From: Jon Doron <jond@wiz.io> mainline inclusion from mainline-v6.19-rc8 commit 8b1ecc9377bc641533cd9e76dfa3aee3cd04a007 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/13713 CVE: CVE-2026-23163 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- 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) Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3814 Fixes: dd299441654f ("drm/amdgpu: Rework retry fault removal") Reviewed-by: Timur Kristóf <timur.kristof@gmail.com> Reviewed-by: Philip Yang <Philip.Yang@amd.com> Signed-off-by: Jon Doron <jond@wiz.io> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> (cherry picked from commit 6ce8d536c80aa1f059e82184f0d1994436b1d526) Cc: stable@vger.kernel.org Signed-off-by: Zhang Hongtao <zhanghongtao35@huawei.com> --- drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c index 9b225acdcf974..3c24637f3d6e9 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c @@ -454,8 +454,13 @@ void amdgpu_gmc_filter_faults_remove(struct amdgpu_device *adev, uint64_t addr, if (adev->irq.retry_cam_enabled) return; + else if (adev->irq.ih1.ring_size) + ih = &adev->irq.ih1; + else if (adev->irq.ih_soft.enabled) + ih = &adev->irq.ih_soft; + else + return; - ih = &adev->irq.ih1; /* Get the WPTR of the last entry in IH ring */ last_wptr = amdgpu_ih_get_wptr(adev, ih); /* Order wptr with ring data. */ -- 2.43.0