4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Myungho Jung <mhjungk@xxxxxxxxx> commit b94bf594cf8ed67cdd0439e70fa939783471597a upstream. timer_migration sysctl acts as a boolean switch, so the allowed values should be restricted to 0 and 1. Add the necessary extra fields to the sysctl table entry to enforce that. [ tglx: Rewrote changelog ] Signed-off-by: Myungho Jung <mhjungk@xxxxxxxxx> Link: http://lkml.kernel.org/r/1492640690-3550-1-git-send-email-mhjungk@xxxxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Kazuhiro Hayashi <kazuhiro3.hayashi@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/sysctl.c | 2 ++ kernel/time/timer.c | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1189,6 +1189,8 @@ static struct ctl_table kern_table[] = { .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = timer_migration_handler, + .extra1 = &zero, + .extra2 = &one, }, #endif #ifdef CONFIG_BPF_SYSCALL --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -240,7 +240,7 @@ int timer_migration_handler(struct ctl_t int ret; mutex_lock(&mutex); - ret = proc_dointvec(table, write, buffer, lenp, ppos); + ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); if (!ret && write) timers_update_migration(false); mutex_unlock(&mutex);