[PATCH 1/4] staging: xgifb: validate the mode against video memory size
Aaro Koskinen
aaro.koskinen at iki.fi
Tue Sep 11 21:44:37 UTC 2012
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 <aaro.koskinen at iki.fi>
---
drivers/staging/xgifb/XGI_main_26.c | 11 +++++++++--
1 files 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;
}
--
1.7.2.5
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