drm/amdgpu: add upper bound check on user inputs in signal ioctl

Huge input values in amdgpu_userq_signal_ioctl can lead to a OOM and
could be exploited.

So check these input value against AMDGPU_USERQ_MAX_HANDLES
which is big enough value for genuine use cases and could
potentially avoid OOM.

Signed-off-by: Sunil Khatri <sunil.khatri@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit be267e15f99bc97cbe202cd556717797cdcf79a5)
Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
index d972dc46f5a8956a5150df692c383fa55aba64d8..c5f5af20af756f89b8ba3ec4bfeab3b660712195 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
@@ -35,6 +35,8 @@
 static const struct dma_fence_ops amdgpu_userq_fence_ops;
 static struct kmem_cache *amdgpu_userq_fence_slab;
 
+#define AMDGPU_USERQ_MAX_HANDLES       (1U << 16)
+
 int amdgpu_userq_fence_slab_init(void)
 {
        amdgpu_userq_fence_slab = kmem_cache_create("amdgpu_userq_fence",
@@ -478,6 +480,11 @@ int amdgpu_userq_signal_ioctl(struct drm_device *dev, void *data,
        if (!amdgpu_userq_enabled(dev))
                return -ENOTSUPP;
 
+       if (args->num_syncobj_handles > AMDGPU_USERQ_MAX_HANDLES ||
+           args->num_bo_write_handles > AMDGPU_USERQ_MAX_HANDLES ||
+           args->num_bo_read_handles > AMDGPU_USERQ_MAX_HANDLES)
+               return -EINVAL;
+
        num_syncobj_handles = args->num_syncobj_handles;
        syncobj_handles = memdup_user(u64_to_user_ptr(args->syncobj_handles),
                                      size_mul(sizeof(u32), num_syncobj_handles));