[PATCH] drm/amdgpu: reject mapping info for unmapped BOs

[Yousef Alhouseen <alhouseenyousef@gmail.com>]

AMDGPU_GEM_OP_GET_MAPPING_INFO looks up the BO's VM mapping and then
iterates the valid and invalid mapping lists unconditionally. A GEM BO can
be queried before it has been mapped into the file VM, in which case
amdgpu_vm_bo_find() returns NULL and the list walk dereferences it.

Return -ENOENT for an unmapped BO, matching the VA operation path that
already rejects missing BO-VA state before touching the mapping lists.

Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index 212c14d99..4b2699931 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -1087,6 +1087,12 @@ int amdgpu_gem_op_ioctl(struct drm_device *dev, void *data,
 		struct drm_amdgpu_gem_vm_entry *vm_entries;
 		struct amdgpu_bo_va_mapping *mapping;
 		int num_mappings = 0;
+
+		if (!bo_va) {
+			r = -ENOENT;
+			goto out_exec;
+		}
+
 		/*
 		 * num_entries is set as an input to the size of the user-allocated array of
 		 * drm_amdgpu_gem_vm_entry stored at args->value.
-- 
2.54.0