| Message ID | 4A9E67A9.7090205@gmail.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
Wed, Sep 02, 2009 at 02:40:09PM CEST, eric.dumazet@gmail.com wrote: >Three bytes of uninitialized kernel memory are currently leaked to user > >Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Reviewed-by: Jiri Pirko <jpirko@redhat.com> >--- >diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c >index 24d17ce..fdb694e 100644 >--- a/net/sched/sch_api.c >+++ b/net/sched/sch_api.c >@@ -1456,6 +1456,8 @@ static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, > nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags); > tcm = NLMSG_DATA(nlh); > tcm->tcm_family = AF_UNSPEC; >+ tcm->tcm__pad1 = 0; >+ tcm->tcm__pad2 = 0; > tcm->tcm_ifindex = qdisc_dev(q)->ifindex; > tcm->tcm_parent = q->handle; > tcm->tcm_handle = q->handle; >-- >To unsubscribe from this list: send the line "unsubscribe netdev" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 02 Sep 2009 14:40:09 +0200 Eric Dumazet <eric.dumazet@gmail.com> wrote: > Three bytes of uninitialized kernel memory are currently leaked to user > > Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> > --- > diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c > index 24d17ce..fdb694e 100644 > --- a/net/sched/sch_api.c > +++ b/net/sched/sch_api.c > @@ -1456,6 +1456,8 @@ static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, > nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags); > tcm = NLMSG_DATA(nlh); > tcm->tcm_family = AF_UNSPEC; > + tcm->tcm__pad1 = 0; > + tcm->tcm__pad2 = 0; > tcm->tcm_ifindex = qdisc_dev(q)->ifindex; > tcm->tcm_parent = q->handle; > tcm->tcm_handle = q->handle; Perhaps __nlmsg_put should just always call memset() for the whole added chunk. It is not like it is critical path in any way, and avoid any of this possible class of errors. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Stephen Hemminger <shemminger@vyatta.com> Date: Wed, 2 Sep 2009 12:05:40 -0700 > On Wed, 02 Sep 2009 14:40:09 +0200 > Eric Dumazet <eric.dumazet@gmail.com> wrote: > >> Three bytes of uninitialized kernel memory are currently leaked to user >> >> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> >> --- >> diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c >> index 24d17ce..fdb694e 100644 >> --- a/net/sched/sch_api.c >> +++ b/net/sched/sch_api.c >> @@ -1456,6 +1456,8 @@ static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, >> nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags); >> tcm = NLMSG_DATA(nlh); >> tcm->tcm_family = AF_UNSPEC; >> + tcm->tcm__pad1 = 0; >> + tcm->tcm__pad2 = 0; >> tcm->tcm_ifindex = qdisc_dev(q)->ifindex; >> tcm->tcm_parent = q->handle; >> tcm->tcm_handle = q->handle; > > Perhaps __nlmsg_put should just always call memset() for the whole > added chunk. It is not like it is critical path in any way, and > avoid any of this possible class of errors. Doing it in __nlmsg_put would effect a lot of code paths. I don't think you can say with certainty that it won't matter, tree wide. What about things like the netfilter conntrack event monitor? Doesn't that emit hundreds of thousands of events per second on a busy firewall? -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Jiri Pirko <jpirko@redhat.com> Date: Wed, 2 Sep 2009 20:09:36 +0200 > Wed, Sep 02, 2009 at 02:40:09PM CEST, eric.dumazet@gmail.com wrote: >>Three bytes of uninitialized kernel memory are currently leaked to user >> >>Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> > > Reviewed-by: Jiri Pirko <jpirko@redhat.com> I'll apply this to net-2.6, thanks everyone. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 02 Sep 2009 22:51:08 -0700 (PDT) David Miller <davem@davemloft.net> wrote: > From: Stephen Hemminger <shemminger@vyatta.com> > Date: Wed, 2 Sep 2009 12:05:40 -0700 > > > On Wed, 02 Sep 2009 14:40:09 +0200 > > Eric Dumazet <eric.dumazet@gmail.com> wrote: > > > >> Three bytes of uninitialized kernel memory are currently leaked to user > >> > >> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> > >> --- > >> diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c > >> index 24d17ce..fdb694e 100644 > >> --- a/net/sched/sch_api.c > >> +++ b/net/sched/sch_api.c > >> @@ -1456,6 +1456,8 @@ static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, > >> nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags); > >> tcm = NLMSG_DATA(nlh); > >> tcm->tcm_family = AF_UNSPEC; > >> + tcm->tcm__pad1 = 0; > >> + tcm->tcm__pad2 = 0; > >> tcm->tcm_ifindex = qdisc_dev(q)->ifindex; > >> tcm->tcm_parent = q->handle; > >> tcm->tcm_handle = q->handle; > > > > Perhaps __nlmsg_put should just always call memset() for the whole > > added chunk. It is not like it is critical path in any way, and > > avoid any of this possible class of errors. > > Doing it in __nlmsg_put would effect a lot of code paths. I don't > think you can say with certainty that it won't matter, tree wide. > > What about things like the netfilter conntrack event monitor? Doesn't > that emit hundreds of thousands of events per second on a busy > firewall? I doubt it would make a noticeable performance difference because the first memset would incur the cache penalty of the write (if any) and later update of fields would be cached.
From: Stephen Hemminger <shemminger@vyatta.com> Date: Wed, 2 Sep 2009 23:34:10 -0700 > I doubt it would make a noticeable performance difference because > the first memset would incur the cache penalty of the write (if any) > and later update of fields would be cached. Indeed, but it also means your store buffer usage is half as effective. And when writing a ton of messages that might be important. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 24d17ce..fdb694e 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -1456,6 +1456,8 @@ static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags); tcm = NLMSG_DATA(nlh); tcm->tcm_family = AF_UNSPEC; + tcm->tcm__pad1 = 0; + tcm->tcm__pad2 = 0; tcm->tcm_ifindex = qdisc_dev(q)->ifindex; tcm->tcm_parent = q->handle; tcm->tcm_handle = q->handle;
Three bytes of uninitialized kernel memory are currently leaked to user Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> --- -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html