[PATCH v2 0/3] drm/msm/gem: A couple VM_BIND fixes

[PATCH v2 0/3] drm/msm/gem: A couple VM_BIND fixes

[Rob Clark]

Fix possible overflow in range check, and disallow passing BOs table to
GEM_SUBMIT for VM_BIND contexts.

v2:
- Also check that range/obj_offset are not greater than SIZE_MAX.  It
  doesn't matter currently, but would if an armv7 system ever added
  support for per-process pgtables and VM_BIND.
- Add patch to fix handle-dereference in idr_find() error path
- Link to v1: https://lore.kernel.org/all/20261101174911.25184-1-robin.clark@oss.qualcomm.com/

Rob Clark (3):
  drm/msm/gem: Fix VM_BIND range check
  drm/msm/gem: Disallow nr_bos for VM_BIND contexts
  drm/msm/gem: Decrement loop idx if handle lookup fails

 drivers/gpu/drm/msm/msm_gem_submit.c | 5 ++++-
 drivers/gpu/drm/msm/msm_gem_vma.c    | 7 ++++---
 2 files changed, 8 insertions(+), 4 deletions(-)

-- 
2.56.0

[PATCH v2 1/3] drm/msm/gem: Fix VM_BIND range check

[Rob Clark]

Use size_add() to guard against overflow.

Reported-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Fixes: 3a3bef68a6c1 ("drm/msm: Fix missing VM_BIND offset/range validation")
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/msm_gem_vma.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem_vma.c b/drivers/gpu/drm/msm/msm_gem_vma.c
index f687a629629d..922285537dee 100644
--- a/drivers/gpu/drm/msm/msm_gem_vma.c
+++ b/drivers/gpu/drm/msm/msm_gem_vma.c
@@ -1012,10 +1012,10 @@ lookup_op(struct msm_vm_bind_job *job, const struct drm_msm_vm_bind_op *op)
 	if (invalid_alignment(op->iova))
 		ret = UERR(EINVAL, dev, "invalid address: %016llx\n", op->iova);
 
-	if (invalid_alignment(op->obj_offset))
+	if (invalid_alignment(op->obj_offset) || (op->obj_offset > SIZE_MAX))
 		ret = UERR(EINVAL, dev, "invalid bo_offset: %016llx\n", op->obj_offset);
 
-	if (invalid_alignment(op->range))
+	if (invalid_alignment(op->range) || (op->range > SIZE_MAX))
 		ret = UERR(EINVAL, dev, "invalid range: %016llx\n", op->range);
 
 	if (!drm_gpuvm_range_valid(job->vm, op->iova, op->range))
@@ -1118,7 +1118,7 @@ vm_bind_job_lookup_ops(struct msm_vm_bind_job *job, struct drm_msm_vm_bind *args
 		op->obj = obj;
 		cnt++;
 
-		if ((op->range + op->obj_offset) > obj->size) {
+		if (size_add(op->range, op->obj_offset) > obj->size) {
 			ret = UERR(EINVAL, dev, "invalid range: %016llx + %016llx > %016zx\n",
 				   op->range, op->obj_offset, obj->size);
 			goto out_unlock;
-- 
2.56.0

[PATCH v2 2/3] drm/msm/gem: Disallow nr_bos for VM_BIND contexts

[Rob Clark]

If using VM_BIND, it is invalid to attach BOs to a GEM_SUBMIT ioctl.
Only the VM_BIND ioctl should be used for binding objects.

Fixes: 2e6a8a1fe2b2 ("drm/msm: Add VM_BIND ioctl")
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/msm_gem_submit.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index ff6cf39587c9..b558d07ed2b6 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -272,7 +272,7 @@ static int submit_lock_objects_vmbind(struct msm_gem_submit *submit)
 	struct drm_exec *exec = &submit->exec;
 	int ret = 0;
 
-	drm_exec_init(&submit->exec, flags, submit->nr_bos);
+	drm_exec_init(&submit->exec, flags, 0);
 	submit->has_exec = true;
 
 	drm_exec_until_all_locked (&submit->exec) {
@@ -589,6 +589,9 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 			return -EINVAL;
 	}
 
+	if (msm_context_is_vmbind(ctx) && args->nr_bos)
+		return UERR(EINVAL, dev, "invalid nr_bos, must be zero for VM_BIND contexts");
+
 	queue = msm_submitqueue_get(ctx, args->queueid);
 	if (!queue)
 		return -ENOENT;
-- 
2.56.0

[PATCH v2 3/3] drm/msm/gem: Decrement loop idx if handle lookup fails

[Rob Clark]

In the out_unlock unlock loop, we should skip the op which still has the
gem handle instead of gem obj ptr.

Fixes: 2e6a8a1fe2b2 ("drm/msm: Add VM_BIND ioctl")
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/msm_gem_vma.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/msm/msm_gem_vma.c b/drivers/gpu/drm/msm/msm_gem_vma.c
index 922285537dee..4413db0644a2 100644
--- a/drivers/gpu/drm/msm/msm_gem_vma.c
+++ b/drivers/gpu/drm/msm/msm_gem_vma.c
@@ -1110,6 +1110,7 @@ vm_bind_job_lookup_ops(struct msm_vm_bind_job *job, struct drm_msm_vm_bind *args
 		obj = idr_find(&file->object_idr, op->handle);
 		if (!obj) {
 			ret = UERR(EINVAL, dev, "invalid handle %u at index %u\n", op->handle, i);
+			i--;
 			goto out_unlock;
 		}
 
-- 
2.56.0