sharpetronics/PostgreSQL
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-02 00:01:40 -04:00
Code Issues Projects Releases Wiki Activity

Fix off-by-one in LimitAdditionalPins()

Browse Source 
Due to the bug LimitAdditionalPins() could return 0, violating
LimitAdditionalPins()'s API ("One additional pin is always allowed"). This
could be hit when setting shared_buffers very low and using a fair amount of
concurrency.

This bug was introduced in 31966b151e6a.

Author: "Anton A. Melnikov" <aamelnikov@inbox.ru>
Reported-by: "Anton A. Melnikov" <aamelnikov@inbox.ru>
Reported-by: Victoria Shepard
Discussion: https://postgr.es/m/ae46f2fb-5586-3de0-b54b-1bb0f6410ebd@inbox.ru
Backpatch: 16-
This commit is contained in:
Andres Freund 2023-07-24 19:07:52 -07:00
parent d6677b93c7
commit f3bc519288
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/backend/storage/buffer/bufmgr.c
View File

@ -1767,7 +1767,7 @@ LimitAdditionalPins(uint32 *additional_pins)
*/
max_proportional_pins -= PrivateRefCountOverflowed + REFCOUNT_ARRAY_ENTRIES;
if (max_proportional_pins < 0)
if (max_proportional_pins <= 0)
max_proportional_pins = 1;
if (*additional_pins > max_proportional_pins)