Commit 90ef1dcb authored by Srinivasan Shanmugam's avatar Srinivasan Shanmugam Committed by Alex Deucher
Browse files

drm/amdgpu: Fix pointer casts when reading dynamic region sizes 



The function amdgpu_virt_get_dynamic_data_info() writes a 64-bit size
value.  In two places (amdgpu_bios.c and amdgpu_discovery.c), the code
passed the address of a smaller variable by casting it to u64 *, which
is unsafe.

This could make the function write more bytes than the smaller variable
can hold, possibly overwriting nearby memory. Reported by static
analysis tools.

v2: Dynamic region size comes from the host (SR-IOV setup) and is always
fixed to 5 MB. (Lijo/Ellen)

5 MB easily fits inside a 32-bit value, so using a 64-bit type is not
needed. It also avoids extra type casts

Fixes: b4a8fcc7 ("drm/amdgpu: Add logic for VF ipd and VF bios to init from dynamic crit_region offsets")
Reported by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Ellen Pan <yunru.pan@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarSrinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: default avatarLijo Lazar <lijo.lazar@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 84564d29

drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c

+2 −2
Original line number Diff line number Diff line
@@ -103,7 +103,7 @@ static bool amdgpu_read_bios_from_vram(struct amdgpu_device *adev) 
{

	uint8_t __iomem *bios = NULL;

	resource_size_t vram_base;

	resource_size_t size = 256 * 1024; /* ??? */

	u32 size = 256U * 1024U; /* ??? */



	if (!(adev->flags & AMD_IS_APU))

		if (amdgpu_device_need_post(adev))
@@ -126,7 +126,7 @@ static bool amdgpu_read_bios_from_vram(struct amdgpu_device *adev) 
	 */

	if (amdgpu_sriov_vf(adev) && adev->virt.is_dynamic_crit_regn_enabled) {

		if (amdgpu_virt_get_dynamic_data_info(adev,

				AMD_SRIOV_MSG_VBIOS_IMG_TABLE_ID, adev->bios, (uint64_t *)&size)) {

				AMD_SRIOV_MSG_VBIOS_IMG_TABLE_ID, adev->bios, &size)) {

			amdgpu_bios_release(adev);

			return false;

		}

drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c

+1 −1
Original line number Diff line number Diff line
@@ -311,7 +311,7 @@ static int amdgpu_discovery_read_binary_from_mem(struct amdgpu_device *adev, 
			 */

			if (amdgpu_virt_get_dynamic_data_info(adev,

						AMD_SRIOV_MSG_IPD_TABLE_ID, binary,

						(uint64_t *)&adev->discovery.size)) {

						&adev->discovery.size)) {

				dev_err(adev->dev,

						"failed to read discovery info from dynamic critical region.");

				ret = -EINVAL;

drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c

+1 −1
Original line number Diff line number Diff line
@@ -1102,7 +1102,7 @@ int amdgpu_virt_init_critical_region(struct amdgpu_device *adev) 
}



int amdgpu_virt_get_dynamic_data_info(struct amdgpu_device *adev,

	int data_id, uint8_t *binary, uint64_t *size)

	int data_id, uint8_t *binary, u32 *size)

{

	uint32_t data_offset = 0;

	uint32_t data_size = 0;

drivers/gpu/drm/amd/amdgpu/amdgpu_virt.h

+1 −1
Original line number Diff line number Diff line
@@ -443,7 +443,7 @@ void amdgpu_virt_init(struct amdgpu_device *adev); 


int amdgpu_virt_init_critical_region(struct amdgpu_device *adev);

int amdgpu_virt_get_dynamic_data_info(struct amdgpu_device *adev,

	int data_id, uint8_t *binary, uint64_t *size);

	int data_id, uint8_t *binary, u32 *size);



bool amdgpu_virt_can_access_debugfs(struct amdgpu_device *adev);

int amdgpu_virt_enable_access_debugfs(struct amdgpu_device *adev);