Messages in this thread | | | Date | Sat, 17 Sep 2022 08:46:42 -0600 | Subject | Re: [PATCH v1] net/ipv4/nexthop: check the return value of nexthop_find_by_id() | From | David Ahern <> |
| |
On 9/17/22 2:29 AM, Nikolay Aleksandrov wrote: > On 17/09/2022 05:30, Li Zhong wrote: >> Check the return value of nexthop_find_by_id(), which could be NULL on >> when not found. So we check to avoid null pointer dereference. >> >> Signed-off-by: Li Zhong <floridsleeves@gmail.com> >> --- >> net/ipv4/nexthop.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c >> index 853a75a8fbaf..9f91bb78eed5 100644 >> --- a/net/ipv4/nexthop.c >> +++ b/net/ipv4/nexthop.c >> @@ -2445,6 +2445,10 @@ static struct nexthop *nexthop_create_group(struct net *net, >> struct nh_info *nhi; >> >> nhe = nexthop_find_by_id(net, entry[i].id); >> + if (!nhe) { >> + err = -EINVAL; >> + goto out_no_nh; >> + } >> if (!nexthop_get(nhe)) { >> err = -ENOENT; >> goto out_no_nh; > > These are validated in nh_check_attr_group() and should exist at this point. > Since remove_nexthop() should run under rtnl I don't see a way for a nexthop > to disappear after nh_check_attr_group() and before nexthop_create_group(). >
exactly. That lookup can't fail because the ids have been validated and all of this is under rtnl preventing nexthop removes.
| |