[PATCH 2/2] sched: Don't report SCHED_FLAG_SUGOV in sched_getattr()

From: Quentin Perret
Date: Tue Jul 27 2021 - 06:11:18 EST


SCHED_FLAG_SUGOV is supposed to be a kernel-only flag that userspace
cannot interact with. However, sched_getattr() currently reports it
in sched_flags if called on a sugov worker even though it is not
actually defined in a UAPI header. To avoid this, make sure to
clean-up the sched_flags field in sched_getattr() before returning to
userspace.

Signed-off-by: Quentin Perret <qperret@xxxxxxxxxx>
---
kernel/sched/core.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 2d9ff40f4661..d8f489dcc383 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7535,6 +7535,7 @@ SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr,
kattr.sched_priority = p->rt_priority;
else
kattr.sched_nice = task_nice(p);
+ kattr.sched_flags &= SCHED_FLAG_ALL;

#ifdef CONFIG_UCLAMP_TASK
/*
--
2.32.0.432.gabb21c7263-goog