The "alloc_size" calculation can overflow leading to memory corruption.
Reported-by: Ilja Van Sprundel <ivansprundel at ioactive.com>
Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
---
The amdgpu_asic_read_register() functions seem likely to be slow. They
iterate through all the registers to find the correct register to read.
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
index 2236793..8c735f5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -390,7 +390,7 @@ static int amdgpu_info_ioctl(struct drm_device *dev, void
*data, struct drm_file
min((size_t)size, sizeof(vram_gtt))) ?
-EFAULT : 0;
}
case AMDGPU_INFO_READ_MMR_REG: {
- unsigned n, alloc_size = info->read_mmr_reg.count * 4;
+ unsigned n, alloc_size;
uint32_t *regs;
unsigned se_num = (info->read_mmr_reg.instance >>
AMDGPU_INFO_MMR_SE_INDEX_SHIFT) &
@@ -406,9 +406,10 @@ static int amdgpu_info_ioctl(struct drm_device *dev, void
*data, struct drm_file
if (sh_num == AMDGPU_INFO_MMR_SH_INDEX_MASK)
sh_num = 0xffffffff;
- regs = kmalloc(alloc_size, GFP_KERNEL);
+ regs = kmalloc_array(info->read_mmr_reg.count, sizeof(*regs),
GFP_KERNEL);
if (!regs)
return -ENOMEM;
+ alloc_size = info->read_mmr_reg.count * sizeof(*regs);
for (i = 0; i < info->read_mmr_reg.count; i++)
if (amdgpu_asic_read_register(adev, se_num, sh_num,
