From: Cliff Clark <Cliff_Clark@selinc.com>
Date: Thu, 11 Apr 2024 21:48:13 +0000 (-0700)
Subject: lib: Fix a buffer underflow in _lldpctl_dump_in_atom
X-Git-Tag: 1.0.19~55
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f131aa876233feef1a215d9c975e295e66a11cc6;p=thirdparty%2Flldpd.git

lib: Fix a buffer underflow in _lldpctl_dump_in_atom

Do not write a zero byte before the beginning of the buffer when
_lldpctl_dump_in_atom is called with a zero length atom.
---

diff --git a/src/lib/atom.c b/src/lib/atom.c
index 04011d44..8842ee06 100644
--- a/src/lib/atom.c
+++ b/src/lib/atom.c
@@ -649,7 +649,7 @@ _lldpctl_dump_in_atom(lldpctl_atom_t *atom, const uint8_t *input, size_t size, c
 		snprintf(buffer + i * 3, 4, "%02x%c", *(u_int8_t *)(input + i), sep);
 	if (max > 0 && size > max)
 		snprintf(buffer + i * 3, sizeof(truncation) + 1, "%s", truncation);
-	else
+	else if (i > 0)
 		*(buffer + i * 3 - 1) = 0;
 	return buffer;
 }