commit 32ec9839d89d2b814ada20b041b25feae23596bc
author Changbin Du <changbin.du@gmail.com> Mon Apr 27 21:24:12 2020 +0800
committer Gerd Hoffmann <kraxel@redhat.com> Thu May 14 14:26:42 2020 +0200
tree 0a2bc31e363684e3285564581a53a74674c1b164
parent df2ac3cc12d251dcdd268038682fd27882e91bb2

ui/sdl2: fix segment fault caused by null pointer dereference

I found SDL_GetWindowFromID() sometimes return NULL when I start qemu via
ssh forwarding even the window has been crated already. I am not sure
whether this is a bug of SDL, but we'd better check it carefully.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Message-id: 20200427132412.17909-1-changbin.du@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

ui/sdl2.c

diff --git a/ui/sdl2.c b/ui/sdl2.c
index 3c9424e..61c7956 100644
--- a/ui/sdl2.c
+++ b/ui/sdl2.c
@@ -332,6 +332,10 @@
     int gui_key_modifier_pressed = get_mod_state();
     int gui_keysym = 0;
 
+    if (!scon) {
+        return;
+    }
+
     if (!scon->ignore_hotkeys && gui_key_modifier_pressed && !ev->key.repeat) {
         switch (ev->key.keysym.scancode) {
         case SDL_SCANCODE_2:
@@ -412,6 +416,10 @@
 {
     struct sdl2_console *scon = get_scon_from_window(ev->key.windowID);
 
+    if (!scon) {
+        return;
+    }
+
     scon->ignore_hotkeys = false;
     sdl2_process_key(scon, &ev->key);
 }
@@ -421,6 +429,10 @@
     struct sdl2_console *scon = get_scon_from_window(ev->text.windowID);
     QemuConsole *con = scon ? scon->dcl.con : NULL;
 
+    if (!con) {
+        return;
+    }
+
     if (qemu_console_is_graphic(con)) {
         return;
     }