[hwasan] Fix a possible null dereference problem

[yingcong-wu]

This is clearly a copy-paste mistake, fix it with this patch.
After checking the local.function_name is not null, it should check the len for local.function_name, not local.name. And this could lead to possible null dereference since the second internal_strlen(local.name) does not guarantee local.name is not null.

[llvmbot]

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Wu Yingcong (yingcong-wu)

Changes

This is clearly a copy-paste mistake, fix it with this patch.

---

Full diff: https://github.com/llvm/llvm-project/pull/77737.diff

1 Files Affected:

• (modified) compiler-rt/lib/hwasan/hwasan_report.cpp (+1-1)

diff --git a/compiler-rt/lib/hwasan/hwasan_report.cpp b/compiler-rt/lib/hwasan/hwasan_report.cpp
index 784cfb904aa275..12a4fa47f21519 100644
--- a/compiler-rt/lib/hwasan/hwasan_report.cpp
+++ b/compiler-rt/lib/hwasan/hwasan_report.cpp
@@ -222,7 +222,7 @@ static void PrintStackAllocations(const StackAllocationsRingBuffer *sa,
         if (!local.has_frame_offset || !local.has_size || !local.has_tag_offset)
           continue;
         if (!(local.name && internal_strlen(local.name)) &&
-            !(local.function_name && internal_strlen(local.name)) &&
+            !(local.function_name && internal_strlen(local.function_name)) &&
             !(local.decl_file && internal_strlen(local.decl_file)))
           continue;
         tag_t obj_tag = base_tag ^ local.tag_offset;

[MaskRay]

Is a test case possible?

[yingcong-wu]

Let me see what I can do to add a test case.

[yingcong-wu]

Sorry, I cannot think of a way to add test for this. Do you have any suggestions?

[yingcong-wu]

Hi, I don't have any ideas on how to build a test case for this, could you please give some direction?
Or can we land this patch without a test?

[yingcong-wu]

Hi @fmayer , could we land this patch without a test?

[vitalybuka]

I don't know if easy, or even possible, to trigger this case in test.

[vitalybuka]

Thanks for the fix!

[yingcong-wu]

No problems.