linux/drivers/video/fbdev/core
Tetsuo Handa 8c28051cdc fbmem: don't allow too huge resolutions
syzbot is reporting page fault at vga16fb_fillrect() [1], for
vga16fb_check_var() is failing to detect multiplication overflow.

  if (vxres * vyres > maxmem) {
    vyres = maxmem / vxres;
    if (vyres < yres)
      return -ENOMEM;
  }

Since no module would accept too huge resolutions where multiplication
overflow happens, let's reject in the common path.

Link: https://syzkaller.appspot.com/bug?extid=04168c8063cfdde1db5e [1]
Reported-by: syzbot <syzbot+04168c8063cfdde1db5e@syzkaller.appspotmail.com>
Debugged-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/185175d6-227a-7b55-433d-b070929b262c@i-love.sakura.ne.jp
2021-09-08 18:52:04 +02:00
..
Makefile
bitblit.c
cfbcopyarea.c
cfbfillrect.c
cfbimgblt.c
fb_cmdline.c
fb_ddc.c
fb_defio.c Revert "fb_defio: Remove custom address_space_operations" 2021-06-01 17:38:40 +02:00
fb_draw.h
fb_notify.c
fb_sys_fops.c
fbcmap.c fbdev: zero-fill colormap in fbcmap.c 2021-04-10 11:12:08 +02:00
fbcon.c tty: vt: always invoke vc->vc_sw->con_resize callback 2021-05-15 08:12:12 -07:00
fbcon.h
fbcon_ccw.c
fbcon_cw.c
fbcon_rotate.c
fbcon_rotate.h
fbcon_ud.c
fbcvt.c
fbmem.c fbmem: don't allow too huge resolutions 2021-09-08 18:52:04 +02:00
fbmon.c
fbsysfs.c
modedb.c
softcursor.c
svgalib.c
syscopyarea.c
sysfillrect.c
sysimgblt.c
tileblit.c