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| author | Paolo Abeni <pabeni@redhat.com> | 2024-12-30 19:12:31 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-01-03 03:44:03 +0100 |
| commit | 551844f26da2a9f76c0a698baaffa631d1178645 (patch) | |
| tree | 3077e1393ba2f7d3ce48590133e90e69aa366d3f /net | |
| parent | mptcp: fix recvbuffer adjust on sleeping rcvmsg (diff) | |
| download | linux-551844f26da2a9f76c0a698baaffa631d1178645.tar.xz linux-551844f26da2a9f76c0a698baaffa631d1178645.zip | |
mptcp: don't always assume copied data in mptcp_cleanup_rbuf()
Under some corner cases the MPTCP protocol can end-up invoking
mptcp_cleanup_rbuf() when no data has been copied, but such helper
assumes the opposite condition.
Explicitly drop such assumption and performs the costly call only
when strictly needed - before releasing the msk socket lock.
Fixes: fd8976790a6c ("mptcp: be careful on MPTCP-level ack.")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241230-net-mptcp-rbuf-fixes-v1-2-8608af434ceb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/mptcp/protocol.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 27afdb7e2071..5307fff9d995 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -528,13 +528,13 @@ static void mptcp_send_ack(struct mptcp_sock *msk) mptcp_subflow_send_ack(mptcp_subflow_tcp_sock(subflow)); } -static void mptcp_subflow_cleanup_rbuf(struct sock *ssk) +static void mptcp_subflow_cleanup_rbuf(struct sock *ssk, int copied) { bool slow; slow = lock_sock_fast(ssk); if (tcp_can_send_ack(ssk)) - tcp_cleanup_rbuf(ssk, 1); + tcp_cleanup_rbuf(ssk, copied); unlock_sock_fast(ssk, slow); } @@ -551,7 +551,7 @@ static bool mptcp_subflow_could_cleanup(const struct sock *ssk, bool rx_empty) (ICSK_ACK_PUSHED2 | ICSK_ACK_PUSHED))); } -static void mptcp_cleanup_rbuf(struct mptcp_sock *msk) +static void mptcp_cleanup_rbuf(struct mptcp_sock *msk, int copied) { int old_space = READ_ONCE(msk->old_wspace); struct mptcp_subflow_context *subflow; @@ -559,14 +559,14 @@ static void mptcp_cleanup_rbuf(struct mptcp_sock *msk) int space = __mptcp_space(sk); bool cleanup, rx_empty; - cleanup = (space > 0) && (space >= (old_space << 1)); - rx_empty = !__mptcp_rmem(sk); + cleanup = (space > 0) && (space >= (old_space << 1)) && copied; + rx_empty = !__mptcp_rmem(sk) && copied; mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); if (cleanup || mptcp_subflow_could_cleanup(ssk, rx_empty)) - mptcp_subflow_cleanup_rbuf(ssk); + mptcp_subflow_cleanup_rbuf(ssk, copied); } } @@ -2220,9 +2220,6 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, copied += bytes_read; - /* be sure to advertise window change */ - mptcp_cleanup_rbuf(msk); - if (skb_queue_empty(&msk->receive_queue) && __mptcp_move_skbs(msk)) continue; @@ -2271,6 +2268,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, } pr_debug("block timeout %ld\n", timeo); + mptcp_cleanup_rbuf(msk, copied); err = sk_wait_data(sk, &timeo, NULL); if (err < 0) { err = copied ? : err; @@ -2278,6 +2276,8 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, } } + mptcp_cleanup_rbuf(msk, copied); + out_err: if (cmsg_flags && copied >= 0) { if (cmsg_flags & MPTCP_CMSG_TS) |