From 9016a2a3dc4ee7e41ecda5a8b3a3d3481de94964 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sun, 27 Mar 2022 12:57:46 -0400 Subject: [PATCH] Fix breakage of get_ps_display() in the PS_USE_NONE case. Commit 8c6d30f21 caused this function to fail to set *displen in the PS_USE_NONE code path. If the variable's previous value had been negative, that'd lead to a memory clobber at some call sites. We'd managed not to notice due to very thin test coverage of such configurations, but this appears to explain buildfarm member lorikeet's recent struggles. Credit to Andrew Dunstan for spotting the problem. Back-patch to v13 where the bug was introduced. Discussion: https://postgr.es/m/136102.1648320427@sss.pgh.pa.us --- src/backend/utils/misc/ps_status.c | 1 + 1 file changed, 1 insertion(+) diff --git a/src/backend/utils/misc/ps_status.c b/src/backend/utils/misc/ps_status.c index 1e8596e664..46d73280d5 100644 --- a/src/backend/utils/misc/ps_status.c +++ b/src/backend/utils/misc/ps_status.c @@ -443,6 +443,7 @@ get_ps_display(int *displen) return ps_buffer + ps_buffer_fixed_size; #else + *displen = 0; return ""; #endif }