From: Florian Westphal <fw@strlen.de>
Date: Mon, 30 Mar 2020 18:51:29 +0200
Subject: net: fix fraglist segmentation reference count leak
Patch-mainline: v5.7-rc1
Git-commit: cf673ed0e057a2dd68d930c6d7e30d53c70c5789
References: bsc#1176447
Xin Long says:
On udp rx path udp_rcv_segment() may do segment where the frag skbs
will get the header copied from the head skb in skb_segment_list()
by calling __copy_skb_header(), which could overwrite the frag skbs'
extensions by __skb_ext_copy() and cause a leak.
This issue was found after loading esp_offload where a sec path ext
is set in the skb.
Fix this by discarding head state of the fraglist skb before replacing
its contents.
Fixes: 3a1296a38d0cf62 ("net: Support GRO/GSO fraglist chaining.")
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Reported-by: Xiumei Mu <xmu@redhat.com>
Tested-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/core/skbuff.c | 1 +
1 file changed, 1 insertion(+)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3669,6 +3669,7 @@ struct sk_buff *skb_segment_list(struct
skb_push(nskb, -skb_network_offset(nskb) + offset);
+ skb_release_head_state(nskb);
__copy_skb_header(nskb, skb);
skb_headers_offset_update(nskb, skb_headroom(nskb) - skb_headroom(skb));