Invalid memory access in pg_stat_get_subscription

Kuntal Ghosh <kuntalghosh.2007@gmail.com>

From: Kuntal Ghosh <kuntalghosh.2007@gmail.com>

To: PostgreSQL-development <pgsql-hackers@postgresql.org>

Date: 2022-06-07T17:06:23Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Fix off-by-one loop termination condition in pg_stat_get_subscription().
- fb646cbd5a9e 10.22 landed
- d628ce048d47 11.17 landed
- bf4717b09107 15.0 landed
- a36196972b77 13.8 landed
- 5c3b5f7db6ce 14.4 landed
- 435251b859ab 12.12 landed

Attachments

0001-Fix-terminating-condition-while-fetching-the-replica.patch (application/octet-stream) patch 0001

Hello hackers,

While exploring some code in logical replication worker
implementation, I noticed that we're accessing an invalid memory while
traversing LogicalRepCtx->workers[i].
For the above structure, we're allocating
max_logical_replication_workers times LogicalRepWorker amount of
memory in ApplyLauncherShmemSize. But, in the for loop, we're
accessing the max_logical_replication_workers + 1 location which is
resulting in random crashes.

Please find the patch that fixes the issue. I'm not sure whether we
should add a regression test for the same.

-- 
Thanks & Regards,
Kuntal Ghosh