From 94cf0b522bf316c049824016bea74758752f9320 Mon Sep 17 00:00:00 2001
From: Andrea Mazzoleni <amadvance@gmail.com>
Date: Sat, 1 Aug 2026 18:26:01 +0200
Subject: [PATCH] Configure PR_SET_PDEATHSIG on Linux and Job Objects on
 Windows to prevent orphaned subprocesses on program crash

---
 configure.ac  |  9 +++------
 os/mingw.c    | 22 ++++++++++++++++++++++
 os/portable.h |  5 ++++-
 os/unix.c     | 24 ++++++++++++++++++++++++
 4 files changed, 53 insertions(+), 7 deletions(-)

diff --git a/configure.ac b/configure.ac
index 9fea8247..88459839 100644
--- a/configure.ac
+++ b/configure.ac
@@ -70,12 +70,9 @@ dnl Checks for header files.
 AC_HEADER_ASSERT
 AC_HEADER_DIRENT
 AC_HEADER_SYS_WAIT
-AC_CHECK_HEADERS([fcntl.h stddef.h stdint.h stdlib.h string.h limits.h time.h sys/time.h])
-AC_CHECK_HEADERS([unistd.h getopt.h io.h inttypes.h byteswap.h])
-AC_CHECK_HEADERS([pthread.h math.h syslog.h grp.h pwd.h])
-AC_CHECK_HEADERS([sys/file.h sys/ioctl.h sys/sysmacros.h sys/mkdev.h sys/mount.h])
-AC_CHECK_HEADERS([linux/fiemap.h linux/fs.h linux/btrfs.h execinfo.h])
-AC_CHECK_HEADERS([mach/mach_time.h sys/sysctl.h])
+AC_CHECK_HEADERS([stdint.h inttypes.h unistd.h math.h execinfo.h strings.h getopt.h syslog.h grp.h pwd.h io.h])
+AC_CHECK_HEADERS([sys/file.h sys/sysctl.h sys/ioctl.h sys/time.h sys/types.h sys/mkdev.h sys/sysmacros.h sys/stat.h sys/prctl.h sys/sysinfo.h sys/utsname.h])
+AC_CHECK_HEADERS([linux/fs.h linux/btrfs.h linux/fiemap.h mach/mach_time.h])
 
 # Check for the close_range(...,CLOSE_RANGE_CLOEXEC)
 AC_CHECK_HEADERS([linux/close_range.h])
diff --git a/os/mingw.c b/os/mingw.c
index 01ed8722..0e86120d 100644
--- a/os/mingw.c
+++ b/os/mingw.c
@@ -2531,6 +2531,8 @@ static int argcat(WCHAR* cmd, int size, int pos, const WCHAR* arg)
 	return pos;
 }
 
+static HANDLE os_job_handle = NULL;
+
 pid_t os_spawn(char** argv, int* stdout_read_int, int* stderr_read_int, const char* run_as_user)
 {
 	wchar_t conv[CONV_MAX];
@@ -2743,6 +2745,14 @@ pid_t os_spawn(char** argv, int* stdout_read_int, int* stderr_read_int, const ch
 		return -1;
 	}
 
+	/*
+	 * Assign spawned process to Job Object configured with JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE.
+	 * This ensures Windows automatically terminates child processes if the daemon crashes unexpectedly.
+	 */
+	if (os_job_handle != NULL) {
+		AssignProcessToJobObject(os_job_handle, pi.hProcess);
+	}
+
 	/* close the write end of the pipes in the parent */
 	if (has_out) {
 		CloseHandle(stdout_write_handle);
@@ -3526,6 +3536,18 @@ void os_init(unsigned opt)
 		os_exit();
 	}
 
+	/* initialize job object to terminate child processes if daemon dies */
+	os_job_handle = CreateJobObjectW(NULL, NULL);
+	if (os_job_handle != NULL) {
+		JOBOBJECT_EXTENDED_LIMIT_INFORMATION info;
+		ZeroMemory(&info, sizeof(info));
+		info.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE;
+		if (!SetInformationJobObject(os_job_handle, JobObjectExtendedLimitInformation, &info, sizeof(info))) {
+			CloseHandle(os_job_handle);
+			os_job_handle = NULL;
+		}
+	}
+
 	/* check for Wine presence */
 	is_wine = GetProcAddress(ntdll, "wine_get_version") != 0;
 
diff --git a/os/portable.h b/os/portable.h
index 4dc0460e..bd96b64e 100644
--- a/os/portable.h
+++ b/os/portable.h
@@ -217,6 +217,10 @@
 #include <sys/wait.h>
 #endif
 
+#if HAVE_SYS_PRCTL_H
+#include <sys/prctl.h>
+#endif
+
 #if HAVE_GETOPT_H
 #include <getopt.h>
 #endif
@@ -309,4 +313,3 @@
 #endif
 
 #endif
-
diff --git a/os/unix.c b/os/unix.c
index 4522e4b1..8e2c27a9 100644
--- a/os/unix.c
+++ b/os/unix.c
@@ -783,6 +783,14 @@ int os_script(char** argv, char** envp, const char* run_as_user)
 		 */
 		setpgid(0, 0);
 
+#if defined(__linux__) && defined(PR_SET_PDEATHSIG)
+		/* Send SIGKILL to child if parent daemon dies unexpectedly */
+		prctl(PR_SET_PDEATHSIG, SIGKILL);
+		if (getppid() == 1) {
+			_exit(127);
+		}
+#endif
+
 		/* drop privileges first (if configured) */
 		if (run_as_user && run_as_user[0] != 0) {
 			errno = 0;
@@ -954,6 +962,14 @@ int os_command(const char* command, const char* run_as_user, const char* stdin_t
 		 */
 		setpgid(0, 0);
 
+#if defined(__linux__) && defined(PR_SET_PDEATHSIG)
+		/* Send SIGKILL to child if parent daemon dies unexpectedly */
+		prctl(PR_SET_PDEATHSIG, SIGKILL);
+		if (getppid() == 1) {
+			_exit(127);
+		}
+#endif
+
 		if (pipe_fds[1] != -1)
 			close(pipe_fds[1]); /* Close unused write end */
 
@@ -1177,6 +1193,14 @@ pid_t os_spawn(char** argv, int* stdout_read_fd, int* stderr_read_fd, const char
 
 		setpgid(0, 0);
 
+#if defined(__linux__) && defined(PR_SET_PDEATHSIG)
+		/* Send SIGKILL to child if parent daemon dies unexpectedly */
+		prctl(PR_SET_PDEATHSIG, SIGKILL);
+		if (getppid() == 1) {
+			_exit(127);
+		}
+#endif
+
 		/* drop privileges first (if configured) */
 		if (run_as_user && run_as_user[0] != 0) {
 			errno = 0;