Patch "drm/amdkfd: Fix 'node' NULL check in 'svm_range_get_range_boundaries()'" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drm/amdkfd: Fix 'node' NULL check in 'svm_range_get_range_boundaries()'

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-amdkfd-fix-node-null-check-in-svm_range_get_rang.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit bce3fa23ac9bb606d6852405e6d008668801c497
Author: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
Date:   Tue Jan 9 16:57:26 2024 +0530

    drm/amdkfd: Fix 'node' NULL check in 'svm_range_get_range_boundaries()'
    
    [ Upstream commit d7a254fad873775ce6c32b77796c81e81e6b7f2e ]
    
    Range interval [start, last] is ordered by rb_tree, rb_prev, rb_next
    return value still needs NULL check, thus modified from "node" to "rb_node".
    
    Fixes the below:
    drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_svm.c:2691 svm_range_get_range_boundaries() warn: can 'node' even be NULL?
    
    Suggested-by: Philip Yang <Philip.Yang@xxxxxxx>
    Cc: Felix Kuehling <Felix.Kuehling@xxxxxxx>
    Cc: Christian König <christian.koenig@xxxxxxx>
    Cc: Alex Deucher <alexander.deucher@xxxxxxx>
    Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
    Reviewed-by: Felix Kuehling <felix.kuehling@xxxxxxx>
    Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index b51224a85a38..87e9ca65e58e 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2657,6 +2657,7 @@ svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
 {
 	struct vm_area_struct *vma;
 	struct interval_tree_node *node;
+	struct rb_node *rb_node;
 	unsigned long start_limit, end_limit;
 
 	vma = vma_lookup(p->mm, addr << PAGE_SHIFT);
@@ -2676,16 +2677,15 @@ svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
 	if (node) {
 		end_limit = min(end_limit, node->start);
 		/* Last range that ends before the fault address */
-		node = container_of(rb_prev(&node->rb),
-				    struct interval_tree_node, rb);
+		rb_node = rb_prev(&node->rb);
 	} else {
 		/* Last range must end before addr because
 		 * there was no range after addr
 		 */
-		node = container_of(rb_last(&p->svms.objects.rb_root),
-				    struct interval_tree_node, rb);
+		rb_node = rb_last(&p->svms.objects.rb_root);
 	}
-	if (node) {
+	if (rb_node) {
+		node = container_of(rb_node, struct interval_tree_node, rb);
 		if (node->last >= addr) {
 			WARN(1, "Overlap with prev node and page fault addr\n");
 			return -EFAULT;