When forwarding IPv4 packets in udp_tap_handler(), we incorrectly use an IPv6 address test on our IPv4 address (which could cause an out of bounds access), and possibly set our bind interface to the IPv6 interface based on it. Adjust to correctly look at the IPv4 address and IPv4 interface. Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au> --- udp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/udp.c b/udp.c index 561ba604..d55a6827 100644 --- a/udp.c +++ b/udp.c @@ -875,8 +875,8 @@ int udp_tap_handler(struct ctx *c, uint8_t pif, }; const char *bind_if = NULL; - if (!IN6_IS_ADDR_LOOPBACK(&s_in.sin_addr)) - bind_if = c->ip6.ifname_out; + if (!IN4_IS_ADDR_LOOPBACK(&s_in.sin_addr)) + bind_if = c->ip4.ifname_out; if (!IN4_IS_ADDR_UNSPECIFIED(&c->ip4.addr_out) && !IN4_IS_ADDR_LOOPBACK(&s_in.sin_addr)) -- 2.43.2