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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Implement -fsanitize=bounds-strict"
href="https://bugs.llvm.org/show_bug.cgi?id=45379">45379</a>
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<th>Summary</th>
<td>Implement -fsanitize=bounds-strict
</td>
</tr>
<tr>
<th>Product</th>
<td>compiler-rt
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
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<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>ubsan
</td>
</tr>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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</tr>
<tr>
<th>Reporter</th>
<td>keescook@chromium.org
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=23300" name="attach_23300" title="bounds checking PoC">attachment 23300</a> <a href="attachment.cgi?id=23300&action=edit" title="bounds checking PoC">[details]</a></span>
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?</pre>
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