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| author | Xin Long <lucien.xin@gmail.com> | 2018-11-18 08:07:38 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-11-19 21:39:05 +0100 |
| commit | 02968ccf0125d39b08ecef5946300a8a873c0942 (patch) | |
| tree | ce9c31025aa5c8c06708ac3c527a1a8ea4ff4d0a /net | |
| parent | MAINTAINERS: Add myself as third phylib maintainer (diff) | |
| download | linux-02968ccf0125d39b08ecef5946300a8a873c0942.tar.xz linux-02968ccf0125d39b08ecef5946300a8a873c0942.zip | |
sctp: count sk_wmem_alloc by skb truesize in sctp_packet_transmit
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@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sctp/output.c | 21 |
1 files changed, 1 insertions, 20 deletions
diff --git a/net/sctp/output.c b/net/sctp/output.c index 67939ad99c01..88dfa6ae1fb4 100644 --- a/net/sctp/output.c +++ b/net/sctp/output.c @@ -396,25 +396,6 @@ finish: return retval; } -static void sctp_packet_release_owner(struct sk_buff *skb) -{ - sk_free(skb->sk); -} - -static void sctp_packet_set_owner_w(struct sk_buff *skb, struct sock *sk) -{ - skb_orphan(skb); - skb->sk = sk; - skb->destructor = sctp_packet_release_owner; - - /* - * The data chunks have already been accounted for in sctp_sendmsg(), - * therefore only reserve a single byte to keep socket around until - * the packet has been transmitted. - */ - refcount_inc(&sk->sk_wmem_alloc); -} - static void sctp_packet_gso_append(struct sk_buff *head, struct sk_buff *skb) { if (SCTP_OUTPUT_CB(head)->last == head) @@ -601,7 +582,7 @@ int sctp_packet_transmit(struct sctp_packet *packet, gfp_t gfp) if (!head) goto out; skb_reserve(head, packet->overhead + MAX_HEADER); - sctp_packet_set_owner_w(head, sk); + skb_set_owner_w(head, sk); /* set sctp header */ sh = skb_push(head, sizeof(struct sctphdr)); |