[PATCH v2 17/25] security: Introduce inode_post_create_tmpfile hook
From: Roberto Sassu <hidden>
Date: 2023-08-31 10:47:46
Also in:
keyrings, linux-fsdevel, linux-integrity, linux-nfs, lkml, selinux
Subsystem:
filesystems (vfs and infrastructure), security subsystem, the rest · Maintainers:
Alexander Viro, Christian Brauner, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
From: Roberto Sassu <roberto.sassu@huawei.com> 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@huawei.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> --- 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 c8c4ab26b52a..efed0e1e93f5 100644
--- a/fs/namei.c
+++ b/fs/namei.c@@ -3700,6 +3700,7 @@ 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, mode); ima_post_create_tmpfile(idmap, dir, file, mode); return 0; }
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index b1634b5de98c..9ae573b83737 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h@@ -121,6 +121,8 @@ 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 file *file, 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 f210bd66e939..5f296761883f 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h@@ -338,6 +338,9 @@ 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 file *file, + 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);
@@ -788,6 +791,11 @@ 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 file *file, 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 56c1c1e66fd1..e5acb11f6ebd 100644
--- a/security/security.c
+++ b/security/security.c@@ -1920,6 +1920,24 @@ int security_inode_create(struct inode *dir, struct dentry *dentry, } EXPORT_SYMBOL_GPL(security_inode_create); +/** + * security_inode_post_create_tmpfile() - Update inode security field after creation of tmpfile + * @idmap: idmap of the mount + * @dir: the inode of the base directory + * @file: file descriptor of the new tmpfile + * @mode: the mode of the new tmpfile + * + * Update inode security field after a tmpfile has been created. + */ +void security_inode_post_create_tmpfile(struct mnt_idmap *idmap, + struct inode *dir, + struct file *file, umode_t mode) +{ + if (unlikely(IS_PRIVATE(dir))) + return; + call_void_hook(inode_post_create_tmpfile, idmap, dir, file, mode); +} + /** * security_inode_link() - Check if creating a hard link is allowed * @old_dentry: existing file
--
2.34.1