ndctl/namespace: protect against under|over-flow w bad param.align

A coverity scan highlighted an integer underflow when param.align
is 0, and an integer overflow when the parsing of param.align fails
and returns ULLONG_MAX.

Add explicit checks for both values.

Reviewed-by: Dave Jiang <[email protected]>
Link: https://lore.kernel.org/r/5f8a8a6cf332ec9ceb636180b9dd5cbf801f1e6e.1741304303.git.alison.schofield@intel.com
Signed-off-by: Alison Schofield <[email protected]>

Author: AlisonSchofield

ndctl/namespace.c

@@ -2087,7 +2087,11 @@ static int namespace_rw_infoblock(struct ndctl_namespace *ndns,
 			unsigned long long size = parse_size64(param.size);
 			align = parse_size64(param.align);
 
-			if (align < ULLONG_MAX && !IS_ALIGNED(size, align)) {
+			if (align == 0 || align == ULLONG_MAX) {
+				error("invalid alignment:%s\n", param.align);
+				rc = -EINVAL;
+			}
+			if (!IS_ALIGNED(size, align)) {
 				error("--size=%s not aligned to %s\n", param.size,
 					param.align);