diff options
| -rw-r--r-- | kernel/sched.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index a3d1c8e43d34..d3d81b82e378 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3531,13 +3531,24 @@ recheck: if ((policy == SCHED_NORMAL) != (param->sched_priority == 0)) return -EINVAL; - if ((policy == SCHED_FIFO || policy == SCHED_RR) && - param->sched_priority > p->signal->rlim[RLIMIT_RTPRIO].rlim_cur && - !capable(CAP_SYS_NICE)) - return -EPERM; - if ((current->euid != p->euid) && (current->euid != p->uid) && - !capable(CAP_SYS_NICE)) - return -EPERM; + /* + * Allow unprivileged RT tasks to decrease priority: + */ + if (!capable(CAP_SYS_NICE)) { + /* can't change policy */ + if (policy != p->policy) + return -EPERM; + /* can't increase priority */ + if (policy != SCHED_NORMAL && + param->sched_priority > p->rt_priority && + param->sched_priority > + p->signal->rlim[RLIMIT_RTPRIO].rlim_cur) + return -EPERM; + /* can't change other user's priorities */ + if ((current->euid != p->euid) && + (current->euid != p->uid)) + return -EPERM; + } retval = security_task_setscheduler(p, policy, param); if (retval) |