1 files changed, 13 insertions, 46 deletions

diff --git a/ipc/ipc_channel_posix.cc b/ipc/ipc_channel_posix.cc
index 22e4781..d9156d7 100644
--- a/ipc/ipc_channel_posix.cc
+++ b/ipc/ipc_channel_posix.cc
@@ -193,6 +193,19 @@ bool CreateServerUnixDomainSocket(const std::string& pipe_name,
     return false;
   }
 
+  // Explicitly set file system permissions on socket, mainly as a precaution
+  // for Chrome OS.
+  // Do not rely on these file permissions to provide security - the file is
+  // created during the above bind() call so there is still a window for
+  // malicious abuse because the file exists between bind() and chmod(). Also,
+  // the file permissions may not be enforced for unix sockets on all platforms.
+  if (chmod(pipe_name.c_str(), 0600)) {
+    PLOG(ERROR) << "chmod " << pipe_name;
+    if (HANDLE_EINTR(close(fd)) < 0)
+      PLOG(ERROR) << "close " << pipe_name;
+    return false;
+  }
+
   // Start listening on the socket.
   const int listen_queue_length = 1;
   if (listen(fd, listen_queue_length) != 0) {
@@ -925,33 +938,6 @@ bool Channel::ChannelImpl::HasAcceptedConnection() const {
   return AcceptsConnections() && pipe_ != -1;
 }
 
-bool Channel::ChannelImpl::GetClientEuid(uid_t* client_euid) const {
-  DCHECK(HasAcceptedConnection());
-#if defined(OS_MACOSX)
-  uid_t peer_euid;
-  gid_t peer_gid;
-  if (getpeereid(pipe_, &peer_euid, &peer_gid) != 0) {
-    PLOG(ERROR) << "getpeereid " << pipe_;
-    return false;
-  }
-  *client_euid = peer_euid;
-  return true;
-#else
-  struct ucred cred;
-  socklen_t cred_len = sizeof(cred);
-  if (getsockopt(pipe_, SOL_SOCKET, SO_PEERCRED, &cred, &cred_len) != 0) {
-    PLOG(ERROR) << "getsockopt " << pipe_;
-    return false;
-  }
-  if (cred_len < sizeof(cred)) {
-    NOTREACHED() << "Truncated ucred from SO_PEERCRED?";
-    return false;
-  }
-  *client_euid = cred.uid;
-  return true;
-#endif
-}
-
 void Channel::ChannelImpl::ResetToAcceptingConnectionState() {
   // Unregister libevent for the unix domain socket and close it.
   read_watcher_.StopWatchingFileDescriptor();
@@ -1011,21 +997,6 @@ void Channel::ChannelImpl::OnFileCanReadWithoutBlocking(int fd) {
     }
     pipe_ = new_pipe;
 
-    if ((mode_ & MODE_OPEN_ACCESS_FLAG) == 0) {
-      // Verify that the IPC channel peer is running as the same user.
-      uid_t client_euid;
-      if (!GetClientEuid(&client_euid)) {
-        LOG(ERROR) << "Unable to query client euid";
-        ResetToAcceptingConnectionState();
-        return;
-      }
-      if (client_euid != geteuid()) {
-        LOG(WARNING) << "Client euid is not authorised";
-        ResetToAcceptingConnectionState();
-        return;
-      }
-    }
-
     if (!AcceptConnection()) {
       NOTREACHED() << "AcceptConnection should not fail on server";
     }
@@ -1190,10 +1161,6 @@ bool Channel::HasAcceptedConnection() const {
   return channel_impl_->HasAcceptedConnection();
 }
 
-bool Channel::GetClientEuid(uid_t* client_euid) const {
-  return channel_impl_->GetClientEuid(client_euid);
-}
-
 void Channel::ResetToAcceptingConnectionState() {
   channel_impl_->ResetToAcceptingConnectionState();
 }