1 files changed, 36 insertions, 9 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index e5f8aea78ffe..7fe874d12fae 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -10,7 +10,6 @@
  *              to allow signals to be sent reliably.
  */
 
-#include <linux/config.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/smp_lock.h>
@@ -23,12 +22,12 @@
 #include <linux/syscalls.h>
 #include <linux/ptrace.h>
 #include <linux/signal.h>
-#include <linux/audit.h>
 #include <linux/capability.h>
 #include <asm/param.h>
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
 #include <asm/siginfo.h>
+#include "audit.h"      /* audit_signal_info() */
 
 /*
  * SLAB caches for signal bits.
@@ -584,7 +583,7 @@ static int check_kill_permission(int sig, struct siginfo *info,
             && !capable(CAP_KILL))
                 return error;
 
-        error = security_task_kill(t, info, sig);
+        error = security_task_kill(t, info, sig, 0);
         if (!error)
                 audit_signal_info(sig, t); /* Let audit system see the signal */
         return error;
@@ -1107,7 +1106,7 @@ kill_proc_info(int sig, struct siginfo *info, pid_t pid)
 
 /* like kill_proc_info(), but doesn't use uid/euid of "current" */
 int kill_proc_info_as_uid(int sig, struct siginfo *info, pid_t pid,
-                      uid_t uid, uid_t euid)
+                      uid_t uid, uid_t euid, u32 secid)
 {
         int ret = -EINVAL;
         struct task_struct *p;
@@ -1127,6 +1126,9 @@ int kill_proc_info_as_uid(int sig, struct siginfo *info, pid_t pid,
                 ret = -EPERM;
                 goto out_unlock;
         }
+        ret = security_task_kill(p, info, sig, secid);
+        if (ret)
+                goto out_unlock;
         if (sig && p->sighand) {
                 unsigned long flags;
                 spin_lock_irqsave(&p->sighand->siglock, flags);
@@ -1531,6 +1533,35 @@ static void do_notify_parent_cldstop(struct task_struct *tsk, int why)
         spin_unlock_irqrestore(&sighand->siglock, flags);
 }
 
+static inline int may_ptrace_stop(void)
+{
+        if (!likely(current->ptrace & PT_PTRACED))
+                return 0;
+
+        if (unlikely(current->parent == current->real_parent &&
+                    (current->ptrace & PT_ATTACHED)))
+                return 0;
+
+        if (unlikely(current->signal == current->parent->signal) &&
+            unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
+                return 0;
+
+        /*
+         * Are we in the middle of do_coredump?
+         * If so and our tracer is also part of the coredump stopping
+         * is a deadlock situation, and pointless because our tracer
+         * is dead so don't allow us to stop.
+         * If SIGKILL was already sent before the caller unlocked
+         * ->siglock we must see ->core_waiters != 0. Otherwise it
+         * is safe to enter schedule().
+         */
+        if (unlikely(current->mm->core_waiters) &&
+            unlikely(current->mm == current->parent->mm))
+                return 0;
+
+        return 1;
+}
+
 /*
  * This must be called with current->sighand->siglock held.
  *
@@ -1559,11 +1590,7 @@ static void ptrace_stop(int exit_code, int nostop_code, siginfo_t *info)
         spin_unlock_irq(&current->sighand->siglock);
         try_to_freeze();
         read_lock(&tasklist_lock);
-        if (likely(current->ptrace & PT_PTRACED) &&
-            likely(current->parent != current->real_parent ||
-                   !(current->ptrace & PT_ATTACHED)) &&
-            (likely(current->parent->signal != current->signal) ||
-             !unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))) {
+        if (may_ptrace_stop()) {
                 do_notify_parent_cldstop(current, CLD_TRAPPED);
                 read_unlock(&tasklist_lock);
                 schedule();