[PATCH AUTOSEL 5.12 42/49] drm/amdgpu: refine amdgpu_fru_get_product_info

Sasha Levin
2021-06-07T16:15:21Z

From: Jiansong Chen <Jiansong.Chen@amd.com>

[ Upstream commit 5cfc912582e13b05d71fb7acc4ec69ddfa9af320 ]

1. eliminate potential array index out of bounds.
2. return meaningful value for failure.

Signed-off-by: Jiansong Chen <Jiansong.Chen@amd.com>
Reviewed-by: Jack Gui <Jack.Gui@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c | 42 ++++++++++---------
1 file changed, 23 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c
index 8f4a8f8d8146..39b6c6bfab45 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c
@@ -101,7 +101,8 @@ static int amdgpu_fru_read_eeprom(struct amdgpu_device *adev, uint32_t addrptr,
int amdgpu_fru_get_product_info(struct amdgpu_device *adev)
{
unsigned char buff[34];
- int addrptr = 0, size = 0;
+ int addrptr, size;
+ int len;

if (!is_fru_eeprom_supported(adev))
return 0;
@@ -109,7 +110,7 @@ int amdgpu_fru_get_product_info(struct amdgpu_device *adev)
/* If algo exists, it means that the i2c_adapter's initialized */
if (!adev->pm.smu_i2c.algo) {
DRM_WARN("Cannot access FRU, EEPROM accessor not initialized");
- return 0;
+ return -ENODEV;
}

/* There's a lot of repetition here. This is due to the FRU having
@@ -128,7 +129,7 @@ int amdgpu_fru_get_product_info(struct amdgpu_device *adev)
size = amdgpu_fru_read_eeprom(adev, addrptr, buff);
if (size < 1) {
DRM_ERROR("Failed to read FRU Manufacturer, ret:%d", size);
- return size;
+ return -EINVAL;
}

/* Increment the addrptr by the size of the field, and 1 due to the
@@ -138,43 +139,45 @@ int amdgpu_fru_get_product_info(struct amdgpu_device *adev)
size = amdgpu_fru_read_eeprom(adev, addrptr, buff);
if (size < 1) {
DRM_ERROR("Failed to read FRU product name, ret:%d", size);
- return size;
+ return -EINVAL;
}

+ len = size;
/* Product name should only be 32 characters. Any more,
* and something could be wrong. Cap it at 32 to be safe
*/
- if (size > 32) {
+ if (len >= sizeof(adev->product_name)) {
DRM_WARN("FRU Product Number is larger than 32 characters. This is likely a mistake");
- size = 32;
+ len = sizeof(adev->product_name) - 1;
}
/* Start at 2 due to buff using fields 0 and 1 for the address */
- memcpy(adev->product_name, &buff[2], size);
- adev->product_name[size] = '\0';
+ memcpy(adev->product_name, &buff[2], len);
+ adev->product_name[len] = '\0';

addrptr += size + 1;
size = amdgpu_fru_read_eeprom(adev, addrptr, buff);
if (size < 1) {
DRM_ERROR("Failed to read FRU product number, ret:%d", size);
- return size;
+ return -EINVAL;
}

+ len = size;
/* Product number should only be 16 characters. Any more,
* and something could be wrong. Cap it at 16 to be safe
*/
- if (size > 16) {
+ if (len >= sizeof(adev->product_number)) {
DRM_WARN("FRU Product Number is larger than 16 characters. This is likely a mistake");
- size = 16;
+ len = sizeof(adev->product_number) - 1;
}
- memcpy(adev->product_number, &buff[2], size);
- adev->product_number[size] = '\0';
+ memcpy(adev->product_number, &buff[2], len);
+ adev->product_number[len] = '\0';

addrptr += size + 1;
size = amdgpu_fru_read_eeprom(adev, addrptr, buff);

if (size < 1) {
DRM_ERROR("Failed to read FRU product version, ret:%d", size);
- return size;
+ return -EINVAL;
}

addrptr += size + 1;
@@ -182,18 +185,19 @@ int amdgpu_fru_get_product_info(struct amdgpu_device *adev)

if (size < 1) {
DRM_ERROR("Failed to read FRU serial number, ret:%d", size);
- return size;
+ return -EINVAL;
}

+ len = size;
/* Serial number should only be 16 characters. Any more,
* and something could be wrong. Cap it at 16 to be safe
*/
- if (size > 16) {
+ if (len >= sizeof(adev->serial)) {
DRM_WARN("FRU Serial Number is larger than 16 characters. This is likely a mistake");
- size = 16;
+ len = sizeof(adev->serial) - 1;
}
- memcpy(adev->serial, &buff[2], size);
- adev->serial[size] = '\0';
+ memcpy(adev->serial, &buff[2], len);
+ adev->serial[len] = '\0';

return 0;
}
--
2.30.2