Create a security context for the inodes created by memfd_secret(2) via
the LSM hook inode_init_security_anon to allow a fine grained control.
As secret memory areas can affect hibernation and have a global shared
limit access control might be desirable.
Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
An alternative way of checking memfd_secret(2) is to create a new LSM
hook and e.g. for SELinux check via a new process class permission.
---
mm/secretmem.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/mm/secretmem.c b/mm/secretmem.c
index 22b310adb53d..b61cd2f661bc 100644
--- a/mm/secretmem.c
+++ b/mm/secretmem.c
@@ -164,11 +164,20 @@ static struct file *secretmem_file_create(unsigned long flags)
{
struct file *file = ERR_PTR(-ENOMEM);
struct inode *inode;
+ const char *anon_name = "[secretmem]";
+ const struct qstr qname = QSTR_INIT(anon_name, strlen(anon_name));
+ int err;
inode = alloc_anon_inode(secretmem_mnt->mnt_sb);
if (IS_ERR(inode))
return ERR_CAST(inode);
+ err = security_inode_init_security_anon(inode, &qname, NULL);
+ if (err) {
+ file = ERR_PTR(err);
+ goto err_free_inode;
+ }
+
file = alloc_file_pseudo(inode, secretmem_mnt, "secretmem",
O_RDWR, &secretmem_fops);
if (IS_ERR(file))
--
2.34.1
