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authorPaolo Abeni <pabeni@redhat.com>2022-06-27 18:02:38 -0700
committerJakub Kicinski <kuba@kernel.org>2022-06-28 20:45:42 -0700
commitd51991e2e31477853e5b9c1005ac617707077286 (patch)
treeb49c6d4c82eaf1dff520fecdd3caa84f60718956 /net/mptcp
parent76a13b315709b5b65a7b65caf9ede9a8a38d8930 (diff)
mptcp: fix shutdown vs fallback race
If the MPTCP socket shutdown happens before a fallback to TCP, and all the pending data have been already spooled, we never close the TCP connection. Address the issue explicitly checking for critical condition at fallback time. Fixes: 1e39e5a32ad7 ("mptcp: infinite mapping sending") Fixes: 0348c690ed37 ("mptcp: add the fallback check") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/mptcp')
-rw-r--r--net/mptcp/options.c2
-rw-r--r--net/mptcp/protocol.c2
-rw-r--r--net/mptcp/protocol.h19
-rw-r--r--net/mptcp/subflow.c2
4 files changed, 19 insertions, 6 deletions
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 2a6351d55a7d..aead331866a0 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -967,7 +967,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk,
goto reset;
subflow->mp_capable = 0;
pr_fallback(msk);
- __mptcp_do_fallback(msk);
+ mptcp_do_fallback(ssk);
return false;
}
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index e6fcb61443dd..e63bc2bb7fff 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1245,7 +1245,7 @@ static void mptcp_update_infinite_map(struct mptcp_sock *msk,
MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPTX);
mptcp_subflow_ctx(ssk)->send_infinite_map = 0;
pr_fallback(msk);
- __mptcp_do_fallback(msk);
+ mptcp_do_fallback(ssk);
}
static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 1d2d71711872..9860179bfd5e 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -927,12 +927,25 @@ static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
}
-static inline void mptcp_do_fallback(struct sock *sk)
+static inline void mptcp_do_fallback(struct sock *ssk)
{
- struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
- struct mptcp_sock *msk = mptcp_sk(subflow->conn);
+ struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
+ struct sock *sk = subflow->conn;
+ struct mptcp_sock *msk;
+ msk = mptcp_sk(sk);
__mptcp_do_fallback(msk);
+ if (READ_ONCE(msk->snd_data_fin_enable) && !(ssk->sk_shutdown & SEND_SHUTDOWN)) {
+ gfp_t saved_allocation = ssk->sk_allocation;
+
+ /* we are in a atomic (BH) scope, override ssk default for data
+ * fin allocation
+ */
+ ssk->sk_allocation = GFP_ATOMIC;
+ ssk->sk_shutdown |= SEND_SHUTDOWN;
+ tcp_shutdown(ssk, SEND_SHUTDOWN);
+ ssk->sk_allocation = saved_allocation;
+ }
}
#define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 8dfea6a8a82f..b34b96fb742f 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1279,7 +1279,7 @@ fallback:
return false;
}
- __mptcp_do_fallback(msk);
+ mptcp_do_fallback(ssk);
}
skb = skb_peek(&ssk->sk_receive_queue);