diff options
| author |   Dhaval Giani <dhaval@linux.vnet.ibm.com> | 2009-02-27 15:13:54 +0530 |
|---|---|---|
| committer |   Ingo Molnar <mingo@elte.hu> | 2009-02-27 11:11:53 +0100 |
| commit | 54e991242850edc8c53f71fa5aa3ba7a93ce38f5 (patch) | |
| tree | 7f136214aab690a8ee4a294ca9c1a7e01de0dc49 /kernel/sched.c | |
| parent | sched_rt: don't start timer when rt bandwidth disabled (diff) | |
| download | linux-dev-54e991242850edc8c53f71fa5aa3ba7a93ce38f5.tar.xz linux-dev-54e991242850edc8c53f71fa5aa3ba7a93ce38f5.zip | |
sched: don't allow setuid to succeed if the user does not have rt bandwidth
Impact: fix hung task with certain (non-default) rt-limit settings
Corey Hickey reported that on using setuid to change the uid of a
rt process, the process would be unkillable and not be running.
This is because there was no rt runtime for that user group. Add
in a check to see if a user can attach an rt task to its task group.
On failure, return EINVAL, which is also returned in
CONFIG_CGROUP_SCHED.
Reported-by: Corey Hickey <bugfood-ml@fatooh.org>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index c3baa9653d1d..8e2558c2ba67 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -9224,6 +9224,16 @@ static int sched_rt_global_constraints(void) return ret; } + +int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) +{ + /* Don't accept realtime tasks when there is no way for them to run */ + if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) + return 0; + + return 1; +} + #else /* !CONFIG_RT_GROUP_SCHED */ static int sched_rt_global_constraints(void) { @@ -9317,8 +9327,7 @@ cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, struct task_struct *tsk) { #ifdef CONFIG_RT_GROUP_SCHED - /* Don't accept realtime tasks when there is no way for them to run */ - if (rt_task(tsk) && cgroup_tg(cgrp)->rt_bandwidth.rt_runtime == 0) + if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) return -EINVAL; #else /* We don't support RT-tasks being in separate groups */ |