) ||
+            !uid_eq(new->suid,  old->suid) ||
+            !uid_eq(new->fsuid, old->fsuid))
                 proc_id_connector(task, PROC_EVENT_UID);
 
-        if (new->gid   != old->gid  ||
-            new->egid  != old->egid ||
-            new->sgid  != old->sgid ||
-            new->fsgid != old->fsgid)
+        if (!gid_eq(new->gid,   old->gid)  ||
+            !gid_eq(new->egid,  old->egid) ||
+            !gid_eq(new->sgid,  old->sgid) ||
+            !gid_eq(new->fsgid, old->fsgid))
                 proc_id_connector(task, PROC_EVENT_GID);
 
         /* release the old obj and subj refs both */
diff --git a/kernel/signal.c b/kernel/signal.c
index e2c5d84f2da..2734dc965f6 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1038,8 +1038,10 @@ static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_str
         if (SI_FROMKERNEL(info))
                 return;
 
-        info->si_uid = user_ns_map_uid(task_cred_xxx(t, user_ns),
-                                        current_cred(), info->si_uid);
+        rcu_read_lock();
+        info->si_uid = from_kuid_munged(task_cred_xxx(t, user_ns),
+                                        make_kuid(current_user_ns(), info->si_uid));
+        rcu_read_unlock();
 }
 #else
 static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_struct *t)
@@ -1106,7 +1108,7 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
                         q->info.si_code = SI_USER;
                         q->info.si_pid = task_tgid_nr_ns(current,
                                                         task_active_pid_ns(t));
-                        q->info.si_uid = current_uid();
+                        q->info.si_uid = from_kuid_munged(current_user_ns(), current_uid());
                         break;
                 case (unsigned long) SEND_SIG_PRIV:
                         q->info.si_signo = sig;
@@ -1973,7 +1975,7 @@ static void ptrace_do_notify(int signr, int exit_code, int why)
         info.si_signo = signr;
         info.si_code = exit_code;
         info.si_pid = task_pid_vnr(current);
-        info.si_uid = current_uid();
+        info.si_uid = from_kuid_munged(current_user_ns(), current_uid());
 
         /* Let the debugger run.  */
         ptrace_stop(exit_code, why, 1, &info);
@@ -2828,7 +2830,7 @@ SYSCALL_DEFINE2(kill, pid_t, pid, int, sig)
         info.si_errno = 0;
         info.si_code = SI_USER;
         info.si_pid = task_tgid_vnr(current);
-        info.si_uid = current_uid();
+        info.si_uid = from_kuid_munged(current_user_ns(), current_uid());
 
         return kill_something_info(sig, &info, pid);
 }
@@ -2871,7 +2873,7 @@ static int do_tkill(pid_t tgid, pid_t pid, int sig)
         info.si_errno = 0;
         info.si_code = SI_TKILL;
         info.si_pid = task_tgid_vnr(current);
-        info.si_uid = current_uid();
+        info.si_uid = from_kuid_munged(current_user_ns(), current_uid());
 
         return do_send_specific(tgid, pid, sig, &info);
 }
diff --git a/kernel/sys.c b/kernel/sys.c
index f0c43b4b665..39962818c00 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -175,7 +175,6 @@ SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
         const struct cred *cred = current_cred();
         int error = -EINVAL;
         struct pid *pgrp;
-        kuid_t cred_uid;
         kuid_t uid;
 
         if (which > PRIO_USER || which < PRIO_PROCESS)
@@ -209,22 +208,19 @@ SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
                         } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
                         break;
                 case PRIO_USER:
-                        cred_uid = make_kuid(cred->user_ns, cred->uid);
                         uid = make_kuid(cred->user_ns, who);
                         user = cred->user;
                         if (!who)
-                                uid = cred_uid;
-                        else if (!uid_eq(uid, cred_uid) &&
+                                uid = cred->uid;
+                        else if (!uid_eq(uid, cred->uid) &&
                                  !(user = find_user(uid)))
                                 goto out_unlock;        /* No processes for this user */
 
                         do_each_thread(g, p) {
-                                const struct cred *tcred = __task_cred(p);
-                                kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid);
-                                if (uid_eq(tcred_uid, uid))
+                                if (uid_eq(task_uid(p), uid))
                                         error = set_one_prio(p, niceval, error);
                         } while_each_thread(g, p);
-                        if (!uid_eq(uid, cred_uid))
+                        if (!uid_eq(uid, cred->uid))
                                 free_uid(user);         /* For find_user() */
                         break;
         }
@@ -248,7 +244,6 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
         const struct cred *cred = current_cred();
         long niceval, retval = -ESRCH;
         struct pid *pgrp;
-        kuid_t cred_uid;
         kuid_t uid;
 
         if (which > PRIO_USER || which < PRIO_PROCESS)
@@ -280,25 +275,22 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
                         } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
                         break;
                 case PRIO_USER:
-                        cred_uid = make_kuid(cred->user_ns, cred->uid);
                         uid = make_kuid(cred->user_ns, who);
                         user = cred->user;
                         if (!who)
-                                uid = cred_uid;
-                        else if (!uid_eq(uid, cred_uid) &&
+                                uid = cred->uid;
+                        else if (!uid_eq(uid, cred->uid) &&
                                  !(user = find_user(uid)))
                                 goto out_unlock;        /* No processes for this user */
 
                         do_each_thread(g, p) {
-                                const struct cred *tcred = __task_cred(p);
-                                kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid);
-                                if (uid_eq(tcred_uid, uid)) {
+                                if (uid_eq(task_uid(p), uid)) {
                                         niceval = 20 - task_nice(p);
                                         if (niceval > retval)
                                                 retval = niceval;
                                 }
                         } while_each_thread(g, p);
-                        if (!uid_eq(uid, cred_uid))
+                        if (!uid_eq(uid, cred->uid))
                                 free_uid(user);         /* for find_user() */
                         break;
         }
@@ -641,7 +633,7 @@ static int set_user(struct cred *new)
 {
         struct user_struct *new_user;
 
-        new_user = alloc_uid(make_kuid(new->user_ns, new->uid));
+        new_user = alloc_uid(new->uid);
         if (!new_user)
                 return -EAGAIN;
 
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 7eff867bfac..86602316422 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -36,8 +36,8 @@ static bool new_idmap_permitted(struct user_namespace *ns, int cap_setid,
 int create_user_ns(struct cred *new)
 {
         struct user_namespace *ns, *parent_ns = new->user_ns;
-        kuid_t owner = make_kuid(new->user_ns, new->euid);
-        kgid_t group = make_kgid(new->user_ns, new->egid);
+        kuid_t owner = new->euid;
+        kgid_t group = new->egid;
 
         /* The creator needs a mapping in the parent user namespace
          * or else we won't be able to reasonably tell userspace who