Commit cf673ed0 authored Mar 30, 2020 by Florian Westphal Committed by David S. Miller Mar 30, 2020

net: fix fraglist segmentation reference count leak



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: 3a1296a3 ("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>

parent bde1b56f

net/core/skbuff.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -3668,6 +3668,7 @@ struct sk_buff skb_segment_list(struct sk_buff skb,

		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));

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