@@ -911,7 +911,7 @@ static int csk_wait_memory(struct chtls_dev *cdev,
struct sock *sk, long *timeo_p)
{
DEFINE_WAIT_FUNC(wait, woken_wake_function);
- int err = 0;
+ int ret, err = 0;
long current_timeo;
long vm_wait = 0;
bool noblock;
@@ -942,10 +942,13 @@ static int csk_wait_memory(struct chtls_dev *cdev,
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
sk->sk_write_pending++;
- sk_wait_event(sk, ¤t_timeo, sk->sk_err ||
- (sk->sk_shutdown & SEND_SHUTDOWN) ||
- (csk_mem_free(cdev, sk) && !vm_wait), &wait);
+ ret = sk_wait_event(sk, ¤t_timeo, sk->sk_err ||
+ (sk->sk_shutdown & SEND_SHUTDOWN) ||
+ (csk_mem_free(cdev, sk) && !vm_wait),
+ &wait);
sk->sk_write_pending--;
+ if (ret < 0)
+ goto do_error;
if (vm_wait) {
vm_wait -= current_timeo;
@@ -1348,6 +1351,7 @@ static int chtls_pt_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
int copied = 0;
int target;
long timeo;
+ int ret;
buffers_freed = 0;
@@ -1423,7 +1427,11 @@ static int chtls_pt_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
if (copied >= target)
break;
chtls_cleanup_rbuf(sk, copied);
- sk_wait_data(sk, &timeo, NULL);
+ ret = sk_wait_data(sk, &timeo, NULL);
+ if (ret < 0) {
+ copied = copied ? : ret;
+ goto unlock;
+ }
continue;
found_ok_skb:
if (!skb->len) {
@@ -1518,6 +1526,8 @@ static int chtls_pt_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
if (buffers_freed)
chtls_cleanup_rbuf(sk, copied);
+
+unlock:
release_sock(sk);
return copied;
}
@@ -1534,6 +1544,7 @@ static int peekmsg(struct sock *sk, struct msghdr *msg,
int copied = 0;
size_t avail; /* amount of available data in current skb */
long timeo;
+ int ret;
lock_sock(sk);
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
@@ -1585,7 +1596,12 @@ static int peekmsg(struct sock *sk, struct msghdr *msg,
release_sock(sk);
lock_sock(sk);
} else {
- sk_wait_data(sk, &timeo, NULL);
+ ret = sk_wait_data(sk, &timeo, NULL);
+ if (ret < 0) {
+ /* here 'copied' is 0 due to previous checks */
+ copied = ret;
+ break;
+ }
}
if (unlikely(peek_seq != tp->copied_seq)) {
@@ -1656,6 +1672,7 @@ int chtls_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
int copied = 0;
long timeo;
int target; /* Read at least this many bytes */
+ int ret;
buffers_freed = 0;
@@ -1747,7 +1764,11 @@ int chtls_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
if (copied >= target)
break;
chtls_cleanup_rbuf(sk, copied);
- sk_wait_data(sk, &timeo, NULL);
+ ret = sk_wait_data(sk, &timeo, NULL);
+ if (ret < 0) {
+ copied = copied ? : ret;
+ goto unlock;
+ }
continue;
found_ok_skb:
@@ -1816,6 +1837,7 @@ int chtls_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
if (buffers_freed)
chtls_cleanup_rbuf(sk, copied);
+unlock:
release_sock(sk);
return copied;
}
@@ -336,7 +336,7 @@ struct sk_filter;
* @sk_cgrp_data: cgroup data for this cgroup
* @sk_memcg: this socket's memory cgroup association
* @sk_write_pending: a write to stream socket waits to start
- * @sk_wait_pending: number of threads blocked on this socket
+ * @sk_disconnects: number of disconnect operations performed on this sock
* @sk_state_change: callback to indicate change in the state of the sock
* @sk_data_ready: callback to indicate there is data to be processed
* @sk_write_space: callback to indicate there is bf sending space available
@@ -429,7 +429,7 @@ struct sock {
unsigned int sk_napi_id;
#endif
int sk_rcvbuf;
- int sk_wait_pending;
+ int sk_disconnects;
struct sk_filter __rcu *sk_filter;
union {
@@ -1189,8 +1189,7 @@ static inline void sock_rps_reset_rxhash(struct sock *sk)
}
#define sk_wait_event(__sk, __timeo, __condition, __wait) \
- ({ int __rc; \
- __sk->sk_wait_pending++; \
+ ({ int __rc, __dis = __sk->sk_disconnects; \
release_sock(__sk); \
__rc = __condition; \
if (!__rc) { \
@@ -1200,8 +1199,7 @@ static inline void sock_rps_reset_rxhash(struct sock *sk)
} \
sched_annotate_sleep(); \
lock_sock(__sk); \
- __sk->sk_wait_pending--; \
- __rc = __condition; \
+ __rc = __dis == __sk->sk_disconnects ? __condition : -EPIPE; \
__rc; \
})
@@ -117,7 +117,7 @@ EXPORT_SYMBOL(sk_stream_wait_close);
*/
int sk_stream_wait_memory(struct sock *sk, long *timeo_p)
{
- int err = 0;
+ int ret, err = 0;
long vm_wait = 0;
long current_timeo = *timeo_p;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
@@ -142,11 +142,13 @@ int sk_stream_wait_memory(struct sock *sk, long *timeo_p)
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
sk->sk_write_pending++;
- sk_wait_event(sk, ¤t_timeo, READ_ONCE(sk->sk_err) ||
- (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN) ||
- (sk_stream_memory_free(sk) &&
- !vm_wait), &wait);
+ ret = sk_wait_event(sk, ¤t_timeo, READ_ONCE(sk->sk_err) ||
+ (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN) ||
+ (sk_stream_memory_free(sk) && !vm_wait),
+ &wait);
sk->sk_write_pending--;
+ if (ret < 0)
+ goto do_error;
if (vm_wait) {
vm_wait -= current_timeo;
@@ -597,7 +597,6 @@ static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
add_wait_queue(sk_sleep(sk), &wait);
sk->sk_write_pending += writebias;
- sk->sk_wait_pending++;
/* Basic assumption: if someone sets sk->sk_err, he _must_
* change state of the socket from TCP_SYN_*.
@@ -613,7 +612,6 @@ static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
}
remove_wait_queue(sk_sleep(sk), &wait);
sk->sk_write_pending -= writebias;
- sk->sk_wait_pending--;
return timeo;
}
@@ -642,6 +640,7 @@ int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
return -EINVAL;
if (uaddr->sa_family == AF_UNSPEC) {
+ sk->sk_disconnects++;
err = sk->sk_prot->disconnect(sk, flags);
sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
goto out;
@@ -696,6 +695,7 @@ int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
tcp_sk(sk)->fastopen_req &&
tcp_sk(sk)->fastopen_req->data ? 1 : 0;
+ int dis = sk->sk_disconnects;
/* Error code is set above */
if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
@@ -704,6 +704,11 @@ int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
err = sock_intr_errno(timeo);
if (signal_pending(current))
goto out;
+
+ if (dis != sk->sk_disconnects) {
+ err = -EPIPE;
+ goto out;
+ }
}
/* Connection was closed by RST, timeout, ICMP error
@@ -725,6 +730,7 @@ int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
sock_error:
err = sock_error(sk) ? : -ECONNABORTED;
sock->state = SS_UNCONNECTED;
+ sk->sk_disconnects++;
if (sk->sk_prot->disconnect(sk, flags))
sock->state = SS_DISCONNECTING;
goto out;
@@ -1145,7 +1145,6 @@ struct sock *inet_csk_clone_lock(const struct sock *sk,
if (newsk) {
struct inet_connection_sock *newicsk = inet_csk(newsk);
- newsk->sk_wait_pending = 0;
inet_sk_set_state(newsk, TCP_SYN_RECV);
newicsk->icsk_bind_hash = NULL;
newicsk->icsk_bind2_hash = NULL;
@@ -831,7 +831,9 @@ ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
*/
if (!skb_queue_empty(&sk->sk_receive_queue))
break;
- sk_wait_data(sk, &timeo, NULL);
+ ret = sk_wait_data(sk, &timeo, NULL);
+ if (ret < 0)
+ break;
if (signal_pending(current)) {
ret = sock_intr_errno(timeo);
break;
@@ -2442,7 +2444,11 @@ static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
__sk_flush_backlog(sk);
} else {
tcp_cleanup_rbuf(sk, copied);
- sk_wait_data(sk, &timeo, last);
+ err = sk_wait_data(sk, &timeo, last);
+ if (err < 0) {
+ err = copied ? : err;
+ goto out;
+ }
}
if ((flags & MSG_PEEK) &&
@@ -2966,12 +2972,6 @@ int tcp_disconnect(struct sock *sk, int flags)
int old_state = sk->sk_state;
u32 seq;
- /* Deny disconnect if other threads are blocked in sk_wait_event()
- * or inet_wait_for_connect().
- */
- if (sk->sk_wait_pending)
- return -EBUSY;
-
if (old_state != TCP_CLOSE)
tcp_set_state(sk, TCP_CLOSE);
@@ -307,6 +307,8 @@ static int tcp_bpf_recvmsg_parser(struct sock *sk,
}
data = tcp_msg_wait_data(sk, psock, timeo);
+ if (data < 0)
+ return data;
if (data && !sk_psock_queue_empty(psock))
goto msg_bytes_ready;
copied = -EAGAIN;
@@ -351,6 +353,8 @@ static int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
data = tcp_msg_wait_data(sk, psock, timeo);
+ if (data < 0)
+ return data;
if (data) {
if (!sk_psock_queue_empty(psock))
goto msg_bytes_ready;
@@ -3098,12 +3098,6 @@ static int mptcp_disconnect(struct sock *sk, int flags)
{
struct mptcp_sock *msk = mptcp_sk(sk);
- /* Deny disconnect if other threads are blocked in sk_wait_event()
- * or inet_wait_for_connect().
- */
- if (sk->sk_wait_pending)
- return -EBUSY;
-
/* We are on the fastopen error path. We can't call straight into the
* subflows cleanup code due to lock nesting (we are already under
* msk->firstsocket lock).
@@ -3173,7 +3167,6 @@ struct sock *mptcp_sk_clone_init(const struct sock *sk,
inet_sk(nsk)->pinet6 = mptcp_inet6_sk(nsk);
#endif
- nsk->sk_wait_pending = 0;
__mptcp_init_sock(nsk);
msk = mptcp_sk(nsk);
@@ -139,8 +139,8 @@ void update_sk_prot(struct sock *sk, struct tls_context *ctx)
int wait_on_pending_writer(struct sock *sk, long *timeo)
{
- int rc = 0;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
+ int ret, rc = 0;
add_wait_queue(sk_sleep(sk), &wait);
while (1) {
@@ -154,9 +154,13 @@ int wait_on_pending_writer(struct sock *sk, long *timeo)
break;
}
- if (sk_wait_event(sk, timeo,
- !READ_ONCE(sk->sk_write_pending), &wait))
+ ret = sk_wait_event(sk, timeo,
+ !READ_ONCE(sk->sk_write_pending), &wait);
+ if (ret) {
+ if (ret < 0)
+ rc = ret;
break;
+ }
}
remove_wait_queue(sk_sleep(sk), &wait);
return rc;
@@ -1291,6 +1291,7 @@ tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock,
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
DEFINE_WAIT_FUNC(wait, woken_wake_function);
+ int ret = 0;
long timeo;
timeo = sock_rcvtimeo(sk, nonblock);
@@ -1302,6 +1303,9 @@ tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock,
if (sk->sk_err)
return sock_error(sk);
+ if (ret < 0)
+ return ret;
+
if (!skb_queue_empty(&sk->sk_receive_queue)) {
tls_strp_check_rcv(&ctx->strp);
if (tls_strp_msg_ready(ctx))
@@ -1320,10 +1324,10 @@ tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock,
released = true;
add_wait_queue(sk_sleep(sk), &wait);
sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
- sk_wait_event(sk, &timeo,
- tls_strp_msg_ready(ctx) ||
- !sk_psock_queue_empty(psock),
- &wait);
+ ret = sk_wait_event(sk, &timeo,
+ tls_strp_msg_ready(ctx) ||
+ !sk_psock_queue_empty(psock),
+ &wait);
sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
remove_wait_queue(sk_sleep(sk), &wait);
@@ -1852,6 +1856,7 @@ static int tls_rx_reader_acquire(struct sock *sk, struct tls_sw_context_rx *ctx,
bool nonblock)
{
long timeo;
+ int ret;
timeo = sock_rcvtimeo(sk, nonblock);
@@ -1861,14 +1866,16 @@ static int tls_rx_reader_acquire(struct sock *sk, struct tls_sw_context_rx *ctx,
ctx->reader_contended = 1;
add_wait_queue(&ctx->wq, &wait);
- sk_wait_event(sk, &timeo,
- !READ_ONCE(ctx->reader_present), &wait);
+ ret = sk_wait_event(sk, &timeo,
+ !READ_ONCE(ctx->reader_present), &wait);
remove_wait_queue(&ctx->wq, &wait);
if (timeo <= 0)
return -EAGAIN;
if (signal_pending(current))
return sock_intr_errno(timeo);
+ if (ret < 0)
+ return ret;
}
WRITE_ONCE(ctx->reader_present, 1);
As reported by Tom, .NET and applications build on top of it rely on connect(AF_UNSPEC) to async cancel pending I/O operations on TCP socket. The blamed commit below caused a regression, as such cancellation can now fail. As suggested by Eric, this change addresses the problem explicitly causing blocking I/O operation to terminate immediately (with an error) when a concurrent disconnect() is executed. Instead of tracking the number of threads blocked on a given socket, track the number of disconnect() issued on such socket. If such counter changes after a blocking operation releasing and re-acquiring the socket lock, error out the current operation. Fixes: 4faeee0cf8a5 ("tcp: deny tcp_disconnect() when threads are waiting") Reported-by: Tom Deseyn <tdeseyn@redhat.com> Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1886305 Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- v1 -> v2: - move the sk_disconnects increment in __inet_stream_connect() (Eric) --- .../chelsio/inline_crypto/chtls/chtls_io.c | 36 +++++++++++++++---- include/net/sock.h | 10 +++--- net/core/stream.c | 12 ++++--- net/ipv4/af_inet.c | 10 ++++-- net/ipv4/inet_connection_sock.c | 1 - net/ipv4/tcp.c | 16 ++++----- net/ipv4/tcp_bpf.c | 4 +++ net/mptcp/protocol.c | 7 ---- net/tls/tls_main.c | 10 ++++-- net/tls/tls_sw.c | 19 ++++++---- 10 files changed, 80 insertions(+), 45 deletions(-)