[PATCH 4.19 105/125] drm/amdgpu: Fix buffer overflow in INFO ioctl

Greg Kroah-Hartman
2020-09-01T16:52:56Z

From: Alex Deucher <alexander.deucher@amd.com>

commit b5b97cab55eb71daba3283c8b1d2cce456d511a1 upstream.

The values for "se_num" and "sh_num" come from the user in the ioctl.
They can be in the 0-255 range but if they're more than
AMDGPU_GFX_MAX_SE (4) or AMDGPU_GFX_MAX_SH_PER_SE (2) then it results in
an out of bounds read.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -524,8 +524,12 @@ static int amdgpu_info_ioctl(struct drm_
* in the bitfields */
if (se_num == AMDGPU_INFO_MMR_SE_INDEX_MASK)
se_num = 0xffffffff;
+ else if (se_num >= AMDGPU_GFX_MAX_SE)
+ return -EINVAL;
if (sh_num == AMDGPU_INFO_MMR_SH_INDEX_MASK)
sh_num = 0xffffffff;
+ else if (sh_num >= AMDGPU_GFX_MAX_SH_PER_SE)
+ return -EINVAL;

if (info->read_mmr_reg.count > 128)
return -EINVAL;