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Commit 05016b0f authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 

Pull getname/putname updates from Al Viro:
 "Rework of getname/getname_kernel/etc., mostly from Paul Moore.  Gets
  rid of quite a pile of kludges between namei and audit..."

* 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  audit: replace getname()/putname() hacks with reference counters
  audit: fix filename matching in __audit_inode() and __audit_inode_child()
  audit: enable filename recording via getname_kernel()
  simpler calling conventions for filename_mountpoint()
  fs: create proper filename objects using getname_kernel()
  fs: rework getname_kernel to handle up to PATH_MAX sized filenames
  cut down the number of do_path_lookup() callers
parents c6b1de1b 55422d0b

fs/exec.c

+8 −2
Original line number Diff line number Diff line
@@ -794,8 +794,14 @@ static struct file *do_open_execat(int fd, struct filename *name, int flags) 


struct file *open_exec(const char *name)

{

	struct filename tmp = { .name = name };

	return do_open_execat(AT_FDCWD, &tmp, 0);

	struct filename *filename = getname_kernel(name);

	struct file *f = ERR_CAST(filename);



	if (!IS_ERR(filename)) {

		f = do_open_execat(AT_FDCWD, filename, 0);

		putname(filename);

	}

	return f;

}

EXPORT_SYMBOL(open_exec);

fs/namei.c

+90 −53
Original line number Diff line number Diff line
@@ -118,15 +118,6 @@ 
 * POSIX.1 2.4: an empty pathname is invalid (ENOENT).

 * PATH_MAX includes the nul terminator --RR.

 */

void final_putname(struct filename *name)

{

	if (name->separate) {

		__putname(name->name);

		kfree(name);

	} else {

		__putname(name);

	}

}



#define EMBEDDED_NAME_MAX	(PATH_MAX - sizeof(struct filename))
@@ -145,6 +136,7 @@ getname_flags(const char __user *filename, int flags, int *empty) 
	result = __getname();

	if (unlikely(!result))

		return ERR_PTR(-ENOMEM);

	result->refcnt = 1;



	/*

	 * First, try to embed the struct filename inside the names_cache
@@ -179,6 +171,7 @@ getname_flags(const char __user *filename, int flags, int *empty) 
		}

		result->name = kname;

		result->separate = true;

		result->refcnt = 1;

		max = PATH_MAX;

		goto recopy;

	}
@@ -202,7 +195,7 @@ getname_flags(const char __user *filename, int flags, int *empty) 
	return result;



error:

	final_putname(result);

	putname(result);

	return err;

}
@@ -212,43 +205,56 @@ getname(const char __user * filename) 
	return getname_flags(filename, 0, NULL);

}



/*

 * The "getname_kernel()" interface doesn't do pathnames longer

 * than EMBEDDED_NAME_MAX. Deal with it - you're a kernel user.

 */

struct filename *

getname_kernel(const char * filename)

{

	struct filename *result;

	char *kname;

	int len;



	len = strlen(filename);

	if (len >= EMBEDDED_NAME_MAX)

		return ERR_PTR(-ENAMETOOLONG);

	int len = strlen(filename) + 1;



	result = __getname();

	if (unlikely(!result))

		return ERR_PTR(-ENOMEM);



	kname = (char *)result + sizeof(*result);

	result->name = kname;

	if (len <= EMBEDDED_NAME_MAX) {

		result->name = (char *)(result) + sizeof(*result);

		result->separate = false;

	} else if (len <= PATH_MAX) {

		struct filename *tmp;



		tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);

		if (unlikely(!tmp)) {

			__putname(result);

			return ERR_PTR(-ENOMEM);

		}

		tmp->name = (char *)result;

		tmp->separate = true;

		result = tmp;

	} else {

		__putname(result);

		return ERR_PTR(-ENAMETOOLONG);

	}

	memcpy((char *)result->name, filename, len);

	result->uptr = NULL;

	result->aname = NULL;

	result->separate = false;

	result->refcnt = 1;

	audit_getname(result);



	strlcpy(kname, filename, EMBEDDED_NAME_MAX);

	return result;

}



#ifdef CONFIG_AUDITSYSCALL

void putname(struct filename *name)

{

	if (unlikely(!audit_dummy_context()))

		return audit_putname(name);

	final_putname(name);

	BUG_ON(name->refcnt <= 0);



	if (--name->refcnt > 0)

		return;



	if (name->separate) {

		__putname(name->name);

		kfree(name);

	} else

		__putname(name);

}

#endif



static int check_acl(struct inode *inode, int mask)

{
@@ -2036,31 +2042,47 @@ static int filename_lookup(int dfd, struct filename *name, 
static int do_path_lookup(int dfd, const char *name,

				unsigned int flags, struct nameidata *nd)

{

	struct filename filename = { .name = name };

	struct filename *filename = getname_kernel(name);

	int retval = PTR_ERR(filename);



	return filename_lookup(dfd, &filename, flags, nd);

	if (!IS_ERR(filename)) {

		retval = filename_lookup(dfd, filename, flags, nd);

		putname(filename);

	}

	return retval;

}



/* does lookup, returns the object with parent locked */

struct dentry *kern_path_locked(const char *name, struct path *path)

{

	struct filename *filename = getname_kernel(name);

	struct nameidata nd;

	struct dentry *d;

	int err = do_path_lookup(AT_FDCWD, name, LOOKUP_PARENT, &nd);

	if (err)

		return ERR_PTR(err);

	int err;



	if (IS_ERR(filename))

		return ERR_CAST(filename);



	err = filename_lookup(AT_FDCWD, filename, LOOKUP_PARENT, &nd);

	if (err) {

		d = ERR_PTR(err);

		goto out;

	}

	if (nd.last_type != LAST_NORM) {

		path_put(&nd.path);

		return ERR_PTR(-EINVAL);

		d = ERR_PTR(-EINVAL);

		goto out;

	}

	mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);

	d = __lookup_hash(&nd.last, nd.path.dentry, 0);

	if (IS_ERR(d)) {

		mutex_unlock(&nd.path.dentry->d_inode->i_mutex);

		path_put(&nd.path);

		return d;

		goto out;

	}

	*path = nd.path;

out:

	putname(filename);

	return d;

}
@@ -2351,13 +2373,17 @@ static int 
filename_mountpoint(int dfd, struct filename *s, struct path *path,

			unsigned int flags)

{

	int error = path_mountpoint(dfd, s->name, path, flags | LOOKUP_RCU);

	int error;

	if (IS_ERR(s))

		return PTR_ERR(s);

	error = path_mountpoint(dfd, s->name, path, flags | LOOKUP_RCU);

	if (unlikely(error == -ECHILD))

		error = path_mountpoint(dfd, s->name, path, flags);

	if (unlikely(error == -ESTALE))

		error = path_mountpoint(dfd, s->name, path, flags | LOOKUP_REVAL);

	if (likely(!error))

		audit_inode(s, path->dentry, 0);

	putname(s);

	return error;

}
@@ -2379,21 +2405,14 @@ int 
user_path_mountpoint_at(int dfd, const char __user *name, unsigned int flags,

			struct path *path)

{

	struct filename *s = getname(name);

	int error;

	if (IS_ERR(s))

		return PTR_ERR(s);

	error = filename_mountpoint(dfd, s, path, flags);

	putname(s);

	return error;

	return filename_mountpoint(dfd, getname(name), path, flags);

}



int

kern_path_mountpoint(int dfd, const char *name, struct path *path,

			unsigned int flags)

{

	struct filename s = {.name = name};

	return filename_mountpoint(dfd, &s, path, flags);

	return filename_mountpoint(dfd, getname_kernel(name), path, flags);

}

EXPORT_SYMBOL(kern_path_mountpoint);
@@ -3273,7 +3292,7 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt, 
{

	struct nameidata nd;

	struct file *file;

	struct filename filename = { .name = name };

	struct filename *filename;

	int flags = op->lookup_flags | LOOKUP_ROOT;



	nd.root.mnt = mnt;
@@ -3282,15 +3301,20 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt, 
	if (d_is_symlink(dentry) && op->intent & LOOKUP_OPEN)

		return ERR_PTR(-ELOOP);



	file = path_openat(-1, &filename, &nd, op, flags | LOOKUP_RCU);

	filename = getname_kernel(name);

	if (unlikely(IS_ERR(filename)))

		return ERR_CAST(filename);



	file = path_openat(-1, filename, &nd, op, flags | LOOKUP_RCU);

	if (unlikely(file == ERR_PTR(-ECHILD)))

		file = path_openat(-1, &filename, &nd, op, flags);

		file = path_openat(-1, filename, &nd, op, flags);

	if (unlikely(file == ERR_PTR(-ESTALE)))

		file = path_openat(-1, &filename, &nd, op, flags | LOOKUP_REVAL);

		file = path_openat(-1, filename, &nd, op, flags | LOOKUP_REVAL);

	putname(filename);

	return file;

}



struct dentry *kern_path_create(int dfd, const char *pathname,

static struct dentry *filename_create(int dfd, struct filename *name,

				struct path *path, unsigned int lookup_flags)

{

	struct dentry *dentry = ERR_PTR(-EEXIST);
@@ -3305,7 +3329,7 @@ struct dentry *kern_path_create(int dfd, const char *pathname, 
	 */

	lookup_flags &= LOOKUP_REVAL;



	error = do_path_lookup(dfd, pathname, LOOKUP_PARENT|lookup_flags, &nd);

	error = filename_lookup(dfd, name, LOOKUP_PARENT|lookup_flags, &nd);

	if (error)

		return ERR_PTR(error);
@@ -3359,6 +3383,19 @@ struct dentry *kern_path_create(int dfd, const char *pathname, 
	path_put(&nd.path);

	return dentry;

}



struct dentry *kern_path_create(int dfd, const char *pathname,

				struct path *path, unsigned int lookup_flags)

{

	struct filename *filename = getname_kernel(pathname);

	struct dentry *res;



	if (IS_ERR(filename))

		return ERR_CAST(filename);

	res = filename_create(dfd, filename, path, lookup_flags);

	putname(filename);

	return res;

}

EXPORT_SYMBOL(kern_path_create);



void done_path_create(struct path *path, struct dentry *dentry)
@@ -3377,7 +3414,7 @@ struct dentry *user_path_create(int dfd, const char __user *pathname, 
	struct dentry *res;

	if (IS_ERR(tmp))

		return ERR_CAST(tmp);

	res = kern_path_create(dfd, tmp->name, path, lookup_flags);

	res = filename_create(dfd, tmp, path, lookup_flags);

	putname(tmp);

	return res;

}

fs/open.c

+8 −2
Original line number Diff line number Diff line
@@ -968,8 +968,14 @@ struct file *file_open_name(struct filename *name, int flags, umode_t mode) 
 */

struct file *filp_open(const char *filename, int flags, umode_t mode)

{

	struct filename name = {.name = filename};

	return file_open_name(&name, flags, mode);

	struct filename *name = getname_kernel(filename);

	struct file *file = ERR_CAST(name);

	

	if (!IS_ERR(name)) {

		file = file_open_name(name, flags, mode);

		putname(name);

	}

	return file;

}

EXPORT_SYMBOL(filp_open);

include/linux/audit.h

+0 −3
Original line number Diff line number Diff line
@@ -127,7 +127,6 @@ extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1, 
extern void __audit_syscall_exit(int ret_success, long ret_value);

extern struct filename *__audit_reusename(const __user char *uptr);

extern void __audit_getname(struct filename *name);

extern void audit_putname(struct filename *name);



#define AUDIT_INODE_PARENT	1	/* dentry represents the parent */

#define AUDIT_INODE_HIDDEN	2	/* audit record should be hidden */
@@ -352,8 +351,6 @@ static inline struct filename *audit_reusename(const __user char *name) 
}

static inline void audit_getname(struct filename *name)

{ }

static inline void audit_putname(struct filename *name)

{ }

static inline void __audit_inode(struct filename *name,

					const struct dentry *dentry,

					unsigned int flags)

include/linux/fs.h

+2 −7
Original line number Diff line number Diff line
@@ -2141,6 +2141,7 @@ struct filename { 
	const char		*name;	/* pointer to actual string */

	const __user char	*uptr;	/* original userland pointer */

	struct audit_names	*aname;

	int			refcnt;

	bool			separate; /* should "name" be freed? */

};
@@ -2162,6 +2163,7 @@ extern int filp_close(struct file *, fl_owner_t id); 
extern struct filename *getname_flags(const char __user *, int, int *);

extern struct filename *getname(const char __user *);

extern struct filename *getname_kernel(const char *);

extern void putname(struct filename *name);



enum {

	FILE_CREATED = 1,
@@ -2182,15 +2184,8 @@ extern void __init vfs_caches_init(unsigned long); 


extern struct kmem_cache *names_cachep;



extern void final_putname(struct filename *name);



#define __getname()		kmem_cache_alloc(names_cachep, GFP_KERNEL)

#define __putname(name)		kmem_cache_free(names_cachep, (void *)(name))

#ifndef CONFIG_AUDITSYSCALL

#define putname(name)		final_putname(name)

#else

extern void putname(struct filename *name);

#endif



#ifdef CONFIG_BLOCK

extern int register_blkdev(unsigned int, const char *);