@@ -615,6 +615,7 @@ struct kernfs_node *kernfs_node_from_dentry(struct dentry *dentry)
}
static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root,
+ struct kernfs_node *parent,
const char *name, umode_t mode,
kuid_t uid, kgid_t gid,
unsigned flags)
@@ -671,6 +672,12 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root,
goto err_out3;
}
+ if (parent) {
+ ret = security_kernfs_init_security(parent, kn);
+ if (ret)
+ goto err_out3;
+ }
+
return kn;
err_out3:
@@ -689,7 +696,7 @@ struct kernfs_node *kernfs_new_node(struct kernfs_node *parent,
{
struct kernfs_node *kn;
- kn = __kernfs_new_node(kernfs_root(parent),
+ kn = __kernfs_new_node(kernfs_root(parent), parent,
name, mode, uid, gid, flags);
if (kn) {
kernfs_get(parent);
@@ -958,7 +965,7 @@ struct kernfs_root *kernfs_create_root(struct kernfs_syscall_ops *scops,
INIT_LIST_HEAD(&root->supers);
root->next_generation = 1;
- kn = __kernfs_new_node(root, "", S_IFDIR | S_IRUGO | S_IXUGO,
+ kn = __kernfs_new_node(root, NULL, "", S_IFDIR | S_IRUGO | S_IXUGO,
GLOBAL_ROOT_UID, GLOBAL_ROOT_GID,
KERNFS_DIR);
if (!kn) {
Use the new security_kernfs_init_security() hook to allow LSMs to possibly assign a non-default security context to a newly created kernfs node based on the attributes of the new node and also its parent node. This fixes an issue with cgroupfs under SELinux, where newly created cgroup subdirectories/files would not inherit its parent's context if it had been set explicitly to a non-default value (other than the genfs context specified by the policy). This can be reproduced as follows (on Fedora/RHEL): # mkdir /sys/fs/cgroup/unified/test # # Need permissive to change the label under Fedora policy: # setenforce 0 # chcon -t container_file_t /sys/fs/cgroup/unified/test # ls -lZ /sys/fs/cgroup/unified total 0 -r--r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.controllers -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.max.depth -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.max.descendants -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.procs -r--r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.stat -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.subtree_control -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.threads drwxr-xr-x. 2 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 init.scope drwxr-xr-x. 26 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:21 system.slice drwxr-xr-x. 3 root root system_u:object_r:container_file_t:s0 0 Jan 29 03:15 test drwxr-xr-x. 3 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 user.slice # mkdir /sys/fs/cgroup/unified/test/subdir Actual result: # ls -ldZ /sys/fs/cgroup/unified/test/subdir drwxr-xr-x. 2 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:15 /sys/fs/cgroup/unified/test/subdir Expected result: # ls -ldZ /sys/fs/cgroup/unified/test/subdir drwxr-xr-x. 2 root root unconfined_u:object_r:container_file_t:s0 0 Jan 29 03:15 /sys/fs/cgroup/unified/test/subdir Link: https://github.com/SELinuxProject/selinux-kernel/issues/39 Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> --- fs/kernfs/dir.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)