From 4694257e7d4757fedaa8dcd18bb5ff52e76a2765 Mon Sep 17 00:00:00 2001 From: Evan Quan Date: Mon, 16 Oct 2017 16:51:28 +0800 Subject: [PATCH] drm/amdgpu/psp: prevent page fault by checking write_frame address(v4) - Prevent a possible buffer overflow when updating the ring buffer by bounds checking the command frame against the available space in the ring buffer. v2: update the ring_buffer_end address v3: update the commit log v4: squash in print fix (Michel) Signed-off-by: Evan Quan Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/psp_v10_0.c | 14 ++++++++++++-- drivers/gpu/drm/amd/amdgpu/psp_v3_1.c | 14 ++++++++++++-- 2 files changed, 24 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/psp_v10_0.c b/drivers/gpu/drm/amd/amdgpu/psp_v10_0.c index dea7c909..4e20d91 100644 --- a/drivers/gpu/drm/amd/amdgpu/psp_v10_0.c +++ b/drivers/gpu/drm/amd/amdgpu/psp_v10_0.c @@ -257,6 +257,9 @@ int psp_v10_0_cmd_submit(struct psp_context *psp, unsigned int psp_write_ptr_reg = 0; struct psp_gfx_rb_frame * write_frame = psp->km_ring.ring_mem; struct psp_ring *ring = &psp->km_ring; + struct psp_gfx_rb_frame *ring_buffer_start = ring->ring_mem; + struct psp_gfx_rb_frame *ring_buffer_end = ring_buffer_start + + ring->ring_size / sizeof(struct psp_gfx_rb_frame) - 1; struct amdgpu_device *adev = psp->adev; uint32_t ring_size_dw = ring->ring_size / 4; uint32_t rb_frame_size_dw = sizeof(struct psp_gfx_rb_frame) / 4; @@ -266,9 +269,16 @@ int psp_v10_0_cmd_submit(struct psp_context *psp, /* Update KM RB frame pointer to new frame */ if ((psp_write_ptr_reg % ring_size_dw) == 0) - write_frame = ring->ring_mem; + write_frame = ring_buffer_start; else - write_frame = ring->ring_mem + (psp_write_ptr_reg / rb_frame_size_dw); + write_frame = ring_buffer_start + (psp_write_ptr_reg / rb_frame_size_dw); + /* Check invalid write_frame ptr address */ + if ((write_frame < ring_buffer_start) || (ring_buffer_end < write_frame)) { + DRM_ERROR("ring_buffer_start = %p; ring_buffer_end = %p; write_frame = %p\n", + ring_buffer_start, ring_buffer_end, write_frame); + DRM_ERROR("write_frame is pointing to address out of bounds\n"); + return -EINVAL; + } /* Initialize KM RB frame */ memset(write_frame, 0, sizeof(struct psp_gfx_rb_frame)); diff --git a/drivers/gpu/drm/amd/amdgpu/psp_v3_1.c b/drivers/gpu/drm/amd/amdgpu/psp_v3_1.c index cee5c39..c7bcfe8 100644 --- a/drivers/gpu/drm/amd/amdgpu/psp_v3_1.c +++ b/drivers/gpu/drm/amd/amdgpu/psp_v3_1.c @@ -367,6 +367,9 @@ int psp_v3_1_cmd_submit(struct psp_context *psp, unsigned int psp_write_ptr_reg = 0; struct psp_gfx_rb_frame * write_frame = psp->km_ring.ring_mem; struct psp_ring *ring = &psp->km_ring; + struct psp_gfx_rb_frame *ring_buffer_start = ring->ring_mem; + struct psp_gfx_rb_frame *ring_buffer_end = ring_buffer_start + + ring->ring_size / sizeof(struct psp_gfx_rb_frame) - 1; struct amdgpu_device *adev = psp->adev; uint32_t ring_size_dw = ring->ring_size / 4; uint32_t rb_frame_size_dw = sizeof(struct psp_gfx_rb_frame) / 4; @@ -378,9 +381,16 @@ int psp_v3_1_cmd_submit(struct psp_context *psp, /* write_frame ptr increments by size of rb_frame in bytes */ /* psp_write_ptr_reg increments by size of rb_frame in DWORDs */ if ((psp_write_ptr_reg % ring_size_dw) == 0) - write_frame = ring->ring_mem; + write_frame = ring_buffer_start; else - write_frame = ring->ring_mem + (psp_write_ptr_reg / rb_frame_size_dw); + write_frame = ring_buffer_start + (psp_write_ptr_reg / rb_frame_size_dw); + /* Check invalid write_frame ptr address */ + if ((write_frame < ring_buffer_start) || (ring_buffer_end < write_frame)) { + DRM_ERROR("ring_buffer_start = %p; ring_buffer_end = %p; write_frame = %p\n", + ring_buffer_start, ring_buffer_end, write_frame); + DRM_ERROR("write_frame is pointing to address out of bounds\n"); + return -EINVAL; + } /* Initialize KM RB frame */ memset(write_frame, 0, sizeof(struct psp_gfx_rb_frame)); -- 2.7.4