From: Petr Machata <petrm@nvidia.com>
Date: Mon, 27 Jun 2022 13:18:21 +0000 (+0200)
Subject: ip: Fix size_columns() for very large values
X-Git-Tag: v5.19.0~16
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=024103923a5c826e40c993be4ee2ada5536cb66a;p=thirdparty%2Fiproute2.git

ip: Fix size_columns() for very large values

For values near the 64-bit boundary, the iterative application of
powi *= 10 causes powi to overflow without the termination condition of
powi >= val having ever been satisfied. Instead, when determining the
length of the number, iterate val /= 10 and terminate when it's a single
digit.

Fixes: 49437375b6c1 ("ip: dynamically size columns when printing stats")
CC: Tariq Toukan <tariqt@nvidia.com>
CC: Itay Aveksis <itayav@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---

diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index 17341d287..5a3b1cae4 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -549,7 +549,7 @@ static void print_vfinfo(FILE *fp, struct ifinfomsg *ifi, struct rtattr *vfinfo)
 void size_columns(unsigned int cols[], unsigned int n, ...)
 {
 	unsigned int i, len;
-	uint64_t val, powi;
+	uint64_t val;
 	va_list args;
 
 	va_start(args, n);
@@ -560,7 +560,7 @@ void size_columns(unsigned int cols[], unsigned int n, ...)
 		if (human_readable)
 			continue;
 
-		for (len = 1, powi = 10; powi < val; len++, powi *= 10)
+		for (len = 1; val > 9; len++, val /= 10)
 			/* nothing */;
 		if (len > cols[i])
 			cols[i] = len;