Linux Kernel CVE-2026-43318

Primary mitigation is upgrading to patched kernel versions: 6.12.75 or later in the 6.12.x series, 6.18.16+ in the 6.18.x series, 6.19.6+ in the 6.19.x series, or kernel 7.0 final release. Organizations can obtain patches from upstream repositories at the git.kernel.org URLs listed in references or through distribution-specific security update channels (Red Hat RHSA, Ubuntu USN, SUSE/SLES updates). For environments unable to immediately patch, implement these compensating controls with noted trade-offs: (1) Disable DMA-BUF sharing for AMDGPU by setting kernel parameter amdgpu.noretry=1, which prevents cross-GPU buffer sharing but breaks applications requiring multi-GPU rendering like professional graphics workflows; (2) Force single-GPU operation by disabling secondary AMD cards in BIOS or blacklisting the amdgpu module for specific PCI devices using modprobe configuration, eliminating multi-GPU capability entirely; (3) Enable P2P PCI access in BIOS if supported by hardware platform and verify with lspci, which may resolve the race condition by changing buffer migration behavior but requires compatible motherboard/CPU. Each workaround degrades GPU functionality and should only be temporary pending kernel upgrade. No application-layer or firewall-based mitigations are effective against this kernel driver bug.