From a09f347c6cc0b2821557d1346c4733cc78a79ffa Mon Sep 17 00:00:00 2001 From: Aaro Koskinen Date: Wed, 12 Sep 2012 00:44:37 +0300 Subject: [PATCH] staging: xgifb: validate the mode against video memory size It's possible to select video mode that exceeds the available video memory. This is potentially dangerous, fix by adding a check. The patch fixes system hangs seen occasionally when playing random videos with mplayer. Signed-off-by: Aaro Koskinen Signed-off-by: Greg Kroah-Hartman --- drivers/staging/xgifb/XGI_main_26.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/staging/xgifb/XGI_main_26.c b/drivers/staging/xgifb/XGI_main_26.c index 7fc3049..ba6c347 100644 --- a/drivers/staging/xgifb/XGI_main_26.c +++ b/drivers/staging/xgifb/XGI_main_26.c @@ -329,6 +329,7 @@ static int XGIfb_validate_mode(struct xgifb_video_info *xgifb_info, int myindex) { u16 xres, yres; struct xgi_hw_device_info *hw_info = &xgifb_info->hw_info; + unsigned long required_mem; if (xgifb_info->chip == XG21) { if (xgifb_info->display2 == XGIFB_DISP_LCD) { @@ -345,13 +346,13 @@ static int XGIfb_validate_mode(struct xgifb_video_info *xgifb_info, int myindex) } } - return myindex; + goto check_memory; } /* FIXME: for now, all is valid on XG27 */ if (xgifb_info->chip == XG27) - return myindex; + goto check_memory; if (!(XGIbios_mode[myindex].chipset & MD_XGI315)) return -1; @@ -539,6 +540,12 @@ static int XGIfb_validate_mode(struct xgifb_video_info *xgifb_info, int myindex) case XGIFB_DISP_NONE: break; } + +check_memory: + required_mem = XGIbios_mode[myindex].xres * XGIbios_mode[myindex].yres * + XGIbios_mode[myindex].bpp / 8; + if (required_mem > xgifb_info->video_size) + return -1; return myindex; } -- 2.7.4