[PATCH v4 4/8] fs: add anon_inode_getfile_secure() similar to anon_inode_getfd_secure()

Extending the secure anonymous inode support to other subsystems requires that we have a secure anon_inode_getfile() variant in addition to the existing secure anon_inode_getfd() variant. Thankfully we can reuse the existing __anon_inode_getfile() function and just wrap it with the proper arguments. Acked-by: Mickaël Salaün <mic(a)linux.microsoft.com&gt; Signed-off-by: Paul Moore <paul(a)paul-moore.com&gt; --- v4: - no change v3: - no change v2: - no change v1: - initial draft --- fs/anon_inodes.c | 29 +++++++++++++++++++++++++++++ include/linux/anon_inodes.h | 4 ++++ 2 files changed, 33 insertions(+) diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c index a280156138ed..e0c3e33c4177 100644 --- a/fs/anon_inodes.c +++ b/fs/anon_inodes.c @@ -148,6 +148,35 @@ struct file *anon_inode_getfile(const char *name, } EXPORT_SYMBOL_GPL(anon_inode_getfile); +/** + * anon_inode_getfile_secure - Like anon_inode_getfile(), but creates a new + * !S_PRIVATE anon inode rather than reuse the + * singleton anon inode and calls the + * inode_init_security_anon() LSM hook. This + * allows for both the inode to have its own + * security context and for the LSM to enforce + * policy on the inode's creation. + * + * @name: [in] name of the "class" of the new file + * @fops: [in] file operations for the new file + * @priv: [in] private data for the new file (will be file's private_data) + * @flags: [in] flags + * @context_inode: + * [in] the logical relationship with the new inode (optional) + * + * The LSM may use @context_inode in inode_init_security_anon(), but a + * reference to it is not held. Returns the newly created file* or an error + * pointer. See the anon_inode_getfile() documentation for more information. + */ +struct file *anon_inode_getfile_secure(const char *name, + const struct file_operations *fops, + void *priv, int flags, + const struct inode *context_inode) +{ + return __anon_inode_getfile(name, fops, priv, flags, + context_inode, true); +} + static int __anon_inode_getfd(const char *name, const struct file_operations *fops, void *priv, int flags, diff --git a/include/linux/anon_inodes.h b/include/linux/anon_inodes.h index 71881a2b6f78..5deaddbd7927 100644 --- a/include/linux/anon_inodes.h +++ b/include/linux/anon_inodes.h @@ -15,6 +15,10 @@ struct inode; struct file *anon_inode_getfile(const char *name, const struct file_operations *fops, void *priv, int flags); +struct file *anon_inode_getfile_secure(const char *name, + const struct file_operations *fops, + void *priv, int flags, + const struct inode *context_inode); int anon_inode_getfd(const char *name, const struct file_operations *fops, void *priv, int flags); int anon_inode_getfd_secure(const char *name,