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| author | Joe Stringer <joe@wand.net.nz> | 2020-03-29 15:53:40 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-03-30 13:45:05 -0700 |
| commit | 7ae215d23c12a939005f35d1848ca55b6109b9c0 (patch) | |
| tree | bc88bf441433f5bf7a3d66610adb5d1ad1707390 /include/net/sock.h | |
| parent | 71489e21d720a09388b565d60ef87ae993c10528 (diff) | |
| download | linux-7ae215d23c12a939005f35d1848ca55b6109b9c0.tar.gz linux-7ae215d23c12a939005f35d1848ca55b6109b9c0.tar.bz2 linux-7ae215d23c12a939005f35d1848ca55b6109b9c0.zip | |
bpf: Don't refcount LISTEN sockets in sk_assign()
Avoid taking a reference on listen sockets by checking the socket type
in the sk_assign and in the corresponding skb_steal_sock() code in the
the transport layer, and by ensuring that the prefetch free (sock_pfree)
function uses the same logic to check whether the socket is refcounted.
Suggested-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Joe Stringer <joe@wand.net.nz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200329225342.16317-4-joe@wand.net.nz
Diffstat (limited to 'include/net/sock.h')
| -rw-r--r-- | include/net/sock.h | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index f81d528845f6..6d84784d33fa 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2537,6 +2537,21 @@ skb_sk_is_prefetched(struct sk_buff *skb) #endif /* CONFIG_INET */ } +/* This helper checks if a socket is a full socket, + * ie _not_ a timewait or request socket. + */ +static inline bool sk_fullsock(const struct sock *sk) +{ + return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV); +} + +static inline bool +sk_is_refcounted(struct sock *sk) +{ + /* Only full sockets have sk->sk_flags. */ + return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE); +} + /** * skb_steal_sock * @skb to steal the socket from @@ -2549,6 +2564,8 @@ skb_steal_sock(struct sk_buff *skb, bool *refcounted) struct sock *sk = skb->sk; *refcounted = true; + if (skb_sk_is_prefetched(skb)) + *refcounted = sk_is_refcounted(sk); skb->destructor = NULL; skb->sk = NULL; return sk; @@ -2557,14 +2574,6 @@ skb_steal_sock(struct sk_buff *skb, bool *refcounted) return NULL; } -/* This helper checks if a socket is a full socket, - * ie _not_ a timewait or request socket. - */ -static inline bool sk_fullsock(const struct sock *sk) -{ - return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV); -} - /* Checks if this SKB belongs to an HW offloaded socket * and whether any SW fallbacks are required based on dev. * Check decrypted mark in case skb_orphan() cleared socket. |