1 files changed, 19 insertions, 9 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index e93ff0a719a0..60d80ab2601c 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -37,6 +37,7 @@
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
 #include <asm/siginfo.h>
+#include <asm/cacheflush.h>
 #include "audit.h"      /* audit_signal_info() */
 
 /*
@@ -59,21 +60,20 @@ static int sig_handler_ignored(void __user *handler, int sig)
                 (handler == SIG_DFL && sig_kernel_ignore(sig));
 }
 
-static int sig_task_ignored(struct task_struct *t, int sig,
-                int from_ancestor_ns)
+static int sig_task_ignored(struct task_struct *t, int sig, bool force)
 {
         void __user *handler;
 
         handler = sig_handler(t, sig);
 
         if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) &&
-                        handler == SIG_DFL && !from_ancestor_ns)
+                        handler == SIG_DFL && !force)
                 return 1;
 
         return sig_handler_ignored(handler, sig);
 }
 
-static int sig_ignored(struct task_struct *t, int sig, int from_ancestor_ns)
+static int sig_ignored(struct task_struct *t, int sig, bool force)
 {
         /*
          * Blocked signals are never ignored, since the
@@ -83,7 +83,7 @@ static int sig_ignored(struct task_struct *t, int sig, int from_ancestor_ns)
         if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig))
                 return 0;
 
-        if (!sig_task_ignored(t, sig, from_ancestor_ns))
+        if (!sig_task_ignored(t, sig, force))
                 return 0;
 
         /*
@@ -856,7 +856,7 @@ static void ptrace_trap_notify(struct task_struct *t)
  * Returns true if the signal should be actually delivered, otherwise
  * it should be dropped.
  */
-static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns)
+static int prepare_signal(int sig, struct task_struct *p, bool force)
 {
         struct signal_struct *signal = p->signal;
         struct task_struct *t;
@@ -916,7 +916,7 @@ static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns)
                 }
         }
 
-        return !sig_ignored(p, sig, from_ancestor_ns);
+        return !sig_ignored(p, sig, force);
 }
 
 /*
@@ -1060,7 +1060,8 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
         assert_spin_locked(&t->sighand->siglock);
 
         result = TRACE_SIGNAL_IGNORED;
-        if (!prepare_signal(sig, t, from_ancestor_ns))
+        if (!prepare_signal(sig, t,
+                        from_ancestor_ns || (info == SEND_SIG_FORCED)))
                 goto ret;
 
         pending = group ? &t->signal->shared_pending : &t->pending;
@@ -1602,7 +1603,7 @@ int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)
 
         ret = 1; /* the signal is ignored */
         result = TRACE_SIGNAL_IGNORED;
-        if (!prepare_signal(sig, t, 0))
+        if (!prepare_signal(sig, t, false))
                 goto out;
 
         ret = 0;
@@ -1653,6 +1654,15 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
         BUG_ON(!tsk->ptrace &&
                (tsk->group_leader != tsk || !thread_group_empty(tsk)));
 
+        if (sig != SIGCHLD) {
+                /*
+                 * This is only possible if parent == real_parent.
+                 * Check if it has changed security domain.
+                 */
+                if (tsk->parent_exec_id != tsk->parent->self_exec_id)
+                        sig = SIGCHLD;
+        }
+
         info.si_signo = sig;
         info.si_errno = 0;
         /*