Re: [PATCH] ipv6: frags: Fix bogus skb->sk in reassembled packets
From: Eric Dumazet <edumazet@google.com>
Date: 2018-12-20 13:27:05
On Thu, Dec 20, 2018 at 5:20 AM Herbert Xu [off-list ref] wrote:
quoted hunk ↗ jump to hunk
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 <redacted> 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 [off-list ref]
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.