fbmem: add margin check to fb_check_caps()

A fb_ioctl() FBIOPUT_VSCREENINFO call with invalid xres setting
or yres setting in struct fb_var_screeninfo will result in a
KASAN: vmalloc-out-of-bounds failure in bitfill_aligned() as
the margins are being cleared. The margins are cleared in
chunks and if the xres setting or yres setting is a value of
zero upto the chunk size, the failure will occur.

Add a margin check to validate xres and yres settings.

Signed-off-by: George Kennedy <[email protected]>
Reported-by: [email protected]
Reviewed-by: Dan Carpenter <[email protected]>
Cc: Dhaval Giani <[email protected]>
Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

0 files changed, 0 insertions, 0 deletions