Fixed an instance of undefined behaviour in tools::activate which could access invalid values representing child pointers

Idclip · Idclip · commit 669fbabba53e · 2023-12-15T14:58:35.000+13:00
Signed-off-by: Nick Avramoussis &lt;4256455+Idclip@users.noreply.github.com&gt;
diff --git a/openvdb/openvdb/tools/Activate.h b/openvdb/openvdb/tools/Activate.h
@@ -87,6 +87,10 @@ struct ActivateOp
         // only iterate if there are inactive tiles
         if (!node.isValueMaskOn()) {
             for (auto it = node.beginValueOff(); it; ++it) {
+                // Skip child nodes, they'll be processed separately
+                // (InteralNode ValueOff iterators don't automatically
+                // skip these).
+                if (node.isChildMaskOn(it.pos())) continue;
                 if (check(*it))     it.setValueOn(/*on=*/true);
             }
         }
diff --git a/pendingchanges/ubsan.txt b/pendingchanges/ubsan.txt
@@ -0,0 +1,3 @@
+OpenVDB:
+	- Bug Fixes::
+		- Fixed an occurance of undefined behaviour in tools::activate (though this would typically not have manifested with any unintended behaviour)

Original file line number	Diff line number	Diff line change
`@@ -87,6 +87,10 @@ struct ActivateOp`
`87`	`87`	`// only iterate if there are inactive tiles`
`88`	`88`	`if (!node.isValueMaskOn()) {`
`89`	`89`	`for (auto it = node.beginValueOff(); it; ++it) {`
	`90`	`+ // Skip child nodes, they'll be processed separately`
	`91`	`+ // (InteralNode ValueOff iterators don't automatically`
	`92`	`+ // skip these).`
	`93`	`+ if (node.isChildMaskOn(it.pos())) continue;`
`90`	`94`	`if (check(it)) it.setValueOn(/on=*/true);`
`91`	`95`	`}`
`92`	`96`	`}`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+OpenVDB:`
	`2`	`+ - Bug Fixes::`
	`3`	`+ - Fixed an occurance of undefined behaviour in tools::activate (though this would typically not have manifested with any unintended behaviour)`