Chris Leishman wrote: > > On Sun, Nov 19, 2000 at 06:04:01AM -0900, Ethan Benson wrote: > > > > does anyone know why debian has /dev/fb* with 622 permissions? > > > > the reason i ask is there is a pretty nasty security problem with > > this, try the following: > > > > cat /dev/urandom > /dev/fb0 > > > > on my system i get a instant kernel panic (2.2.17 from ftp.kernel.org). > > since the framebuffer devices are world writable anyone with a shell > > account can crash the system, not nice. (i have a blue G3 using > > aty128fb) > > > > what is broken by setting the permissions on all the framebuffer > > devices to 0600 ?
Only all apps which need a framebuffer device to work... > Doesn't crash my i386 (riva tnt2, XF4) - but does put pretty colors over > the top 1/3 of the screen before cat exits with "write error: No space left > on device". Yep, I think the crash is a bug in the framebuffer device, just like the other problem where even reading from /dev/fb* caused a crash with atyfb IIRC. Michel -- Earthling Michel Dänzer (MrCooper) \ CS student and free software enthusiast Debian GNU/Linux (powerpc,i386) user \ member of XFree86 and The DRI Project
