ipv6: Fix nexthop refcnt leak when creating ipv6 route info

ip6_route_info_create() invokes nexthop_get(), which increases the
refcount of the "nh".

When ip6_route_info_create() returns, local variable "nh" becomes
invalid, so the refcount should be decreased to keep refcount balanced.

The reference counting issue happens in one exception handling path of
ip6_route_info_create(). When nexthops can not be used with source
routing, the function forgets to decrease the refcnt increased by
nexthop_get(), causing a refcnt leak.

Fix this issue by pulling up the error source routing handling when
nexthops can not be used with source routing.

Fixes: f88d8ea67f ("ipv6: Plumb support for nexthop object in a fib6_info")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xiyu Yang 2020-07-25 16:02:18 +08:00 committed by David S. Miller
parent fa662d7816
commit 706ec91916

View File

@ -3685,14 +3685,14 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
rt->fib6_src.plen = cfg->fc_src_len;
#endif
if (nh) {
if (!nexthop_get(nh)) {
NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
goto out;
}
if (rt->fib6_src.plen) {
NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing");
goto out;
}
if (!nexthop_get(nh)) {
NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
goto out;
}
rt->nh = nh;
fib6_nh = nexthop_fib6_nh(rt->nh);
} else {