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-rw-r--r--kernel/cgroup/cgroup-internal.h2
-rw-r--r--kernel/cgroup/cgroup.c28
2 files changed, 21 insertions, 9 deletions
diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h
index cf637bc4ab45..6e36e854b512 100644
--- a/kernel/cgroup/cgroup-internal.h
+++ b/kernel/cgroup/cgroup-internal.h
@@ -68,6 +68,8 @@ static inline struct cgroup_fs_context *cgroup_fc2context(struct fs_context *fc)
struct cgroup_pidlist;
struct cgroup_file_ctx {
+ struct cgroup_namespace *ns;
+
struct {
void *trigger;
} psi;
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index a84631d08d98..cafb8c114a21 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -3822,14 +3822,19 @@ static int cgroup_file_open(struct kernfs_open_file *of)
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
+
+ ctx->ns = current->nsproxy->cgroup_ns;
+ get_cgroup_ns(ctx->ns);
of->priv = ctx;
if (!cft->open)
return 0;
ret = cft->open(of);
- if (ret)
+ if (ret) {
+ put_cgroup_ns(ctx->ns);
kfree(ctx);
+ }
return ret;
}
@@ -3840,13 +3845,14 @@ static void cgroup_file_release(struct kernfs_open_file *of)
if (cft->release)
cft->release(of);
+ put_cgroup_ns(ctx->ns);
kfree(ctx);
}
static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf,
size_t nbytes, loff_t off)
{
- struct cgroup_namespace *ns = current->nsproxy->cgroup_ns;
+ struct cgroup_file_ctx *ctx = of->priv;
struct cgroup *cgrp = of->kn->parent->priv;
struct cftype *cft = of_cft(of);
struct cgroup_subsys_state *css;
@@ -3863,7 +3869,7 @@ static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf,
*/
if ((cgrp->root->flags & CGRP_ROOT_NS_DELEGATE) &&
!(cft->flags & CFTYPE_NS_DELEGATABLE) &&
- ns != &init_cgroup_ns && ns->root_cset->dfl_cgrp == cgrp)
+ ctx->ns != &init_cgroup_ns && ctx->ns->root_cset->dfl_cgrp == cgrp)
return -EPERM;
if (cft->write)
@@ -4853,9 +4859,9 @@ static int cgroup_may_write(const struct cgroup *cgrp, struct super_block *sb)
static int cgroup_procs_write_permission(struct cgroup *src_cgrp,
struct cgroup *dst_cgrp,
- struct super_block *sb)
+ struct super_block *sb,
+ struct cgroup_namespace *ns)
{
- struct cgroup_namespace *ns = current->nsproxy->cgroup_ns;
struct cgroup *com_cgrp = src_cgrp;
int ret;
@@ -4884,11 +4890,12 @@ static int cgroup_procs_write_permission(struct cgroup *src_cgrp,
static int cgroup_attach_permissions(struct cgroup *src_cgrp,
struct cgroup *dst_cgrp,
- struct super_block *sb, bool threadgroup)
+ struct super_block *sb, bool threadgroup,
+ struct cgroup_namespace *ns)
{
int ret = 0;
- ret = cgroup_procs_write_permission(src_cgrp, dst_cgrp, sb);
+ ret = cgroup_procs_write_permission(src_cgrp, dst_cgrp, sb, ns);
if (ret)
return ret;
@@ -4905,6 +4912,7 @@ static int cgroup_attach_permissions(struct cgroup *src_cgrp,
static ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf,
bool threadgroup)
{
+ struct cgroup_file_ctx *ctx = of->priv;
struct cgroup *src_cgrp, *dst_cgrp;
struct task_struct *task;
const struct cred *saved_cred;
@@ -4932,7 +4940,8 @@ static ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf,
*/
saved_cred = override_creds(of->file->f_cred);
ret = cgroup_attach_permissions(src_cgrp, dst_cgrp,
- of->file->f_path.dentry->d_sb, threadgroup);
+ of->file->f_path.dentry->d_sb,
+ threadgroup, ctx->ns);
revert_creds(saved_cred);
if (ret)
goto out_finish;
@@ -6152,7 +6161,8 @@ static int cgroup_css_set_fork(struct kernel_clone_args *kargs)
goto err;
ret = cgroup_attach_permissions(cset->dfl_cgrp, dst_cgrp, sb,
- !(kargs->flags & CLONE_THREAD));
+ !(kargs->flags & CLONE_THREAD),
+ current->nsproxy->cgroup_ns);
if (ret)
goto err;