diff options
| author | Yizhuo Zhai <yzhai003@ucr.edu> | 2022-02-02 15:58:08 -0800 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2022-02-03 13:52:03 +0100 |
| commit | 68e8cc2a23b61862bf20ffc9b782a3fb49c65568 (patch) | |
| tree | 763ffd34b281e100ed6f19df7f495956e7d472d6 /drivers/video | |
| parent | 622c9a3a7868e1eeca39c55305ca3ebec4742b64 (diff) | |
fbdev: fbmem: Fix the implicit type casting
In function do_fb_ioctl(), the "arg" is the type of unsigned long,
and in "case FBIOBLANK:" this argument is casted into an int before
passig to fb_blank(). In fb_blank(), the comparision
if (blank > FB_BLANK_POWERDOWN) would be bypass if the original
"arg" is a large number, which is possible because it comes from
the user input. Fix this by adding the check before the function
call.
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Yizhuo Zhai <yzhai003@ucr.edu>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220202235811.1621017-1-yzhai003@ucr.edu
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/fbdev/core/fbmem.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 0fa7ede94fa6..13083ad8d751 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1160,6 +1160,8 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, ret = fbcon_set_con2fb_map_ioctl(argp); break; case FBIOBLANK: + if (arg > FB_BLANK_POWERDOWN) + return -EINVAL; console_lock(); lock_fb_info(info); ret = fb_blank(info, arg); |