summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorKuniyuki Iwashima <kuniyu@amazon.com>2023-02-09 16:22:01 -0800
committerJakub Kicinski <kuba@kernel.org>2023-02-10 19:53:42 -0800
commitca43ccf41224b023fc290073d5603a755fd12eed (patch)
tree4bdfff84e25e21c93e55750af146804037d9f00f
parent7fa0b526f865cb42aa33917fd02a92cb03746f4d (diff)
dccp/tcp: Avoid negative sk_forward_alloc by ipv6_pinfo.pktoptions.
Eric Dumazet pointed out [0] that when we call skb_set_owner_r() for ipv6_pinfo.pktoptions, sk_rmem_schedule() has not been called, resulting in a negative sk_forward_alloc. We add a new helper which clones a skb and sets its owner only when sk_rmem_schedule() succeeds. Note that we move skb_set_owner_r() forward in (dccp|tcp)_v6_do_rcv() because tcp_send_synack() can make sk_forward_alloc negative before ipv6_opt_accepted() in the crossed SYN-ACK or self-connect() cases. [0]: https://lore.kernel.org/netdev/CANn89iK9oc20Jdi_41jb9URdF210r7d1Y-+uypbMSbOfY6jqrg@mail.gmail.com/ Fixes: 323fbd0edf3f ("net: dccp: Add handling of IPV6_PKTOPTIONS to dccp_v6_do_rcv()") Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--include/net/sock.h13
-rw-r--r--net/dccp/ipv6.c7
-rw-r--r--net/ipv6/tcp_ipv6.c10
3 files changed, 18 insertions, 12 deletions
diff --git a/include/net/sock.h b/include/net/sock.h
index dcd72e6285b2..556209727633 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2434,6 +2434,19 @@ static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struc
return false;
}
+static inline struct sk_buff *skb_clone_and_charge_r(struct sk_buff *skb, struct sock *sk)
+{
+ skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
+ if (skb) {
+ if (sk_rmem_schedule(sk, skb, skb->truesize)) {
+ skb_set_owner_r(skb, sk);
+ return skb;
+ }
+ __kfree_skb(skb);
+ }
+ return NULL;
+}
+
static inline void skb_prepare_for_gro(struct sk_buff *skb)
{
if (skb->destructor != sock_wfree) {
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 4260fe466993..b9d7c3dd1cb3 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -551,11 +551,9 @@ static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
*own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), NULL);
/* Clone pktoptions received with SYN, if we own the req */
if (*own_req && ireq->pktopts) {
- newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC);
+ newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk);
consume_skb(ireq->pktopts);
ireq->pktopts = NULL;
- if (newnp->pktoptions)
- skb_set_owner_r(newnp->pktoptions, newsk);
}
return newsk;
@@ -615,7 +613,7 @@ static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
--ANK (980728)
*/
if (np->rxopt.all)
- opt_skb = skb_clone(skb, GFP_ATOMIC);
+ opt_skb = skb_clone_and_charge_r(skb, sk);
if (sk->sk_state == DCCP_OPEN) { /* Fast path */
if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
@@ -679,7 +677,6 @@ ipv6_pktoptions:
np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
if (ipv6_opt_accepted(sk, opt_skb,
&DCCP_SKB_CB(opt_skb)->header.h6)) {
- skb_set_owner_r(opt_skb, sk);
memmove(IP6CB(opt_skb),
&DCCP_SKB_CB(opt_skb)->header.h6,
sizeof(struct inet6_skb_parm));
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 0d25e813288d..a52a4f12f146 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1388,14 +1388,11 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
/* Clone pktoptions received with SYN, if we own the req */
if (ireq->pktopts) {
- newnp->pktoptions = skb_clone(ireq->pktopts,
- sk_gfp_mask(sk, GFP_ATOMIC));
+ newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk);
consume_skb(ireq->pktopts);
ireq->pktopts = NULL;
- if (newnp->pktoptions) {
+ if (newnp->pktoptions)
tcp_v6_restore_cb(newnp->pktoptions);
- skb_set_owner_r(newnp->pktoptions, newsk);
- }
}
} else {
if (!req_unhash && found_dup_sk) {
@@ -1467,7 +1464,7 @@ int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
--ANK (980728)
*/
if (np->rxopt.all)
- opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
+ opt_skb = skb_clone_and_charge_r(skb, sk);
reason = SKB_DROP_REASON_NOT_SPECIFIED;
if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
@@ -1553,7 +1550,6 @@ ipv6_pktoptions:
if (np->repflow)
np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
- skb_set_owner_r(opt_skb, sk);
tcp_v6_restore_cb(opt_skb);
opt_skb = xchg(&np->pktoptions, opt_skb);
} else {