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 4.9-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-4.9 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 Thu Dec 21 09:02:40 CET 2017 From: Alexander Duyck <alexander.h.duyck@xxxxxxxxx> 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@xxxxxxxxx> [ 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@xxxxxxxxx> Acked-by: Eric Dumazet <edumazet@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -369,14 +369,16 @@ 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@xxxxxxxxx are queue-4.9/i40e-do-not-enable-napi-on-q_vectors-that-have-no-rings.patch queue-4.9/net-do-not-allow-negative-values-for-busy_read-and-busy_poll-sysctl-interfaces.patch