In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix divide-by-zero in calculate_mcache_setting on zero viewport
If a plane reaches calculate_mcache_setting with a zero-area viewport,
calculate_mcache_setting exits early with num_mcaches == 0 and
mvmpg_width/height == 0. This will cause a divide-by-zero panic and can
also cause an underflow on num_mcaches. Fix this by changing calculate_mcache_setting to bool and adding guards
after each calculate_mcache_row_bytes call.
If num_mcaches or
mvmpg_width/height is zero, return a false. Callers will propagate the
failure as a rejected mode, which prevents the panic.
(cherry picked from commit 29c0f7c655f47bcbd575ff75e58480df6ec3c9da)
Attack Parameters
Attack Vector
Local
Requires local access
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1