In the Linux kernel, the following vulnerability has been resolved:
bpf: Check pointer type for all atomic RMW paths
Atomic RMW verification records an instruction pointer type only when the
current destination is PTR_TO_ARENA. A second path can therefore reach the
same instruction with an ordinary pointer without comparing it against the
saved arena type. The post-verification fixup uses the saved type to rewrite the instruction
to BPF_PROBE_ATOMIC for every path.
Record the actual destination type for all atomic RMW paths so the existing mismatch check rejects incompatible uses of one instruction.
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