On 3/3/23 13:18, Roberto Sassu wrote:
From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the inode_post_create_tmpfile hook.
Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
---
fs/namei.c | 1 +
include/linux/lsm_hook_defs.h | 2 ++
include/linux/security.h | 8 ++++++++
security/security.c | 18 ++++++++++++++++++
4 files changed, 29 insertions(+)
diff --git a/fs/namei.c b/fs/namei.c
index 3f2747521d3..8c4fdfd81d4 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3624,6 +3624,7 @@ static int vfs_tmpfile(struct mnt_idmap *idmap,
inode->i_state |= I_LINKABLE;
spin_unlock(&inode->i_lock);
}
+ security_inode_post_create_tmpfile(idmap, dir, file_dentry(file), mode);
ima_post_create_tmpfile(idmap, dir, file_dentry(file), mode);
return 0;
}
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 32c801a3ea2..5dc2a7c3d9a 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -120,6 +120,8 @@ LSM_HOOK(int, 0, inode_init_security_anon, struct inode *inode,
const struct qstr *name, const struct inode *context_inode)
LSM_HOOK(int, 0, inode_create, struct inode *dir, struct dentry *dentry,
umode_t mode)
+LSM_HOOK(void, LSM_RET_VOID, inode_post_create_tmpfile, struct mnt_idmap *idmap,
+ struct inode *dir, struct dentry *dentry, umode_t mode)
LSM_HOOK(int, 0, inode_link, struct dentry *old_dentry, struct inode *dir,
struct dentry *new_dentry)
LSM_HOOK(int, 0, inode_unlink, struct inode *dir, struct dentry *dentry)
diff --git a/include/linux/security.h b/include/linux/security.h
index fb6e9d434c6..b3e201404dc 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -337,6 +337,9 @@ int security_inode_init_security_anon(struct inode *inode,
const struct qstr *name,
const struct inode *context_inode);
int security_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode);
+void security_inode_post_create_tmpfile(struct mnt_idmap *idmap,
+ struct inode *dir,
+ struct dentry *dentry, umode_t mode);
int security_inode_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *new_dentry);
int security_inode_unlink(struct inode *dir, struct dentry *dentry);
@@ -787,6 +790,11 @@ static inline int security_inode_create(struct inode *dir,
return 0;
}
+static inline void
+security_inode_post_create_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
+ struct dentry *dentry, umode_t mode)
+{ }
+
static inline int security_inode_link(struct dentry *old_dentry,
struct inode *dir,
struct dentry *new_dentry)
diff --git a/security/security.c b/security/security.c
index f5f367e2064..8883082b686 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1971,6 +1971,24 @@ int security_inode_create(struct inode *dir, struct dentry *dentry,
}
EXPORT_SYMBOL_GPL(security_inode_create);
+/**
+ * security_inode_post_create_tmpfile() - Update inode sec after tmpfile created
'sec'? -> Update inode security field after creation of tmpfile
+ * @idmap: idmap of the mount
+ * @dir: the inode of the base directory
+ * @dentry: the dentry of the new tmpfile
+ * @mode: the mode of the new tmpfile
+ *
+ * Update inode security field after a tmpfile has been created.
With the nit above:
Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
+ */
+void security_inode_post_create_tmpfile(struct mnt_idmap *idmap,
+ struct inode *dir,
+ struct dentry *dentry, umode_t mode)
+{
+ if (unlikely(IS_PRIVATE(dir)))
+ return;
+ call_void_hook(inode_post_create_tmpfile, idmap, dir, dentry, mode);
+}
+
/**
* security_inode_link() - Check if creating a hard link is allowed
* @old_dentry: existing file
