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-rw-r--r--kernel/cgroup/cgroup-v1.c14
-rw-r--r--kernel/cgroup/cgroup.c11
-rw-r--r--kernel/cgroup/cpuset.c65
3 files changed, 73 insertions, 17 deletions
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 41e0837a5a0b..0e877dbcfeea 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -549,6 +549,14 @@ static ssize_t cgroup_release_agent_write(struct kernfs_open_file *of,
BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX);
+ /*
+ * Release agent gets called with all capabilities,
+ * require capabilities to set release agent.
+ */
+ if ((of->file->f_cred->user_ns != &init_user_ns) ||
+ !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
cgrp = cgroup_kn_lock_live(of->kn, false);
if (!cgrp)
return -ENODEV;
@@ -954,6 +962,12 @@ int cgroup1_parse_param(struct fs_context *fc, struct fs_parameter *param)
/* Specifying two release agents is forbidden */
if (ctx->release_agent)
return invalfc(fc, "release_agent respecified");
+ /*
+ * Release agent gets called with all capabilities,
+ * require capabilities to set release agent.
+ */
+ if ((fc->user_ns != &init_user_ns) || !capable(CAP_SYS_ADMIN))
+ return invalfc(fc, "Setting release_agent not allowed");
ctx->release_agent = param->string;
param->string = NULL;
break;
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index b31e1465868a..9d05c3ca2d5e 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -3643,6 +3643,12 @@ static ssize_t cgroup_pressure_write(struct kernfs_open_file *of, char *buf,
cgroup_get(cgrp);
cgroup_kn_unlock(of->kn);
+ /* Allow only one trigger per file descriptor */
+ if (ctx->psi.trigger) {
+ cgroup_put(cgrp);
+ return -EBUSY;
+ }
+
psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
new = psi_trigger_create(psi, buf, nbytes, res);
if (IS_ERR(new)) {
@@ -3650,8 +3656,7 @@ static ssize_t cgroup_pressure_write(struct kernfs_open_file *of, char *buf,
return PTR_ERR(new);
}
- psi_trigger_replace(&ctx->psi.trigger, new);
-
+ smp_store_release(&ctx->psi.trigger, new);
cgroup_put(cgrp);
return nbytes;
@@ -3690,7 +3695,7 @@ static void cgroup_pressure_release(struct kernfs_open_file *of)
{
struct cgroup_file_ctx *ctx = of->priv;
- psi_trigger_replace(&ctx->psi.trigger, NULL);
+ psi_trigger_destroy(ctx->psi.trigger);
}
bool cgroup_psi_enabled(void)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index e4e18a2cb404..721325e3fa23 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -591,6 +591,35 @@ static inline void free_cpuset(struct cpuset *cs)
}
/*
+ * validate_change_legacy() - Validate conditions specific to legacy (v1)
+ * behavior.
+ */
+static int validate_change_legacy(struct cpuset *cur, struct cpuset *trial)
+{
+ struct cgroup_subsys_state *css;
+ struct cpuset *c, *par;
+ int ret;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ /* Each of our child cpusets must be a subset of us */
+ ret = -EBUSY;
+ cpuset_for_each_child(c, css, cur)
+ if (!is_cpuset_subset(c, trial))
+ goto out;
+
+ /* On legacy hierarchy, we must be a subset of our parent cpuset. */
+ ret = -EACCES;
+ par = parent_cs(cur);
+ if (par && !is_cpuset_subset(trial, par))
+ goto out;
+
+ ret = 0;
+out:
+ return ret;
+}
+
+/*
* validate_change() - Used to validate that any proposed cpuset change
* follows the structural rules for cpusets.
*
@@ -614,20 +643,21 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
{
struct cgroup_subsys_state *css;
struct cpuset *c, *par;
- int ret;
-
- /* The checks don't apply to root cpuset */
- if (cur == &top_cpuset)
- return 0;
+ int ret = 0;
rcu_read_lock();
- par = parent_cs(cur);
- /* On legacy hierarchy, we must be a subset of our parent cpuset. */
- ret = -EACCES;
- if (!is_in_v2_mode() && !is_cpuset_subset(trial, par))
+ if (!is_in_v2_mode())
+ ret = validate_change_legacy(cur, trial);
+ if (ret)
+ goto out;
+
+ /* Remaining checks don't apply to root cpuset */
+ if (cur == &top_cpuset)
goto out;
+ par = parent_cs(cur);
+
/*
* If either I or some sibling (!= me) is exclusive, we can't
* overlap
@@ -1175,9 +1205,7 @@ enum subparts_cmd {
*
* Because of the implicit cpu exclusive nature of a partition root,
* cpumask changes that violates the cpu exclusivity rule will not be
- * permitted when checked by validate_change(). The validate_change()
- * function will also prevent any changes to the cpu list if it is not
- * a superset of children's cpu lists.
+ * permitted when checked by validate_change().
*/
static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd,
struct cpumask *newmask,
@@ -1522,10 +1550,15 @@ static void update_sibling_cpumasks(struct cpuset *parent, struct cpuset *cs,
struct cpuset *sibling;
struct cgroup_subsys_state *pos_css;
+ percpu_rwsem_assert_held(&cpuset_rwsem);
+
/*
* Check all its siblings and call update_cpumasks_hier()
* if their use_parent_ecpus flag is set in order for them
* to use the right effective_cpus value.
+ *
+ * The update_cpumasks_hier() function may sleep. So we have to
+ * release the RCU read lock before calling it.
*/
rcu_read_lock();
cpuset_for_each_child(sibling, pos_css, parent) {
@@ -1533,8 +1566,13 @@ static void update_sibling_cpumasks(struct cpuset *parent, struct cpuset *cs,
continue;
if (!sibling->use_parent_ecpus)
continue;
+ if (!css_tryget_online(&sibling->css))
+ continue;
+ rcu_read_unlock();
update_cpumasks_hier(sibling, tmp);
+ rcu_read_lock();
+ css_put(&sibling->css);
}
rcu_read_unlock();
}
@@ -1607,8 +1645,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
* Make sure that subparts_cpus is a subset of cpus_allowed.
*/
if (cs->nr_subparts_cpus) {
- cpumask_andnot(cs->subparts_cpus, cs->subparts_cpus,
- cs->cpus_allowed);
+ cpumask_and(cs->subparts_cpus, cs->subparts_cpus, cs->cpus_allowed);
cs->nr_subparts_cpus = cpumask_weight(cs->subparts_cpus);
}
spin_unlock_irq(&callback_lock);