diff mbox series

[iproute2,v2] ip: Fix size_columns() for very large values

Message ID 8f45dcffeb5080d0f4512502cef35ef13ca29871.1656335782.git.petrm@nvidia.com (mailing list archive)
State Accepted
Delegated to: Stephen Hemminger
Headers show
Series [iproute2,v2] ip: Fix size_columns() for very large values | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Petr Machata June 27, 2022, 1:18 p.m. UTC 
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>
---

Notes:
    v2:
    - No changes, but CC the maintainers.

 ip/ipaddress.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index 17341d28..5a3b1cae 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;