[lldb] Fix off by one in array index check in Objective C runtime plugin (#118995)

DavidSpickett · web-flow · commit a46ee733d244 · 2024-12-06T16:40:57.000Z
Reported in #116944 / https://pvs-studio.com/en/blog/posts/cpp/1188/.
diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
@@ -3278,7 +3278,7 @@ bool AppleObjCRuntimeV2::NonPointerISACache::EvaluateNonPointerISA(
       }
 
       // If the index is still out of range then this isn't a pointer.
-      if (index > m_indexed_isa_cache.size())
+      if (index >= m_indexed_isa_cache.size())
         return false;
 
       LLDB_LOGF(log, "AOCRT::NPI Evaluate(ret_isa = 0x%" PRIx64 ")",

Original file line number	Diff line number	Diff line change
`@@ -3278,7 +3278,7 @@ bool AppleObjCRuntimeV2::NonPointerISACache::EvaluateNonPointerISA(`
`3278`	`3278`	`}`
`3279`	`3279`
`3280`	`3280`	`// If the index is still out of range then this isn't a pointer.`
`3281`		`- if (index > m_indexed_isa_cache.size())`
	`3281`	`+ if (index >= m_indexed_isa_cache.size())`
`3282`	`3282`	`return false;`
`3283`	`3283`
`3284`	`3284`	`LLDB_LOGF(log, "AOCRT::NPI Evaluate(ret_isa = 0x%" PRIx64 ")",`