在 2020/3/3 22:46, Ville Syrjälä 写道:
On Tue, Mar 03, 2020 at 10:30:14PM +0800, zhangxiaoxu (A) wrote:
在 2020/3/3 21:59, Ville Syrjälä 写道:
That doesn't match how vc_screenbuf_size is computed elsewhere. Also
a lot of places seem to assume that the screenbuf can be larger than
vga_vram_size (eg. all the memcpy()s pick the smaller size of the
two).
Yes, in the vga source code, we also pick the smaller size of two. But
in other place, eg: vc_do_resize, copy the old_origin to new_origin, we
not do that. It also make bad access happen. it maybe CVE-2020-8647.
I think we should just assume the width/height maybe larger than the
default, not the screenbuf larger than vga_vram_size.
If not, any useful of the larger screenbuf?
Maybe used for scrolling?
The screenbuf just allocated with cols and rows, it can be save just one
screen?
vc_do_resize is the largest size which one screen can be shown?
If so, we can't set the screen to the resolution which more than it's
capability?
And you're changing the behaviour of the code when
'width % 2 && user' is true
