If randrp->palette_size is zero, the memcpy() path can read past the
end of the randr_crtc's gammaRed/Green/Blue tables if the hw crtc's
gamma_size is greater than the randr_crtc's gammaSize.
Avoid this by clamping the to-be-copied size to the smaller of both
sizes.
Note that during regular server startup, the memcpy() path is only
taken initially twice, but then a suitable palette is created for
use during a session. Therefore during an actual running X-Session,
the xf86RandR12CrtcComputeGamma() will be used, which makes sure that
data is properly up- or down-sampled for mismatching source and
target crtc gamma sizes.
This should avoid reading past randr_crtc gamma memory for gpu's
with big crtc->gamma_size, e.g., AMD/MALI/KOMEDA 4096 slots, or
Intel Icelake and later with 262145 slots.
Tested against modesetting-ddx and amdgpu-ddx under screen color
depth 24 (8 bpc) and 30 (10 bpc) to make sure that clamping happens
properly.
This is an alternative fix for the one attempted in commit
|
||
|---|---|---|
| .. | ||
| kdrive | ||
| vfb | ||
| xfree86 | ||
| xnest | ||
| xquartz | ||
| xwayland | ||
| xwin | ||
| Makefile.am | ||
| meson.build | ||