| Message ID | 20230831104136.903180-18-roberto.sassu@huaweicloud.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | security: Move IMA and EVM to the LSM infrastructure | expand |
On 8/31/2023 3:41 AM, Roberto Sassu wrote: > 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. Repeat of new LSM hook general comment: Would you please include some explanation of how an LSM would use this hook? You might start with a description of how it is used in IMA/EVM, and why that could be generally useful. > > 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
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