This is a note to let you know that I've just added the patch titled
mptcp: free acked data before waiting for more memory
to the 5.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mptcp-free-acked-data-before-waiting-for-more-memory.patch
and it can be found in the queue-5.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Fri Sep 11 09:06:46 AM CEST 2020
From: Florian Westphal <fw@xxxxxxxxx>
Date: Wed, 26 Aug 2020 01:31:05 +0200
Subject: mptcp: free acked data before waiting for more memory
From: Florian Westphal <fw@xxxxxxxxx>
[ Upstream commit 1cec170d458b1d18f6f1654ca84c0804a701c5ef ]
After subflow lock is dropped, more wmem might have been made available.
This fixes a deadlock in mptcp_connect.sh 'mmap' mode: wmem is exhausted.
But as the mptcp socket holds on to already-acked data (for retransmit)
no wakeup will occur.
Using 'goto restart' calls mptcp_clean_una(sk) which will free pages
that have been acked completely in the mean time.
Fixes: fb529e62d3f3 ("mptcp: break and restart in case mptcp sndbuf is full")
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/mptcp/protocol.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -772,7 +772,6 @@ fallback:
restart:
mptcp_clean_una(sk);
-wait_for_sndbuf:
__mptcp_flush_join_list(msk);
ssk = mptcp_subflow_get_send(msk);
while (!sk_stream_memory_free(sk) ||
@@ -873,7 +872,7 @@ wait_for_sndbuf:
*/
mptcp_set_timeout(sk, ssk);
release_sock(ssk);
- goto wait_for_sndbuf;
+ goto restart;
}
}
}
Patches currently in stable-queue which might be from fw@xxxxxxxxx are
queue-5.8/mptcp-free-acked-data-before-waiting-for-more-memory.patch
