From: Francois-Xavier Le Bail <devel.fx.lebail@orange.fr>
Date: Sun, 8 Jul 2018 13:03:45 +0000 (+0200)
Subject: DVMRP: Fix an undefined behavior at runtime
X-Git-Tag: tcpdump-4.9.3~118
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/64759158259054a12011ada20cfff503883ed434

DVMRP: Fix an undefined behavior at runtime

Found with -fsanitize=undefined clang compiler option.

The error was:
print-dvmrp.c:238:27: runtime error: left shift of 240 by 24 places cannot
be represented in type 'int'

(cherry picked from commit bc3e9de3e4cfdf8edc7f486d6918bec8e14903bb)
---

diff --git a/print-dvmrp.c b/print-dvmrp.c
index e6e87667..36a8d5ba 100644
--- a/print-dvmrp.c
+++ b/print-dvmrp.c
@@ -231,7 +231,7 @@ print_probe(netdissect_options *ndo,
 		ND_PRINT((ndo, " [|}"));
 		return (0);
 	}
-	genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
+	genid = EXTRACT_32BITS(bp);
 	bp += 4;
 	len -= 4;
 	ND_PRINT((ndo, ndo->ndo_vflag > 1 ? "\n\t" : " "));