Commit 98a46a40 authored by Dan Carpenter's avatar Dan Carpenter Committed by Alex Deucher
Browse files

drm/amdgpu: Fix integer overflow issues in amdgpu_userq_fence.c 



This patch only affects 32bit systems.  There are several integer
overflows bugs here but only the "sizeof(u32) * num_syncobj"
multiplication is a problem at runtime.  (The last lines of this patch).

These variables are u32 variables that come from the user.  The issue
is the multiplications can overflow leading to us allocating a smaller
buffer than intended.  For the first couple integer overflows, the
syncobj_handles = memdup_user() allocation is immediately followed by
a kmalloc_array():

	syncobj = kmalloc_array(num_syncobj_handles, sizeof(*syncobj), GFP_KERNEL);

In that situation the kmalloc_array() works as a bounds check and we
haven't accessed the syncobj_handlesp[] array yet so the integer overflow
is harmless.

But the "num_syncobj" multiplication doesn't have that and the integer
overflow could lead to an out of bounds access.

Fixes: a292fdec ("drm/amdgpu: Implement userqueue signal/wait IOCTL")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 5cccf10f

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

+4 −4
Original line number Diff line number Diff line
@@ -430,7 +430,7 @@ int amdgpu_userq_signal_ioctl(struct drm_device *dev, void *data, 


	num_syncobj_handles = args->num_syncobj_handles;

	syncobj_handles = memdup_user(u64_to_user_ptr(args->syncobj_handles),

				      sizeof(u32) * num_syncobj_handles);

				      size_mul(sizeof(u32), num_syncobj_handles));

	if (IS_ERR(syncobj_handles))

		return PTR_ERR(syncobj_handles);
@@ -612,13 +612,13 @@ int amdgpu_userq_wait_ioctl(struct drm_device *dev, void *data, 


	num_read_bo_handles = wait_info->num_bo_read_handles;

	bo_handles_read = memdup_user(u64_to_user_ptr(wait_info->bo_read_handles),

				      sizeof(u32) * num_read_bo_handles);

				      size_mul(sizeof(u32), num_read_bo_handles));

	if (IS_ERR(bo_handles_read))

		return PTR_ERR(bo_handles_read);



	num_write_bo_handles = wait_info->num_bo_write_handles;

	bo_handles_write = memdup_user(u64_to_user_ptr(wait_info->bo_write_handles),

				       sizeof(u32) * num_write_bo_handles);

				       size_mul(sizeof(u32), num_write_bo_handles));

	if (IS_ERR(bo_handles_write)) {

		r = PTR_ERR(bo_handles_write);

		goto free_bo_handles_read;
@@ -626,7 +626,7 @@ int amdgpu_userq_wait_ioctl(struct drm_device *dev, void *data, 


	num_syncobj = wait_info->num_syncobj_handles;

	syncobj_handles = memdup_user(u64_to_user_ptr(wait_info->syncobj_handles),

				      sizeof(u32) * num_syncobj);

				      size_mul(sizeof(u32), num_syncobj));

	if (IS_ERR(syncobj_handles)) {

		r = PTR_ERR(syncobj_handles);

		goto free_bo_handles_write;