CVE-2026-23163: linux kernel vulnerability

What is known

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: fix NULL pointer dereference in amdgpu_gmc_filter_faults_remove On APUs such as Raven and Renoir (GC 9.1.0, 9.2.2, 9.3.0), the ih1 and ih2 interrupt ring buffers are not initialized. This is by design, as these secondary IH rings are only available on discrete GPUs. See vega10_ih_sw_init() which explicitly skips ih1/ih2 initialization when AMD_IS_APU is set. However, amdgpu_gmc_filter_faults_remove() unconditionally uses ih1 to get the timestamp of the last interrupt entry. When retry faults are enabled on APUs (noretry=0), this function is called from the SVM page fault recovery path, resulting in a NULL pointer dereference when amdgpu_ih_decode_iv_ts_helper() attempts to access ih->ring[]. The crash manifests as: BUG: kernel NULL pointer dereference, address: 0000000000000004 RIP: 0010:amdgpu_ih_decode_iv_ts_helper+0x22/0x40 [amdgpu] Call Trace: amdgpu_gmc_filter_faults_remove+0x60/0x130 [amdgpu] svm_range_restore_pages+0xae5/0x11c0 [amdgpu] amdgpu_vm_handle_fault+0xc8/0x340 [amdgpu] gmc_v9_0_process_interrupt+0x191/0x220 [amdgpu] amdgpu_irq_dispatch+0xed/0x2c0 [amdgpu] amdgpu_ih_process+0x84/0x100 [amdgpu] This issue was exposed by commit 1446226d32a4 ("drm/amdgpu: Remove GC HW IP 9.3.0 from noretry=1") which changed the default for Renoir APU from noretry=1 to noretry=0, enabling retry fault handling and thus exercising the buggy code path. Fix this by adding a check for ih1.ring_size before attempting to use it. Also restore the soft_ih support from commit dd299441654f ("drm/amdgpu: Rework retry fault removal"). This is needed if the hardware doesn't support secondary HW IH rings. v2: additional updates (Alex) (cherry picked from commit 6ce8d536c80aa1f059e82184f0d1994436b1d526)

Business impact

Successful exploitation of CVE-2026-23163, a medium vulnerability (CVSS 5.5) affecting linux kernel, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether linux kernel is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
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