From: Asad Kamal Date: Fri, 5 Jun 2026 15:44:08 +0000 (+0800) Subject: drm/amdgpu/gfx: fix cleaner shader IB buffer overflow X-Git-Tag: v7.2-rc1~10^2~1^2~23 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3e864bf2a32a1cbdf1e0f9c5a5a4176e8575f4a3;p=thirdparty%2Fkernel%2Flinux.git drm/amdgpu/gfx: fix cleaner shader IB buffer overflow The cleaner shader sysfs path allocates a 16-dword (64 byte) IB but incorrectly fills (align_mask + 1) dwords. On GFX rings align_mask is 0xff, so the loop wrote 256 dwords into a 64-byte buffer, causing a kernel page fault. The IB only needs to be a minimal NOP shell to schedule the job; the cleaner shader itself is emitted on the ring via emit_cleaner_shader(). Fill 16 dwords to match the allocation. v2: Use ib_size_dw variable (Lijo) Fixes: d361ad5d2fc0 ("drm/amdgpu: Add sysfs interface for running cleaner shader") Suggested-by: Lijo Lazar Signed-off-by: Asad Kamal Reviewed-by: Lijo Lazar Signed-off-by: Alex Deucher (cherry picked from commit bf21af331ebf72d0935fd70c73192414a422c03a) CC: stable@vger.kernel.org --- diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c index 1e190fb54a977..85372af1216d0 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c @@ -1664,12 +1664,13 @@ static int amdgpu_gfx_run_cleaner_shader_job(struct amdgpu_ring *ring) struct amdgpu_device *adev = ring->adev; struct drm_gpu_scheduler *sched = &ring->sched; struct drm_sched_entity entity; + unsigned int ib_size_dw = 16; static atomic_t counter; struct dma_fence *f; struct amdgpu_job *job; struct amdgpu_ib *ib; void *owner; - int i, r; + int r; /* Initialize the scheduler entity */ r = drm_sched_entity_init(&entity, DRM_SCHED_PRIORITY_NORMAL, @@ -1687,7 +1688,7 @@ static int amdgpu_gfx_run_cleaner_shader_job(struct amdgpu_ring *ring) owner = (void *)(unsigned long)atomic_inc_return(&counter); r = amdgpu_job_alloc_with_ib(ring->adev, &entity, owner, - 64, 0, &job, + ib_size_dw * sizeof(uint32_t), 0, &job, AMDGPU_KERNEL_JOB_ID_CLEANER_SHADER); if (r) goto err; @@ -1697,9 +1698,8 @@ static int amdgpu_gfx_run_cleaner_shader_job(struct amdgpu_ring *ring) job->run_cleaner_shader = true; ib = &job->ibs[0]; - for (i = 0; i <= ring->funcs->align_mask; ++i) - ib->ptr[i] = ring->funcs->nop; - ib->length_dw = ring->funcs->align_mask + 1; + memset32(ib->ptr, ring->funcs->nop, ib_size_dw); + ib->length_dw = ib_size_dw; f = amdgpu_job_submit(job);