From: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
Date: Tue, 20 Nov 2018 22:56:07 -0200
> On Mon, Nov 19, 2018 at 12:39:55PM -0800, David Miller wrote:
>> From: Xin Long <lucien.xin@xxxxxxxxx>
>> Date: Sun, 18 Nov 2018 15:07:38 +0800
>>
>> > Now sctp increases sk_wmem_alloc by 1 when doing set_owner_w for the
>> > skb allocked in sctp_packet_transmit and decreases by 1 when freeing
>> > this skb.
>> >
>> > But when this skb goes through networking stack, some subcomponents
>> > might change skb->truesize and add the same amount on sk_wmem_alloc.
>> > However sctp doesn't know the amount to decrease by, it would cause
>> > a leak on sk->sk_wmem_alloc and the sock can never be freed.
>> >
>> > Xiumei found this issue when it hit esp_output_head() by using sctp
>> > over ipsec, where skb->truesize is added and so is sk->sk_wmem_alloc.
>> >
>> > Since sctp has used sk_wmem_queued to count for writable space since
>> > Commit cd305c74b0f8 ("sctp: use sk_wmem_queued to check for writable
>> > space"), it's ok to fix it by counting sk_wmem_alloc by skb truesize
>> > in sctp_packet_transmit.
>> >
>> > Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible")
>> > Reported-by: Xiumei Mu <xmu@xxxxxxxxxx>
>> > Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
>>
>> Applied and queued up for -stable.
>
> Dave, is there a way that we can check to which versions you queued it
> up?
I queued up the patch is, and then do backports as needed.
If you think it's too complex to backport this, I'll toss it from the
-stable queue and that's what I have just done.
