cmdutils: remove the current working directory from the DLL search path on win32

Reviewed-by: Matt Oliver <protogonoi@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 3bf142c77337814458ed8e036796934032d9837f)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

6 files changed, 21 insertions, 0 deletions

diff --git a/cmdutils.c b/cmdutils.c
index 03a4836207..6960f8c99c 100644
--- a/cmdutils.c
+++ b/cmdutils.c
@@ -107,6 +107,15 @@ static void log_callback_report(void *ptr, int level, const char *fmt, va_list v
     }
 }
 
+void init_dynload(void)
+{
+#ifdef _WIN32
+    /* Calling SetDllDirectory with the empty string (but not NULL) removes the
+     * current working directory from the DLL search path as a security pre-caution. */
+    SetDllDirectory("");
+#endif
+}
+
 static void (*program_exit)(int ret);
 
 void register_exit(void (*cb)(int ret))
diff --git a/cmdutils.h b/cmdutils.h
index 83ea4ad39e..67bf4848b7 100644
--- a/cmdutils.h
+++ b/cmdutils.h
@@ -62,6 +62,11 @@ void register_exit(void (*cb)(int ret));
 void exit_program(int ret) av_noreturn;
 
 /**
+ * Initialize dynamic library loading
+ */
+void init_dynload(void);
+
+/**
  * Initialize the cmdutils option system, in particular
  * allocate the *_opts contexts.
  */
diff --git a/ffmpeg.c b/ffmpeg.c
index 9352b24004..435ad5730c 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -4268,6 +4268,8 @@ int main(int argc, char **argv)
     int ret;
     int64_t ti;
 
+    init_dynload();
+
     register_exit(ffmpeg_cleanup);
 
     setvbuf(stderr,NULL,_IONBF,0); /* win32 runtime needs this */
diff --git a/ffplay.c b/ffplay.c
index 97c356f835..22c530bb87 100644
--- a/ffplay.c
+++ b/ffplay.c
@@ -3771,6 +3771,8 @@ int main(int argc, char **argv)
     VideoState *is;
     char dummy_videodriver[] = "SDL_VIDEODRIVER=dummy";
 
+    init_dynload();
+
     av_log_set_flags(AV_LOG_SKIP_REPEATED);
     parse_loglevel(argc, argv, options);
 
diff --git a/ffprobe.c b/ffprobe.c
index f7b51adda2..4f23bddb69 100644
--- a/ffprobe.c
+++ b/ffprobe.c
@@ -3178,6 +3178,8 @@ int main(int argc, char **argv)
     char *w_name = NULL, *w_args = NULL;
     int ret, i;
 
+    init_dynload();
+
     av_log_set_flags(AV_LOG_SKIP_REPEATED);
     register_exit(ffprobe_cleanup);
 
diff --git a/ffserver.c b/ffserver.c
index 35e399dc55..d73caee9ec 100644
--- a/ffserver.c
+++ b/ffserver.c
@@ -3975,6 +3975,7 @@ int main(int argc, char **argv)
     int cfg_parsed;
     int ret = EXIT_FAILURE;
 
+    init_dynload();
 
     config.filename = av_strdup("/etc/ffserver.conf");