From mboxrd@z Thu Jan 1 00:00:00 1970 From: Prakash Sangappa Subject: [RESEND RFC PATCH 1/1] Selectively allow CAP_SYS_NICE capability inside user namespaces Date: Mon, 18 Nov 2019 09:01:18 -0800 Message-ID: <1574096478-11520-2-git-send-email-prakash.sangappa@oracle.com> References: <1574096478-11520-1-git-send-email-prakash.sangappa@oracle.com> Return-path: In-Reply-To: <1574096478-11520-1-git-send-email-prakash.sangappa@oracle.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org Cc: ebiederm@xmission.com, tglx@linutronix.de, peterz@infradead.org, serge@hallyn.com, prakash.sangappa@oracle.com List-Id: linux-api@vger.kernel.org Allow CAP_SYS_NICE to take effect for processes having effective uid of a root user from init namespace. Signed-off-by: Prakash Sangappa --- kernel/sched/core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 7880f4f..628bd46 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4548,6 +4548,8 @@ int can_nice(const struct task_struct *p, const int nice) int nice_rlim = nice_to_rlimit(nice); return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || + (ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE) && + uid_eq(current_euid(), GLOBAL_ROOT_UID)) || capable(CAP_SYS_NICE)); } @@ -4784,7 +4786,9 @@ static int __sched_setscheduler(struct task_struct *p, /* * Allow unprivileged RT tasks to decrease priority: */ - if (user && !capable(CAP_SYS_NICE)) { + if (user && !(ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE) && + uid_eq(current_euid(), GLOBAL_ROOT_UID)) && + !capable(CAP_SYS_NICE)) { if (fair_policy(policy)) { if (attr->sched_nice < task_nice(p) && !can_nice(p, attr->sched_nice)) -- 2.7.4