Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2023-09-06

We've added 9 non-merge commits during the last 6 day(s) which contain
a total of 12 files changed, 189 insertions(+), 44 deletions(-).

The main changes are:

1) Fix bpf_sk_storage to address an invalid wait context lockdep
   report and another one to address missing omem uncharge,
   from Martin KaFai Lau.

2) Two BPF recursion detection related fixes,
   from Sebastian Andrzej Siewior.

3) Fix tailcall limit enforcement in trampolines for s390 JIT,
   from Ilya Leoshkevich.

4) Fix a sockmap refcount race where skbs in sk_psock_backlog can
   be referenced after user space side has already skb_consumed them,
   from John Fastabend.

5) Fix BPF CI flake/race wrt sockmap vsock write test where
   the transport endpoint is not connected, from Xu Kuohai.

6) Follow-up doc fix to address a cross-link warning,
   from Eduard Zingerman.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Check bpf_sk_storage has uncharged sk_omem_alloc
  bpf: bpf_sk_storage: Fix the missing uncharge in sk_omem_alloc
  bpf: bpf_sk_storage: Fix invalid wait context lockdep report
  s390/bpf: Pass through tail call counter in trampolines
  bpf: Assign bpf_tramp_run_ctx::saved_run_ctx before recursion check.
  bpf: Invoke __bpf_prog_exit_sleepable_recur() on recursion in kern_sys_bpf().
  bpf, sockmap: Fix skb refcnt race after locking changes
  docs/bpf: Fix "file doesn't exist" warnings in {llvm_reloc,btf}.rst
  selftests/bpf: Fix a CI failure caused by vsock write
====================

Link: https://lore.kernel.org/r/20230906095117.16941-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 8 insertions, 4 deletions

diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index a0659fc29bcc..6c31eefbd777 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -612,12 +612,18 @@ static int sk_psock_skb_ingress_self(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)
 {
+	int err = 0;
+
 	if (!ingress) {
 		if (!sock_writeable(psock->sk))
 			return -EAGAIN;
 		return skb_send_sock(psock->sk, skb, off, len);
 	}
-	return sk_psock_skb_ingress(psock, skb, off, len);
+	skb_get(skb);
+	err = sk_psock_skb_ingress(psock, skb, off, len);
+	if (err < 0)
+		kfree_skb(skb);
+	return err;
 }
 
 static void sk_psock_skb_state(struct sk_psock *psock,
@@ -685,9 +691,7 @@ static void sk_psock_backlog(struct work_struct *work)
 		} while (len);
 
 		skb = skb_dequeue(&psock->ingress_skb);
-		if (!ingress) {
-			kfree_skb(skb);
-		}
+		kfree_skb(skb);
 	}
 end:
 	mutex_unlock(&psock->work_mutex);