4.4-stable review patch. If anyone has any objections, please let me know.
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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