1 files changed, 80 insertions, 60 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index 17afcaf582d0..677102789cf2 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -29,6 +29,7 @@
 #include <linux/pid_namespace.h>
 #include <linux/nsproxy.h>
 #include <linux/user_namespace.h>
+#include <linux/uprobes.h>
 #define CREATE_TRACE_POINTS
 #include <trace/events/signal.h>
 
@@ -160,7 +161,7 @@ void recalc_sigpending(void)
 
 #define SYNCHRONOUS_MASK \
         (sigmask(SIGSEGV) | sigmask(SIGBUS) | sigmask(SIGILL) | \
-         sigmask(SIGTRAP) | sigmask(SIGFPE))
+         sigmask(SIGTRAP) | sigmask(SIGFPE) | sigmask(SIGSYS))
 
 int next_signal(struct sigpending *pending, sigset_t *mask)
 {
@@ -767,14 +768,13 @@ static int kill_ok_by_cred(struct task_struct *t)
         const struct cred *cred = current_cred();
         const struct cred *tcred = __task_cred(t);
 
-        if (cred->user->user_ns == tcred->user->user_ns &&
-            (cred->euid == tcred->suid ||
-             cred->euid == tcred->uid ||
-             cred->uid  == tcred->suid ||
-             cred->uid  == tcred->uid))
+        if (uid_eq(cred->euid, tcred->suid) ||
+            uid_eq(cred->euid, tcred->uid)  ||
+            uid_eq(cred->uid,  tcred->suid) ||
+            uid_eq(cred->uid,  tcred->uid))
                 return 1;
 
-        if (ns_capable(tcred->user->user_ns, CAP_KILL))
+        if (ns_capable(tcred->user_ns, CAP_KILL))
                 return 1;
 
         return 0;
@@ -1020,15 +1020,6 @@ static inline int legacy_queue(struct sigpending *signals, int sig)
         return (sig < SIGRTMIN) && sigismember(&signals->signal, sig);
 }
 
-/*
- * map the uid in struct cred into user namespace *ns
- */
-static inline uid_t map_cred_ns(const struct cred *cred,
-                                struct user_namespace *ns)
-{
-        return user_ns_map_uid(ns, cred, cred->uid);
-}
-
 #ifdef CONFIG_USER_NS
 static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_struct *t)
 {
@@ -1038,8 +1029,10 @@ 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 +1099,7 @@ 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;
@@ -1387,10 +1380,8 @@ static int kill_as_cred_perm(const struct cred *cred,
                              struct task_struct *target)
 {
         const struct cred *pcred = __task_cred(target);
-        if (cred->user_ns != pcred->user_ns)
-                return 0;
-        if (cred->euid != pcred->suid && cred->euid != pcred->uid &&
-            cred->uid  != pcred->suid && cred->uid  != pcred->uid)
+        if (!uid_eq(cred->euid, pcred->suid) && !uid_eq(cred->euid, pcred->uid) &&
+            !uid_eq(cred->uid,  pcred->suid) && !uid_eq(cred->uid,  pcred->uid))
                 return 0;
         return 1;
 }
@@ -1665,21 +1656,20 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
         info.si_signo = sig;
         info.si_errno = 0;
         /*
-         * we are under tasklist_lock here so our parent is tied to
-         * us and cannot exit and release its namespace.
+         * We are under tasklist_lock here so our parent is tied to
+         * us and cannot change.
          *
-         * the only it can is to switch its nsproxy with sys_unshare,
-         * bu uncharing pid namespaces is not allowed, so we'll always
-         * see relevant namespace
+         * task_active_pid_ns will always return the same pid namespace
+         * until a task passes through release_task.
          *
          * write_lock() currently calls preempt_disable() which is the
          * same as rcu_read_lock(), but according to Oleg, this is not
          * correct to rely on this
          */
         rcu_read_lock();
-        info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns);
-        info.si_uid = map_cred_ns(__task_cred(tsk),
-                        task_cred_xxx(tsk->parent, user_ns));
+        info.si_pid = task_pid_nr_ns(tsk, task_active_pid_ns(tsk->parent));
+        info.si_uid = from_kuid_munged(task_cred_xxx(tsk->parent, user_ns),
+                                       task_uid(tsk));
         rcu_read_unlock();
 
         info.si_utime = cputime_to_clock_t(tsk->utime + tsk->signal->utime);
@@ -1762,8 +1752,7 @@ static void do_notify_parent_cldstop(struct task_struct *tsk,
          */
         rcu_read_lock();
         info.si_pid = task_pid_nr_ns(tsk, parent->nsproxy->pid_ns);
-        info.si_uid = map_cred_ns(__task_cred(tsk),
-                        task_cred_xxx(parent, user_ns));
+        info.si_uid = from_kuid_munged(task_cred_xxx(parent, user_ns), task_uid(tsk));
         rcu_read_unlock();
 
         info.si_utime = cputime_to_clock_t(tsk->utime);
@@ -1973,7 +1962,7 @@ 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);
@@ -2181,8 +2170,8 @@ static int ptrace_signal(int signr, siginfo_t *info,
                 info->si_code = SI_USER;
                 rcu_read_lock();
                 info->si_pid = task_pid_vnr(current->parent);
-                info->si_uid = map_cred_ns(__task_cred(current->parent),
-                                current_user_ns());
+                info->si_uid = from_kuid_munged(current_user_ns(),
+                                                task_uid(current->parent));
                 rcu_read_unlock();
         }
 
@@ -2202,6 +2191,9 @@ int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka,
         struct signal_struct *signal = current->signal;
         int signr;
 
+        if (unlikely(uprobe_deny_signal()))
+                return 0;
+
 relock:
         /*
          * We'll jump back here after any time we were stopped in TASK_STOPPED.
@@ -2376,24 +2368,34 @@ relock:
 }
 
 /**
- * block_sigmask - add @ka's signal mask to current->blocked
- * @ka: action for @signr
- * @signr: signal that has been successfully delivered
+ * signal_delivered - 
+ * @sig:                number of signal being delivered
+ * @info:               siginfo_t of signal being delivered
+ * @ka:                 sigaction setting that chose the handler
+ * @regs:               user register state
+ * @stepping:           nonzero if debugger single-step or block-step in use
  *
  * This function should be called when a signal has succesfully been
- * delivered. It adds the mask of signals for @ka to current->blocked
- * so that they are blocked during the execution of the signal
- * handler. In addition, @signr will be blocked unless %SA_NODEFER is
- * set in @ka->sa.sa_flags.
+ * delivered. It updates the blocked signals accordingly (@ka->sa.sa_mask
+ * is always blocked, and the signal itself is blocked unless %SA_NODEFER
+ * is set in @ka->sa.sa_flags.  Tracing is notified.
  */
-void block_sigmask(struct k_sigaction *ka, int signr)
+void signal_delivered(int sig, siginfo_t *info, struct k_sigaction *ka,
+                        struct pt_regs *regs, int stepping)
 {
         sigset_t blocked;
 
+        /* A signal was successfully delivered, and the
+           saved sigmask was stored on the signal frame,
+           and will be restored by sigreturn.  So we can
+           simply clear the restore sigmask flag.  */
+        clear_restore_sigmask();
+
         sigorsets(&blocked, &current->blocked, &ka->sa.sa_mask);
         if (!(ka->sa.sa_flags & SA_NODEFER))
-                sigaddset(&blocked, signr);
+                sigaddset(&blocked, sig);
         set_current_blocked(&blocked);
+        tracehook_signal_handler(sig, info, ka, regs, stepping);
 }
 
 /*
@@ -2526,7 +2528,16 @@ static void __set_task_blocked(struct task_struct *tsk, const sigset_t *newset)
  * It is wrong to change ->blocked directly, this helper should be used
  * to ensure the process can't miss a shared signal we are going to block.
  */
-void set_current_blocked(const sigset_t *newset)
+void set_current_blocked(sigset_t *newset)
+{
+        struct task_struct *tsk = current;
+        sigdelsetmask(newset, sigmask(SIGKILL) | sigmask(SIGSTOP));
+        spin_lock_irq(&tsk->sighand->siglock);
+        __set_task_blocked(tsk, newset);
+        spin_unlock_irq(&tsk->sighand->siglock);
+}
+
+void __set_current_blocked(const sigset_t *newset)
 {
         struct task_struct *tsk = current;
 
@@ -2566,7 +2577,7 @@ int sigprocmask(int how, sigset_t *set, sigset_t *oldset)
                 return -EINVAL;
         }
 
-        set_current_blocked(&newset);
+        __set_current_blocked(&newset);
         return 0;
 }
 
@@ -2706,6 +2717,13 @@ int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from)
                 err |= __put_user(from->si_uid, &to->si_uid);
                 err |= __put_user(from->si_ptr, &to->si_ptr);
                 break;
+#ifdef __ARCH_SIGSYS
+        case __SI_SYS:
+                err |= __put_user(from->si_call_addr, &to->si_call_addr);
+                err |= __put_user(from->si_syscall, &to->si_syscall);
+                err |= __put_user(from->si_arch, &to->si_arch);
+                break;
+#endif
         default: /* this is just in case for now ... */
                 err |= __put_user(from->si_pid, &to->si_pid);
                 err |= __put_user(from->si_uid, &to->si_uid);
@@ -2828,7 +2846,7 @@ 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 +2889,7 @@ 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);
 }
@@ -3133,7 +3151,7 @@ SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, nset,
                         return -EINVAL;
                 }
 
-                set_current_blocked(&new_blocked);
+                __set_current_blocked(&new_blocked);
         }
 
         if (oset) {
@@ -3197,7 +3215,6 @@ SYSCALL_DEFINE1(ssetmask, int, newmask)
         int old = current->blocked.sig[0];
         sigset_t newset;
 
-        siginitset(&newset, newmask & ~(sigmask(SIGKILL) | sigmask(SIGSTOP)));
         set_current_blocked(&newset);
 
         return old;
@@ -3236,6 +3253,17 @@ SYSCALL_DEFINE0(pause)
 
 #endif
 
+int sigsuspend(sigset_t *set)
+{
+        current->saved_sigmask = current->blocked;
+        set_current_blocked(set);
+
+        current->state = TASK_INTERRUPTIBLE;
+        schedule();
+        set_restore_sigmask();
+        return -ERESTARTNOHAND;
+}
+
 #ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND
 /**
  *  sys_rt_sigsuspend - replace the signal mask for a value with the
@@ -3253,15 +3281,7 @@ SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize)
 
         if (copy_from_user(&newset, unewset, sizeof(newset)))
                 return -EFAULT;
-        sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP));
-
-        current->saved_sigmask = current->blocked;
-        set_current_blocked(&newset);
-
-        current->state = TASK_INTERRUPTIBLE;
-        schedule();
-        set_restore_sigmask();
-        return -ERESTARTNOHAND;
+        return sigsuspend(&newset);
 }
 #endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */