Fix wsl stuck when misconfigured cifs mount presents (#14466)

* detach terminal before running mount -a

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

* use _exit on error before execv in child process to avoid unintentional resource release

* Add regression test

* Fix clang format issue

* fix all clang format issue

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

* resolve ai comments

* move test to unit test

* Fix string literal

* Overwrite fstab to resolve pipeline missing file issue

---------

Co-authored-by: Feng Wang <wangfen@microsoft.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: 3 people

src/linux/init/config.cpp

@@ -2137,7 +2137,7 @@ Return Value:
     //
 
     const char* const Argv[] = {MOUNT_COMMAND, MOUNT_FSTAB_ARG, nullptr};
-    if (UtilCreateProcessAndWait(Argv[0], Argv, nullptr, {{WSL_DRVFS_ELEVATED_ENV, Elevated ? "1" : "0"}}) < 0)
+    if (UtilCreateProcessAndWait(Argv[0], Argv, nullptr, {{WSL_DRVFS_ELEVATED_ENV, Elevated ? "1" : "0"}}, true) < 0)
     {
         auto message = wsl::shared::Localization::MessageFstabMountFailed();
         LOG_ERROR("{}", message.c_str());

src/linux/init/util.cpp

@@ -613,7 +613,7 @@ Return Value:
     return SocketFd;
 }
 
-int UtilCreateProcessAndWait(const char* const File, const char* const Argv[], int* Status, const std::map<std::string, std::string>& Env)
+int UtilCreateProcessAndWait(const char* const File, const char* const Argv[], int* Status, const std::map<std::string, std::string>& Env, bool DetachTerminal)
 
 /*++
 
@@ -630,6 +630,9 @@ Routine Description:
     Status - Supplies an optional pointer that receives the exit status of the
         process.
 
+    DetachTerminal - Supplies a boolean that, when true, calls setsid() in the
+        child process to detach it from the controlling terminal.
+
 Return Value:
 
     0 on success, -1 on failure.
@@ -664,7 +667,7 @@ Return Value:
 
         if (UtilSetSignalHandlers(g_SavedSignalActions, false) < 0 || UtilRestoreBlockedSignals() < 0)
         {
-            exit(-1);
+            _exit(-1);
         }
 
         //
@@ -676,6 +679,19 @@ Return Value:
             setenv(e.first.c_str(), e.second.c_str(), 1);
         }
 
+        //
+        // Detach from the controlling terminal if requested.
+        //
+
+        if (DetachTerminal)
+        {
+            if (setsid() == -1)
+            {
+                LOG_ERROR("setsid failed {}", errno);
+                _exit(-1);
+            }
+        }
+
         //
         // Invoke the executable.
         //
@@ -686,7 +702,7 @@ Return Value:
         // with std::string anyway.
         execv(File, const_cast<char* const*>(Argv));
         LOG_ERROR("execv({}) failed with {}", File, errno);
-        exit(-1);
+        _exit(-1);
     }
 
     if (Status == nullptr)

src/linux/init/util.h

@@ -191,7 +191,8 @@ Return Value:
     _exit(1);
 }
 
-int UtilCreateProcessAndWait(const char* File, const char* const Argv[], int* Status = nullptr, const std::map<std::string, std::string>& Env = {});
+int UtilCreateProcessAndWait(
+    const char* File, const char* const Argv[], int* Status = nullptr, const std::map<std::string, std::string>& Env = {}, bool DetachTerminal = false);
 
 template <typename TMethod>
 void UtilCreateWorkerThread(const char* Name, TMethod&& ThreadFunction)

test/windows/UnitTests.cpp

@@ -6539,5 +6539,28 @@ Error code: Wsl/InstallDistro/WSL_E_INVALID_JSON\r\n",
         VERIFY_ARE_EQUAL(err, L"");
     }
 
+    TEST_METHOD(InteractiveMount)
+    {
+        WSL2_TEST_ONLY();
+
+        // Add a fake interactive mount helper.
+        DistroFileChange mountHelper(L"/sbin/mount.hang", false);
+        mountHelper.SetContent(
+            L"#!/bin/sh\n"
+            L"read pass < /dev/tty\n");
+        VERIFY_ARE_EQUAL(LxsstuLaunchWsl(L"chmod +x /sbin/mount.hang"), (DWORD)0);
+
+        // Don't keep the original fstab as it can be missing on the pipeline.
+        DistroFileChange fstab(L"/etc/fstab", false);
+        fstab.SetContent(L"none /mnt/ttytest hang 0 0\n");
+
+        // Restart the distro with this mount.
+        WslShutdown();
+        wsl::windows::common::SubProcess process(nullptr, LxssGenerateWslCommandLine(L"echo booted").c_str());
+        auto result = process.RunAndCaptureOutput(60 * 1000);
+        VERIFY_ARE_EQUAL(result.Stdout, L"booted\n");
+        VERIFY_ARE_EQUAL(result.ExitCode, 0);
+    }
+
 }; // namespace UnitTests
 } // namespace UnitTests