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 <lijo.lazar@amd.com>
Signed-off-by: Asad Kamal <asad.kamal@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit bf21af331ebf72d0935fd70c73192414a422c03a)
CC: stable@vger.kernel.org

0 files changed, 0 insertions, 0 deletions