Messages in this thread | | | Subject | Re: [PATCH v3] af_netlink: ensure that NLMSG_DONE never fails in dumps | From | Johannes Berg <> | Date | Thu, 09 Nov 2017 03:02:14 +0100 |
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On Thu, 2017-11-09 at 10:42 +0900, Jason A. Donenfeld wrote: > +++ b/net/netlink/af_netlink.c > @@ -2136,7 +2136,7 @@ static int netlink_dump(struct sock *sk) > struct sk_buff *skb = NULL; > struct nlmsghdr *nlh; > struct module *module; > - int len, err = -ENOBUFS; > + int err = -ENOBUFS; > int alloc_min_size; > int alloc_size; > > @@ -2183,9 +2183,10 @@ static int netlink_dump(struct sock *sk) > skb_reserve(skb, skb_tailroom(skb) - alloc_size); > netlink_skb_set_owner_r(skb, sk); > > - len = cb->dump(skb, cb); > + if (nlk->dump_done_errno > 0) > + nlk->dump_done_errno = cb->dump(skb, cb); > > - if (len > 0) { > + if (nlk->dump_done_errno > 0 || skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) { > mutex_unlock(nlk->cb_mutex);
nit: I think your line got a little long here :)
> - memcpy(nlmsg_data(nlh), &len, sizeof(len)); > + memcpy(nlmsg_data(nlh), &nlk->dump_done_errno, sizeof(nlk->dump_done_errno));
and here
> + nlk->dump_done_errno = INT_MAX;
I guess positive values aren't really returned from dump?
johannes
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