| Message ID | 20171213203337.314-1-dbanerje@akamai.com |
|---|---|
| State | Awaiting Upstream, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | Fix handling of verdicts after NF_QUEUE | expand |
Hi Greg, I'd appreciate if you can take this patch into 4.9-stable. There is no similar patch in tree, so this is not a backport. On Wed, Dec 13, 2017 at 03:33:37PM -0500, Debabrata Banerjee wrote: > A verdict of NF_STOLEN after NF_QUEUE will cause an incorrect return value > and a potential kernel panic via double free of skb's > > This was broken by commit 7034b566a4e7 ("netfilter: fix nf_queue handling") > and subsequently fixed in v4.10 by commit c63cbc460419 ("netfilter: > use switch() to handle verdict cases from nf_hook_slow()"). However that > commit cannot be cleanly cherry-picked to v4.9 > > Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org> Thanks a lot! > --- > > This fix is only needed for v4.9 stable since v4.10+ does not have the > issue > --- > net/netfilter/core.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/net/netfilter/core.c b/net/netfilter/core.c > index 004af030ef1a..d869ea50623e 100644 > --- a/net/netfilter/core.c > +++ b/net/netfilter/core.c > @@ -364,6 +364,11 @@ int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state) > ret = nf_queue(skb, state, &entry, verdict); > if (ret == 1 && entry) > goto next_hook; > + } else { > + /* Implicit handling for NF_STOLEN, as well as any other > + * non conventional verdicts. > + */ > + ret = 0; > } > return ret; > } > -- > 2.15.1 >
On Thu, Dec 14, 2017 at 01:30:08PM +0100, Pablo Neira Ayuso wrote: > Hi Greg, > > I'd appreciate if you can take this patch into 4.9-stable. There is no > similar patch in tree, so this is not a backport. > > On Wed, Dec 13, 2017 at 03:33:37PM -0500, Debabrata Banerjee wrote: > > A verdict of NF_STOLEN after NF_QUEUE will cause an incorrect return value > > and a potential kernel panic via double free of skb's > > > > This was broken by commit 7034b566a4e7 ("netfilter: fix nf_queue handling") > > and subsequently fixed in v4.10 by commit c63cbc460419 ("netfilter: > > use switch() to handle verdict cases from nf_hook_slow()"). However that > > commit cannot be cleanly cherry-picked to v4.9 > > > > Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com> > > Acked-by: Pablo Neira Ayuso <pablo@netfilter.org> > > Thanks a lot! Now applied, thanks. greg k-h
diff --git a/net/netfilter/core.c b/net/netfilter/core.c index 004af030ef1a..d869ea50623e 100644 --- a/net/netfilter/core.c +++ b/net/netfilter/core.c @@ -364,6 +364,11 @@ int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state) ret = nf_queue(skb, state, &entry, verdict); if (ret == 1 && entry) goto next_hook; + } else { + /* Implicit handling for NF_STOLEN, as well as any other + * non conventional verdicts. + */ + ret = 0; } return ret; }
A verdict of NF_STOLEN after NF_QUEUE will cause an incorrect return value and a potential kernel panic via double free of skb's This was broken by commit 7034b566a4e7 ("netfilter: fix nf_queue handling") and subsequently fixed in v4.10 by commit c63cbc460419 ("netfilter: use switch() to handle verdict cases from nf_hook_slow()"). However that commit cannot be cleanly cherry-picked to v4.9 Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com> --- This fix is only needed for v4.9 stable since v4.10+ does not have the issue --- net/netfilter/core.c | 5 +++++ 1 file changed, 5 insertions(+)