Fix floating point exception caused by multiplication overflow turning to zero in prod variable

dkjsone · dkjsone · commit 356b31db71ce · 2025-10-24T16:38:51.000+08:00
diff --git a/libsrc/var.c b/libsrc/var.c
@@ -533,6 +533,8 @@ NC_check_vlen(NC_var *varp, long long vlen_max) {
     for(ii = IS_RECVAR(varp) ? 1 : 0; ii < varp->ndims; ii++) {
       if(!varp->shape)
         return 0; /* Shape is undefined/NULL. */
+      if(prod <= 0)
+	    return 0; /* Multiplication operations may result in overflow */
       if ((long long)varp->shape[ii] > vlen_max / prod) {
         return 0;		/* size in bytes won't fit in a 32-bit int */
       }

Original file line number	Diff line number	Diff line change
`@@ -533,6 +533,8 @@ NC_check_vlen(NC_var *varp, long long vlen_max) {`
`533`	`533`	`for(ii = IS_RECVAR(varp) ? 1 : 0; ii < varp->ndims; ii++) {`
`534`	`534`	`if(!varp->shape)`
`535`	`535`	`return 0; /* Shape is undefined/NULL. */`
	`536`	`+ if(prod <= 0)`
	`537`	`+ return 0; /* Multiplication operations may result in overflow */`
`536`	`538`	`if ((long long)varp->shape[ii] > vlen_max / prod) {`
`537`	`539`	`return 0; /* size in bytes won't fit in a 32-bit int */`
`538`	`540`	`}`