git: f021e3573519 - main - bsnmpwalk: Fix crash on invalid data

From: Ed Maste <emaste_at_FreeBSD.org>
Date: Fri, 10 Jan 2025 20:47:55 UTC 
The branch main has been updated by emaste:

URL: https://cgit.FreeBSD.org/src/commit/?id=f021e3573519ff192fc708cda9ca4bba264c96f7

commit f021e3573519ff192fc708cda9ca4bba264c96f7
Author:     Shteryana Shopova <syrinx@FreeBSD.org>
AuthorDate: 2025-01-10 20:30:21 +0000
Commit:     Ed Maste <emaste@FreeBSD.org>
CommitDate: 2025-01-10 20:47:06 +0000

    bsnmpwalk: Fix crash on invalid data
    
    PR:             258570
    Reported by:    Robert Morris <rtm@lcs.mit.edu>
    Reviewed by:    emaste, markj
    Differential Revision: https://reviews.freebsd.org/D48422
---
 usr.sbin/bsnmpd/tools/bsnmptools/bsnmpget.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/usr.sbin/bsnmpd/tools/bsnmptools/bsnmpget.c b/usr.sbin/bsnmpd/tools/bsnmptools/bsnmpget.c
index 81108387d3a4..9d5a693c7c68 100644
--- a/usr.sbin/bsnmpd/tools/bsnmptools/bsnmpget.c
+++ b/usr.sbin/bsnmpd/tools/bsnmptools/bsnmpget.c
@@ -502,7 +502,7 @@ snmptool_walk(struct snmp_toolinfo *snmptoolctx)
 
 			outputs += rc;
 
-			if ((u_int)rc < resp.nbindings) {
+			if ((u_int)rc < resp.nbindings || resp.nbindings == 0) {
 				snmp_pdu_free(&resp);
 				break;
 			}