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From b7a11dbe0025b10058bba25f70afa1e05c101cba Mon Sep 17 00:00:00 2001
From: Evan Quan <evan.quan@amd.com>
Date: Mon, 16 Oct 2017 16:51:28 +0800
Subject: [PATCH 2048/4131] drm/amdgpu/psp: prevent page fault by checking
write_frame address(v3)
- 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
Change-Id: If3b79428b32ffab57b4e75f9c20c2b2d7e600223
Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
---
drivers/gpu/drm/amd/amdgpu/psp_v10_0.c | 16 ++++++++++++++--
drivers/gpu/drm/amd/amdgpu/psp_v3_1.c | 16 ++++++++++++++--
2 files changed, 28 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 d2283b6..410dd78 100644
--- a/drivers/gpu/drm/amd/amdgpu/psp_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/psp_v10_0.c
@@ -260,6 +260,9 @@ 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;
@@ -269,9 +272,18 @@ 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 = %x; ring_buffer_end = %x; write_frame = %x\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..d217050 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 +381,18 @@ 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 = %x; ring_buffer_end = %x; write_frame = %x\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
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