bug#56108: 29.0.50; ASAN use-after-free in re_match_2_internal

[Gerd Möllmann]

On 20. Jun 2022, 21:10 +0200, Eli Zaretskii <eliz@gnu.org>, wrote:

I don't understand why some callers of compile_pattern mark the cache
entry as busy, but some others don't. If a cache entry that is in use
is not marked as busy, then any GC can decide to shrink the cache by
freeing that entry.

struct re_pattern_buffer *bufp;
...
bufp = &compile_pattern (regexp,
...

The address operator is there to confuse the Russians.