On Wed, Jul 24, 2019 at 05:35:09PM +0800, Jia-Ju Bai wrote: > In pfkey_send_policy_notify(), there is an if statement on line 3081 to > check whether xp is NULL: > if (xp && xp->type != XFRM_POLICY_TYPE_MAIN) > > When xp is NULL, it is used by key_notify_policy() on line 3090: > key_notify_policy(xp, ...) > pfkey_xfrm_policy2msg_prep(xp) -- line 2211 > pfkey_xfrm_policy2msg_size(xp) -- line 2046 > for (i=0; i<xp->xfrm_nr; i++) -- line 2026 > t = xp->xfrm_vec + i; -- line 2027 > key_notify_policy(xp, ...) > xp_net(xp) -- line 2231 > return read_pnet(&xp->xp_net); -- line 534
Please don't quote random code lines, explain the problem instead. > > Thus, possible null-pointer dereferences may occur. > > To fix these bugs, xp is checked before calling key_notify_policy(). > > These bugs are found by a static analysis tool STCheck written by us. > > Signed-off-by: Jia-Ju Bai <baijiaju1...@gmail.com> > --- > net/key/af_key.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/net/key/af_key.c b/net/key/af_key.c > index b67ed3a8486c..ced54144d5fd 100644 > --- a/net/key/af_key.c > +++ b/net/key/af_key.c > @@ -3087,6 +3087,8 @@ static int pfkey_send_policy_notify(struct xfrm_policy > *xp, int dir, const struc > case XFRM_MSG_DELPOLICY: > case XFRM_MSG_NEWPOLICY: > case XFRM_MSG_UPDPOLICY: > + if (!xp) > + break; I think this can not happen. Who sends one of these notifications without a pointer to the policy?
