Limit the number of screens Xvfb will attempt to allocate memory for

Commit f9e3a2955d2ca7 removing the MAXSCREEN limit left the screen
number too unlimited, and allowed any positive int for a screen number:

Xvfb :1 -screen 2147483647 1024x1024x8

Fatal server error:
Not enough memory for screen 2147483647

Found by Parfait 0.3.7:
Error: Integer overflow (CWE 190)
   Integer parameter of memory allocation function realloc() may overflow due to multiplication with constant value 1112
        at line 293 of hw/vfb/InitOutput.c in function 'ddxProcessArgument'.

Since the X11 connection setup only has a CARD8 for number of SCREENS,
limit to 255 screens, which is also low enough to avoid overflow on the
sizeof(*vfbScreens) * (screenNum + 1) calculation for realloc.

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Jamey Sharp <jamey@minilop.net>

0 files changed, 0 insertions, 0 deletions