diff --git a/tools/power/x86/intel-speed-select/isst-daemon.c b/tools/power/x86/intel-speed-select/isst-daemon.c index 66df21b2b573..acedb7432849 100644 --- a/tools/power/x86/intel-speed-select/isst-daemon.c +++ b/tools/power/x86/intel-speed-select/isst-daemon.c @@ -148,6 +148,7 @@ static void daemonize(char *rundir, char *pidfile) { int pid, sid, i; char str[10]; + struct stat st; struct sigaction sig_actions; sigset_t sig_set; int ret; @@ -200,11 +201,17 @@ static void daemonize(char *rundir, char *pidfile) if (ret == -1) exit(EXIT_FAILURE); - pid_file_handle = open(pidfile, O_RDWR | O_CREAT, 0600); + pid_file_handle = open(pidfile, O_RDWR | O_CREAT | O_NOFOLLOW, 0600); if (pid_file_handle == -1) { /* Couldn't open lock file */ exit(1); } + + if (fstat(pid_file_handle, &st) == -1) + exit(1); + + if (!S_ISREG(st.st_mode)) + exit(1); /* Try to lock file */ #ifdef LOCKF_SUPPORT if (lockf(pid_file_handle, F_TLOCK, 0) == -1) {