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authorJohn Fastabend <john.fastabend@gmail.com>2020-10-09 11:37:17 -0700
committerAlexei Starovoitov <ast@kernel.org>2020-10-11 18:00:57 -0700
commit9047f19e7ccba5073d983dd3882b5f46086b578a (patch)
tree5164babc74ec0b6b0a44470acaa254ce872c6487 /net/core
parent29545f4977cf7c7b721aa4d43418632af1d6836d (diff)
downloadlinux-9047f19e7ccba5073d983dd3882b5f46086b578a.tar.bz2
bpf, sockmap: Remove dropped data on errors in redirect case
In the sk_skb redirect case we didn't handle the case where we overrun the sk_rmem_alloc entry on ingress redirect or sk_wmem_alloc on egress. Because we didn't have anything implemented we simply dropped the skb. This meant data could be dropped if socket memory accounting was in place. This fixes the above dropped data case by moving the memory checks later in the code where we actually do the send or recv. This pushes those checks into the workqueue and allows us to return an EAGAIN error which in turn allows us to try again later from the workqueue. Fixes: 51199405f9672 ("bpf: skb_verdict, support SK_PASS on RX BPF path") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/160226863689.5692.13861422742592309285.stgit@john-Precision-5820-Tower
Diffstat (limited to 'net/core')
-rw-r--r--net/core/skmsg.c28
1 files changed, 14 insertions, 14 deletions
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index 7389d5d7e7f8..880b84baab5e 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -433,10 +433,12 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb)
static int sk_psock_handle_skb(struct sk_psock *psock, struct sk_buff *skb,
u32 off, u32 len, bool ingress)
{
- if (ingress)
- return sk_psock_skb_ingress(psock, skb);
- else
+ if (!ingress) {
+ if (!sock_writeable(psock->sk))
+ return -EAGAIN;
return skb_send_sock_locked(psock->sk, skb, off, len);
+ }
+ return sk_psock_skb_ingress(psock, skb);
}
static void sk_psock_backlog(struct work_struct *work)
@@ -709,30 +711,28 @@ static void sk_psock_skb_redirect(struct sk_buff *skb)
{
struct sk_psock *psock_other;
struct sock *sk_other;
- bool ingress;
sk_other = tcp_skb_bpf_redirect_fetch(skb);
+ /* This error is a buggy BPF program, it returned a redirect
+ * return code, but then didn't set a redirect interface.
+ */
if (unlikely(!sk_other)) {
kfree_skb(skb);
return;
}
psock_other = sk_psock(sk_other);
+ /* This error indicates the socket is being torn down or had another
+ * error that caused the pipe to break. We can't send a packet on
+ * a socket that is in this state so we drop the skb.
+ */
if (!psock_other || sock_flag(sk_other, SOCK_DEAD) ||
!sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED)) {
kfree_skb(skb);
return;
}
- ingress = tcp_skb_bpf_ingress(skb);
- if ((!ingress && sock_writeable(sk_other)) ||
- (ingress &&
- atomic_read(&sk_other->sk_rmem_alloc) <=
- sk_other->sk_rcvbuf)) {
- skb_queue_tail(&psock_other->ingress_skb, skb);
- schedule_work(&psock_other->work);
- } else {
- kfree_skb(skb);
- }
+ skb_queue_tail(&psock_other->ingress_skb, skb);
+ schedule_work(&psock_other->work);
}
static void sk_psock_tls_verdict_apply(struct sk_buff *skb, int verdict)