From 555802f1e5a475626ea260563b36fe2dc87f6ce4 Mon Sep 17 00:00:00 2001
From: Rob Davies <rmd+git@sanger.ac.uk>
Date: Tue, 30 Jul 2024 12:49:35 +0100
Subject: [PATCH] Stricter limit on POS in vcf_parse()

Limiting POS to 62 bits helps avoid the risk of signed overflow
when it's set to a very extreme value.  The maximum is still
much higher than the length of the longest currently known
reference.
---
 vcf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/vcf.c b/vcf.c
index daedad34d..7ce306f92 100644
--- a/vcf.c
+++ b/vcf.c
@@ -3703,7 +3703,7 @@ int vcf_parse(kstring_t *s, const bcf_hdr_t *h, bcf1_t *v)
 
     overflow = 0;
     char *tmp = p;
-    v->pos = hts_str2uint(p, &p, 63, &overflow);
+    v->pos = hts_str2uint(p, &p, 62, &overflow);
     if (overflow) {
         hts_log_error("Position value '%s' is too large", tmp);
         goto err;