From 01e51ed78070703c7e078f1519ad59af38e2888a Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Tue, 30 Jul 2024 22:06:03 +0300 Subject: [PATCH] Replace static buf with a stack-allocated one in 'seg' extension The buffer is used only locally within the function. Also, the initialization to '0' characters was unnecessary, the initial content were always overwritten with sprintf(). I don't understand why it was done that way, but it's been like that since forever. In the passing, change from sprintf() to snprintf(). The buffer was long enough so sprintf() was fine, but this makes it more obvious that there's no risk of a buffer overflow. Reviewed-by: Robert Haas Discussion: https://www.postgresql.org/message-id/7f86e06a-98c5-4ce3-8ec9-3885c8de0358@iki.fi --- contrib/seg/segparse.y | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/contrib/seg/segparse.y b/contrib/seg/segparse.y index 729d4b6390b..9635c3af6e6 100644 --- a/contrib/seg/segparse.y +++ b/contrib/seg/segparse.y @@ -29,14 +29,6 @@ static bool seg_atof(char *value, float *result, struct Node *escontext); static int sig_digits(const char *value); -static char strbuf[25] = { - '0', '0', '0', '0', '0', - '0', '0', '0', '0', '0', - '0', '0', '0', '0', '0', - '0', '0', '0', '0', '0', - '0', '0', '0', '0', '\0' -}; - %} /* BISON Declarations */ @@ -69,11 +61,13 @@ static char strbuf[25] = { range: boundary PLUMIN deviation { + char strbuf[25]; + result->lower = $1.val - $3.val; result->upper = $1.val + $3.val; - sprintf(strbuf, "%g", result->lower); + snprintf(strbuf, sizeof(strbuf), "%g", result->lower); result->l_sigd = Max(sig_digits(strbuf), Max($1.sigd, $3.sigd)); - sprintf(strbuf, "%g", result->upper); + snprintf(strbuf, sizeof(strbuf), "%g", result->upper); result->u_sigd = Max(sig_digits(strbuf), Max($1.sigd, $3.sigd)); result->l_ext = '\0'; result->u_ext = '\0';