This is a note to let you know that I've just added the patch titled

tcp_nv: fix division by zero in tcpnv_acked()

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: tcp_nv-fix-division-by-zero-in-tcpnv_acked.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Tue Nov 21 13:08:13 CET 2017

From: Konstantin Khlebnikov khlebnikov@yandex-team.ru Date: Wed, 1 Nov 2017 16:32:15 +0300 Subject: tcp_nv: fix division by zero in tcpnv_acked()

From: Konstantin Khlebnikov khlebnikov@yandex-team.ru

[ Upstream commit 4eebff27ca4182bbf5f039dd60d79e2d7c0a707e ]

Average RTT could become zero. This happened in real life at least twice. This patch treats zero as 1us.

Signed-off-by: Konstantin Khlebnikov khlebnikov@yandex-team.ru Acked-by: Lawrence Brakmo Brakmo@fb.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/tcp_nv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ipv4/tcp_nv.c +++ b/net/ipv4/tcp_nv.c @@ -263,7 +263,7 @@ static void tcpnv_acked(struct sock *sk,

/* rate in 100's bits per second */ rate64 = ((u64)sample->in_flight) * 8000000; - rate = (u32)div64_u64(rate64, (u64)(avg_rtt * 100)); + rate = (u32)div64_u64(rate64, (u64)(avg_rtt ?: 1) * 100);

/* Remember the maximum rate seen during this RTT * Note: It may be more than one RTT. This function should be

Patches currently in stable-queue which might be from khlebnikov@yandex-team.ru are

queue-4.9/tcp_nv-fix-division-by-zero-in-tcpnv_acked.patch