| Message ID | 20181220132010.ltpc4yga5st7zwyu@gondor.apana.org.au |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | ipv6: frags: Fix bogus skb->sk in reassembled packets | expand |
On Thu, Dec 20, 2018 at 5:20 AM Herbert Xu <herbert@gondor.apana.org.au> wrote: > > It was reported that IPsec would crash when it encounters an IPv6 > reassembled packet because skb->sk is non-zero and not a valid > pointer. > > This is because skb->sk is now a union with ip_defrag_offset. > > This patch fixes this by resetting skb->sk when exiting from > the reassembly code. > > Reported-by: Xiumei Mu <xmu@redhat.com> > Fixes: 219badfaade9 ("ipv6: frags: get rid of ip6frag_skb_cb/...") > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> > > diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c > index 5c3c92713096..a98f95fb6eac 100644 > --- a/net/ipv6/reassembly.c > +++ b/net/ipv6/reassembly.c > @@ -378,6 +378,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, > if (skb_try_coalesce(head, fp, &headstolen, &delta)) { > kfree_skb_partial(fp, headstolen); > } else { > + fp->sk = NULL; > if (!skb_shinfo(head)->frag_list) > skb_shinfo(head)->frag_list = fp; > head->data_len += fp->len; I wonder why this have not been done earlier in commit commit 5d407b071dc369c26a38398326ee2be53651cfe4 Author: Taehee Yoo <ap420073@gmail.com> Date: Mon Sep 10 02:47:05 2018 +0900 ip: frags: fix crash in ip_do_fragment() Maybe because the Fixes tag mentioned fa0f527358bd ("ip: use rb trees for IP frag queue.") and IPv6 reasm was not using rbtree ... Oh well.
From: Herbert Xu <herbert@gondor.apana.org.au> Date: Thu, 20 Dec 2018 21:20:10 +0800 > It was reported that IPsec would crash when it encounters an IPv6 > reassembled packet because skb->sk is non-zero and not a valid > pointer. > > This is because skb->sk is now a union with ip_defrag_offset. > > This patch fixes this by resetting skb->sk when exiting from > the reassembly code. > > Reported-by: Xiumei Mu <xmu@redhat.com> > Fixes: 219badfaade9 ("ipv6: frags: get rid of ip6frag_skb_cb/...") > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Applied and queued up for -stable, thanks Herbert.
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index 5c3c92713096..a98f95fb6eac 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -378,6 +378,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, if (skb_try_coalesce(head, fp, &headstolen, &delta)) { kfree_skb_partial(fp, headstolen); } else { + fp->sk = NULL; if (!skb_shinfo(head)->frag_list) skb_shinfo(head)->frag_list = fp; head->data_len += fp->len;
It was reported that IPsec would crash when it encounters an IPv6 reassembled packet because skb->sk is non-zero and not a valid pointer. This is because skb->sk is now a union with ip_defrag_offset. This patch fixes this by resetting skb->sk when exiting from the reassembly code. Reported-by: Xiumei Mu <xmu@redhat.com> Fixes: 219badfaade9 ("ipv6: frags: get rid of ip6frag_skb_cb/...") Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>