[llvm-bugs] [Bug 45379] New: Implement -fsanitize=bounds-strict

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=45379

            Bug ID: 45379
           Summary: Implement -fsanitize=bounds-strict
           Product: compiler-rt
           Version: unspecified
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: ubsan
          Assignee: unassignedbugs at nondot.org
          Reporter: keescook at chromium.org
                CC: llvm-bugs at lists.llvm.org

Created attachment 23300
  --> https://bugs.llvm.org/attachment.cgi?id=23300&action=edit
bounds checking PoC

I'd like Clang's UBSan bounds checker to disallow the old-style 0-byte and
1-byte array declarations as being seen as a variant of a flexible array
member.

As it turns out, GCC has "-fsanitize=bounds-strict" which gets me close to what
I'd like (it still allows 0-byte):


(Built with gcc -fsanitize=bounds)
$ ./bounds-gcc abc
flex (should always be okay): ok (no trap!)
zero (should be okay, treated as flex): ok (no trap!)
one (should fail): FAIL (this should have trapped!)
non_flex (should fail): FAIL (this should have trapped!)
non_trailing (absolutely should fail): Illegal instruction (core dumped)

(Built with gcc -fsanitize=bounds-strict)
$ ./bounds-gcc abc
flex (should always be okay): ok (no trap!)
zero (should be okay, treated as flex): ok (no trap!)
one (should fail): Illegal instruction (core dumped)

(Built with clang -fsanitize=bounds)
$ ./bounds-clang abc
flex (should always be okay): ok (no trap!)
zero (should be okay, treated as flex): ok (no trap!)
one (should fail): FAIL (this should have trapped!)
non_flex (should fail): Illegal instruction (core dumped)


Could Clang's UBSan grow the "strict" version of this to check 1-byte arrays?

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20200331/5b354a48/attachment.html>