Linux sandbox: restrict *kill to the current process.

sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Note: any code in this file MUST be async-signal safe.
 
 #include "sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.h"
 
 #include <unistd.h>
 
 #include "base/basictypes.h"
 #include "base/posix/eintr_wrapper.h"
 #include "build/build_config.h"
 #include "sandbox/linux/seccomp-bpf/sandbox_bpf.h"
 
 #define SECCOMP_MESSAGE_COMMON_CONTENT "seccomp-bpf failure"
 #define SECCOMP_MESSAGE_CLONE_CONTENT "clone() failure"
 #define SECCOMP_MESSAGE_PRCTL_CONTENT "prctl() failure"
 #define SECCOMP_MESSAGE_IOCTL_CONTENT "ioctl() failure"
+#define SECCOMP_MESSAGE_KILL_CONTENT "(tg)kill() failure"
 
 namespace {
 
 inline bool IsArchitectureX86_64() {
 #if defined(__x86_64__)
   return true;
 #else
   return false;
 #endif
 }
@@ skipping 110 matching lines @@
   volatile uint64_t request = args.args[1];
   volatile char* addr = reinterpret_cast<volatile char*>(request & 0xFFFF);
   *addr = '\0';
   // Hit the NULL page if this fails.
   addr = reinterpret_cast<volatile char*>(request & 0xFFF);
   *addr = '\0';
   for (;;)
     _exit(1);
 }
 
+intptr_t SIGSYSKillFailure(const struct arch_seccomp_data& args,
+                           void* /* aux */) {
+   static const char kSeccompKillError[] =
+      __FILE__":**CRASHING**:" SECCOMP_MESSAGE_KILL_CONTENT "\n";
+  WriteToStdErr(kSeccompKillError, sizeof(kSeccompKillError) - 1);
+  // Make "request" volatile so that we can see it on the stack in a minidump.
+  volatile uint64_t pid = args.args[0];
+  volatile char* addr = reinterpret_cast<volatile char*>(pid & 0xFFF);
+  *addr = '\0';
+  // Hit the NULL page if this fails.
+  addr = reinterpret_cast<volatile char*>(pid & 0xFFF);
+  *addr = '\0';
+  for (;;)
+    _exit(1);
+}
+
 const char* GetErrorMessageContentForTests() {
   return SECCOMP_MESSAGE_COMMON_CONTENT;
 }
 
 const char* GetCloneErrorMessageContentForTests() {
   return SECCOMP_MESSAGE_CLONE_CONTENT;
 }
 
 const char* GetPrctlErrorMessageContentForTests() {
   return SECCOMP_MESSAGE_PRCTL_CONTENT;
 }
 
 const char* GetIoctlErrorMessageContentForTests() {
   return SECCOMP_MESSAGE_IOCTL_CONTENT;
 }
 
 }  // namespace sandbox.