Re: Undefined behavior detected by new clang's ubsan

John Naylor <johncnaylorls@gmail.com>

From: John Naylor <johncnaylorls@gmail.com>

To: Alexander Lakhin <exclusion@gmail.com>

Cc: pgsql-hackers <pgsql-hackers@postgresql.org>

Date: 2026-01-20T06:13:30Z

Lists: pgsql-hackers

On Tue, Jan 20, 2026 at 12:00 PM Alexander Lakhin <exclusion@gmail.com> wrote:
> ../../src/include/lib/sort_template.h:314:15: runtime error: applying non-zero offset 8 to null pointer
> SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior ../../src/include/lib/sort_template.h:314:15

Where does it think a NULL pointer is coming from?

-- 
John Naylor
Amazon Web Services

Commits

Future-proof sort template against undefined behavior
- 7467041cde9e 19 (unreleased) landed
Fix various instances of undefined behavior
- 176dffdf7d2a 19 (unreleased) landed
- fc56793c9ae5 14.21 landed
- b5e1cd2fdca1 18.2 landed
- 73ac2b37401d 16.12 landed
- 6b81a1c7c905 15.16 landed
- 1662cd0cb7ae 17.8 landed