From 2121d58091a3d6b53299d774f318cbdfb96076be Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Wed, 23 Mar 2022 13:05:25 -0700 Subject: [PATCH] Don't call fwrite() with len == 0 when writing out relcache init file. Noticed via -fsanitize=undefined. Backpatch to all branches, for the same reasons as 46ab07ffda9. Discussion: https://postgr.es/m/20220323173537.ll7klrglnp4gn2um@alap3.anarazel.de Backpatch: 10- --- src/backend/utils/cache/relcache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c index b790777108..0524cb8541 100644 --- a/src/backend/utils/cache/relcache.c +++ b/src/backend/utils/cache/relcache.c @@ -6168,7 +6168,7 @@ write_item(const void *data, Size len, FILE *fp) { if (fwrite(&len, 1, sizeof(len), fp) != sizeof(len)) elog(FATAL, "could not write init file"); - if (fwrite(data, 1, len, fp) != len) + if (len > 0 && fwrite(data, 1, len, fp) != len) elog(FATAL, "could not write init file"); }