tcp: False "Untrusted loop bound" positive, CWE-606

Field doff in struct tcp_hdr is 4 bits wide, so optlen in
tcp_tap_handler() is already bound, but make that explicit.
Reported by Coverity.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Stefano Brivio 2022-04-05 05:54:18 +02:00
parent 975ee8eb2b
commit 6a3f6df865

2
tcp.c
View file

@ -2716,6 +2716,8 @@ int tcp_tap_handler(struct ctx *c, int af, const void *addr,
return 1;
optlen = th->doff * 4UL - sizeof(*th);
/* Static checkers might fail to see this: */
optlen = MIN(optlen, ((1UL << 4) /* from doff width */ - 6) * 4UL);
opts = packet_get(p, 0, sizeof(*th), optlen, NULL);
conn = tcp_hash_lookup(c, af, addr, htons(th->source), htons(th->dest));