Patch "net: Do not allow negative values for busy_read and busy_poll sysctl interfaces" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

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

    net: Do not allow negative values for busy_read and busy_poll sysctl interfaces

to the 4.4-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:
     net-do-not-allow-negative-values-for-busy_read-and-busy_poll-sysctl-interfaces.patch
and it can be found in the queue-4.4 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 Thu Dec 21 10:35:49 CET 2017
From: Alexander Duyck <alexander.h.duyck@intel.com>
Date: Fri, 24 Mar 2017 09:38:03 -0700
Subject: net: Do not allow negative values for busy_read and busy_poll sysctl interfaces

From: Alexander Duyck <alexander.h.duyck@intel.com>


[ Upstream commit 95f255211396958c718aef8c45e3923b5211ea7b ]

This change basically codifies what I think was already the limitations on
the busy_poll and busy_read sysctl interfaces.  We weren't checking the
lower bounds and as such could input negative values. The behavior when
that was used was dependent on the architecture. In order to prevent any
issues with that I am just disabling support for values less than 0 since
this way we don't have to worry about any odd behaviors.

By limiting the sysctl values this way it also makes it consistent with how
we handle the SO_BUSY_POLL socket option since the value appears to be
reported as a signed integer value and negative values are rejected.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/core/sysctl_net_core.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c
@@ -360,14 +360,16 @@ static struct ctl_table net_core_table[]
 		.data		= &sysctl_net_busy_poll,
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &zero,
 	},
 	{
 		.procname	= "busy_read",
 		.data		= &sysctl_net_busy_read,
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &zero,
 	},
 #endif
 #ifdef CONFIG_NET_SCHED


Patches currently in stable-queue which might be from alexander.h.duyck@intel.com are

queue-4.4/i40e-do-not-enable-napi-on-q_vectors-that-have-no-rings.patch
queue-4.4/net-do-not-allow-negative-values-for-busy_read-and-busy_poll-sysctl-interfaces.patch