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-rw-r--r--fs/namei.c294
1 files changed, 182 insertions, 112 deletions
diff --git a/fs/namei.c b/fs/namei.c
index bf6d8a738c59..95a881e0552b 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -204,6 +204,14 @@ getname_flags(const char __user *filename, int flags, int *empty)
}
struct filename *
+getname_uflags(const char __user *filename, int uflags)
+{
+ int flags = (uflags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
+
+ return getname_flags(filename, flags, NULL);
+}
+
+struct filename *
getname(const char __user * filename)
{
return getname_flags(filename, 0, NULL);
@@ -247,6 +255,9 @@ getname_kernel(const char * filename)
void putname(struct filename *name)
{
+ if (IS_ERR_OR_NULL(name))
+ return;
+
BUG_ON(name->refcnt <= 0);
if (--name->refcnt > 0)
@@ -2456,7 +2467,7 @@ static int path_lookupat(struct nameidata *nd, unsigned flags, struct path *path
return err;
}
-int filename_lookup(int dfd, struct filename *name, unsigned flags,
+static int __filename_lookup(int dfd, struct filename *name, unsigned flags,
struct path *path, struct path *root)
{
int retval;
@@ -2474,6 +2485,14 @@ int filename_lookup(int dfd, struct filename *name, unsigned flags,
audit_inode(name, path->dentry,
flags & LOOKUP_MOUNTPOINT ? AUDIT_INODE_NOEVAL : 0);
restore_nameidata();
+ return retval;
+}
+
+int filename_lookup(int dfd, struct filename *name, unsigned flags,
+ struct path *path, struct path *root)
+{
+ int retval = __filename_lookup(dfd, name, flags, path, root);
+
putname(name);
return retval;
}
@@ -2495,7 +2514,7 @@ static int path_parentat(struct nameidata *nd, unsigned flags,
return err;
}
-static struct filename *filename_parentat(int dfd, struct filename *name,
+static int __filename_parentat(int dfd, struct filename *name,
unsigned int flags, struct path *parent,
struct qstr *last, int *type)
{
@@ -2503,7 +2522,7 @@ static struct filename *filename_parentat(int dfd, struct filename *name,
struct nameidata nd;
if (IS_ERR(name))
- return name;
+ return PTR_ERR(name);
set_nameidata(&nd, dfd, name, NULL);
retval = path_parentat(&nd, flags | LOOKUP_RCU, parent);
if (unlikely(retval == -ECHILD))
@@ -2514,29 +2533,34 @@ static struct filename *filename_parentat(int dfd, struct filename *name,
*last = nd.last;
*type = nd.last_type;
audit_inode(name, parent->dentry, AUDIT_INODE_PARENT);
- } else {
- putname(name);
- name = ERR_PTR(retval);
}
restore_nameidata();
- return name;
+ return retval;
+}
+
+static int filename_parentat(int dfd, struct filename *name,
+ unsigned int flags, struct path *parent,
+ struct qstr *last, int *type)
+{
+ int retval = __filename_parentat(dfd, name, flags, parent, last, type);
+
+ putname(name);
+ return retval;
}
/* does lookup, returns the object with parent locked */
struct dentry *kern_path_locked(const char *name, struct path *path)
{
- struct filename *filename;
struct dentry *d;
struct qstr last;
- int type;
+ int type, error;
- filename = filename_parentat(AT_FDCWD, getname_kernel(name), 0, path,
+ error = filename_parentat(AT_FDCWD, getname_kernel(name), 0, path,
&last, &type);
- if (IS_ERR(filename))
- return ERR_CAST(filename);
+ if (error)
+ return ERR_PTR(error);
if (unlikely(type != LAST_NORM)) {
path_put(path);
- putname(filename);
return ERR_PTR(-EINVAL);
}
inode_lock_nested(path->dentry->d_inode, I_MUTEX_PARENT);
@@ -2545,7 +2569,6 @@ struct dentry *kern_path_locked(const char *name, struct path *path)
inode_unlock(path->dentry->d_inode);
path_put(path);
}
- putname(filename);
return d;
}
@@ -2575,8 +2598,9 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
}
EXPORT_SYMBOL(vfs_path_lookup);
-static int lookup_one_len_common(const char *name, struct dentry *base,
- int len, struct qstr *this)
+static int lookup_one_common(struct user_namespace *mnt_userns,
+ const char *name, struct dentry *base, int len,
+ struct qstr *this)
{
this->name = name;
this->len = len;
@@ -2604,7 +2628,7 @@ static int lookup_one_len_common(const char *name, struct dentry *base,
return err;
}
- return inode_permission(&init_user_ns, base->d_inode, MAY_EXEC);
+ return inode_permission(mnt_userns, base->d_inode, MAY_EXEC);
}
/**
@@ -2628,7 +2652,7 @@ struct dentry *try_lookup_one_len(const char *name, struct dentry *base, int len
WARN_ON_ONCE(!inode_is_locked(base->d_inode));
- err = lookup_one_len_common(name, base, len, &this);
+ err = lookup_one_common(&init_user_ns, name, base, len, &this);
if (err)
return ERR_PTR(err);
@@ -2655,7 +2679,7 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
WARN_ON_ONCE(!inode_is_locked(base->d_inode));
- err = lookup_one_len_common(name, base, len, &this);
+ err = lookup_one_common(&init_user_ns, name, base, len, &this);
if (err)
return ERR_PTR(err);
@@ -2665,6 +2689,36 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
EXPORT_SYMBOL(lookup_one_len);
/**
+ * lookup_one - filesystem helper to lookup single pathname component
+ * @mnt_userns: user namespace of the mount the lookup is performed from
+ * @name: pathname component to lookup
+ * @base: base directory to lookup from
+ * @len: maximum length @len should be interpreted to
+ *
+ * Note that this routine is purely a helper for filesystem usage and should
+ * not be called by generic code.
+ *
+ * The caller must hold base->i_mutex.
+ */
+struct dentry *lookup_one(struct user_namespace *mnt_userns, const char *name,
+ struct dentry *base, int len)
+{
+ struct dentry *dentry;
+ struct qstr this;
+ int err;
+
+ WARN_ON_ONCE(!inode_is_locked(base->d_inode));
+
+ err = lookup_one_common(mnt_userns, name, base, len, &this);
+ if (err)
+ return ERR_PTR(err);
+
+ dentry = lookup_dcache(&this, base, 0);
+ return dentry ? dentry : __lookup_slow(&this, base, 0);
+}
+EXPORT_SYMBOL(lookup_one);
+
+/**
* lookup_one_len_unlocked - filesystem helper to lookup single pathname component
* @name: pathname component to lookup
* @base: base directory to lookup from
@@ -2683,7 +2737,7 @@ struct dentry *lookup_one_len_unlocked(const char *name,
int err;
struct dentry *ret;
- err = lookup_one_len_common(name, base, len, &this);
+ err = lookup_one_common(&init_user_ns, name, base, len, &this);
if (err)
return ERR_PTR(err);
@@ -3023,9 +3077,7 @@ static int handle_truncate(struct user_namespace *mnt_userns, struct file *filp)
/*
* Refuse to truncate files with mandatory locks held on them.
*/
- error = locks_verify_locked(filp);
- if (!error)
- error = security_path_truncate(path);
+ error = security_path_truncate(path);
if (!error) {
error = do_truncate(mnt_userns, path->dentry, 0,
ATTR_MTIME|ATTR_CTIME|ATTR_OPEN,
@@ -3566,7 +3618,7 @@ struct file *do_file_open_root(const struct path *root,
return file;
}
-static struct dentry *filename_create(int dfd, struct filename *name,
+static struct dentry *__filename_create(int dfd, struct filename *name,
struct path *path, unsigned int lookup_flags)
{
struct dentry *dentry = ERR_PTR(-EEXIST);
@@ -3582,9 +3634,9 @@ static struct dentry *filename_create(int dfd, struct filename *name,
*/
lookup_flags &= LOOKUP_REVAL;
- name = filename_parentat(dfd, name, lookup_flags, path, &last, &type);
- if (IS_ERR(name))
- return ERR_CAST(name);
+ error = __filename_parentat(dfd, name, lookup_flags, path, &last, &type);
+ if (error)
+ return ERR_PTR(error);
/*
* Yucky last component or no last component at all?
@@ -3622,7 +3674,6 @@ static struct dentry *filename_create(int dfd, struct filename *name,
error = err2;
goto fail;
}
- putname(name);
return dentry;
fail:
dput(dentry);
@@ -3633,10 +3684,18 @@ unlock:
mnt_drop_write(path->mnt);
out:
path_put(path);
- putname(name);
return dentry;
}
+static inline struct dentry *filename_create(int dfd, struct filename *name,
+ struct path *path, unsigned int lookup_flags)
+{
+ struct dentry *res = __filename_create(dfd, name, path, lookup_flags);
+
+ putname(name);
+ return res;
+}
+
struct dentry *kern_path_create(int dfd, const char *pathname,
struct path *path, unsigned int lookup_flags)
{
@@ -3725,7 +3784,7 @@ static int may_mknod(umode_t mode)
}
}
-static long do_mknodat(int dfd, const char __user *filename, umode_t mode,
+static int do_mknodat(int dfd, struct filename *name, umode_t mode,
unsigned int dev)
{
struct user_namespace *mnt_userns;
@@ -3736,17 +3795,18 @@ static long do_mknodat(int dfd, const char __user *filename, umode_t mode,
error = may_mknod(mode);
if (error)
- return error;
+ goto out1;
retry:
- dentry = user_path_create(dfd, filename, &path, lookup_flags);
+ dentry = __filename_create(dfd, name, &path, lookup_flags);
+ error = PTR_ERR(dentry);
if (IS_ERR(dentry))
- return PTR_ERR(dentry);
+ goto out1;
if (!IS_POSIXACL(path.dentry->d_inode))
mode &= ~current_umask();
error = security_path_mknod(&path, dentry, mode, dev);
if (error)
- goto out;
+ goto out2;
mnt_userns = mnt_user_ns(path.mnt);
switch (mode & S_IFMT) {
@@ -3765,24 +3825,26 @@ retry:
dentry, mode, 0);
break;
}
-out:
+out2:
done_path_create(&path, dentry);
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
+out1:
+ putname(name);
return error;
}
SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, umode_t, mode,
unsigned int, dev)
{
- return do_mknodat(dfd, filename, mode, dev);
+ return do_mknodat(dfd, getname(filename), mode, dev);
}
SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, dev)
{
- return do_mknodat(AT_FDCWD, filename, mode, dev);
+ return do_mknodat(AT_FDCWD, getname(filename), mode, dev);
}
/**
@@ -3827,7 +3889,7 @@ int vfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
}
EXPORT_SYMBOL(vfs_mkdir);
-static long do_mkdirat(int dfd, const char __user *pathname, umode_t mode)
+int do_mkdirat(int dfd, struct filename *name, umode_t mode)
{
struct dentry *dentry;
struct path path;
@@ -3835,9 +3897,10 @@ static long do_mkdirat(int dfd, const char __user *pathname, umode_t mode)
unsigned int lookup_flags = LOOKUP_DIRECTORY;
retry:
- dentry = user_path_create(dfd, pathname, &path, lookup_flags);
+ dentry = __filename_create(dfd, name, &path, lookup_flags);
+ error = PTR_ERR(dentry);
if (IS_ERR(dentry))
- return PTR_ERR(dentry);
+ goto out_putname;
if (!IS_POSIXACL(path.dentry->d_inode))
mode &= ~current_umask();
@@ -3853,17 +3916,19 @@ retry:
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
+out_putname:
+ putname(name);
return error;
}
SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, umode_t, mode)
{
- return do_mkdirat(dfd, pathname, mode);
+ return do_mkdirat(dfd, getname(pathname), mode);
}
SYSCALL_DEFINE2(mkdir, const char __user *, pathname, umode_t, mode)
{
- return do_mkdirat(AT_FDCWD, pathname, mode);
+ return do_mkdirat(AT_FDCWD, getname(pathname), mode);
}
/**
@@ -3921,62 +3986,62 @@ out:
}
EXPORT_SYMBOL(vfs_rmdir);
-long do_rmdir(int dfd, struct filename *name)
+int do_rmdir(int dfd, struct filename *name)
{
struct user_namespace *mnt_userns;
- int error = 0;
+ int error;
struct dentry *dentry;
struct path path;
struct qstr last;
int type;
unsigned int lookup_flags = 0;
retry:
- name = filename_parentat(dfd, name, lookup_flags,
- &path, &last, &type);
- if (IS_ERR(name))
- return PTR_ERR(name);
+ error = __filename_parentat(dfd, name, lookup_flags, &path, &last, &type);
+ if (error)
+ goto exit1;
switch (type) {
case LAST_DOTDOT:
error = -ENOTEMPTY;
- goto exit1;
+ goto exit2;
case LAST_DOT:
error = -EINVAL;
- goto exit1;
+ goto exit2;
case LAST_ROOT:
error = -EBUSY;
- goto exit1;
+ goto exit2;
}
error = mnt_want_write(path.mnt);
if (error)
- goto exit1;
+ goto exit2;
inode_lock_nested(path.dentry->d_inode, I_MUTEX_PARENT);
dentry = __lookup_hash(&last, path.dentry, lookup_flags);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
- goto exit2;
+ goto exit3;
if (!dentry->d_inode) {
error = -ENOENT;
- goto exit3;
+ goto exit4;
}
error = security_path_rmdir(&path, dentry);
if (error)
- goto exit3;
+ goto exit4;
mnt_userns = mnt_user_ns(path.mnt);
error = vfs_rmdir(mnt_userns, path.dentry->d_inode, dentry);
-exit3:
+exit4:
dput(dentry);
-exit2:
+exit3:
inode_unlock(path.dentry->d_inode);
mnt_drop_write(path.mnt);
-exit1:
+exit2:
path_put(&path);
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
+exit1:
putname(name);
return error;
}
@@ -4024,7 +4089,9 @@ int vfs_unlink(struct user_namespace *mnt_userns, struct inode *dir,
return -EPERM;
inode_lock(target);
- if (is_local_mountpoint(dentry))
+ if (IS_SWAPFILE(target))
+ error = -EPERM;
+ else if (is_local_mountpoint(dentry))
error = -EBUSY;
else {
error = security_inode_unlink(dir, dentry);
@@ -4059,7 +4126,7 @@ EXPORT_SYMBOL(vfs_unlink);
* writeout happening, and we don't want to prevent access to the directory
* while waiting on the I/O.
*/
-long do_unlinkat(int dfd, struct filename *name)
+int do_unlinkat(int dfd, struct filename *name)
{
int error;
struct dentry *dentry;
@@ -4070,17 +4137,17 @@ long do_unlinkat(int dfd, struct filename *name)
struct inode *delegated_inode = NULL;
unsigned int lookup_flags = 0;
retry:
- name = filename_parentat(dfd, name, lookup_flags, &path, &last, &type);
- if (IS_ERR(name))
- return PTR_ERR(name);
+ error = __filename_parentat(dfd, name, lookup_flags, &path, &last, &type);
+ if (error)
+ goto exit1;
error = -EISDIR;
if (type != LAST_NORM)
- goto exit1;
+ goto exit2;
error = mnt_want_write(path.mnt);
if (error)
- goto exit1;
+ goto exit2;
retry_deleg:
inode_lock_nested(path.dentry->d_inode, I_MUTEX_PARENT);
dentry = __lookup_hash(&last, path.dentry, lookup_flags);
@@ -4097,11 +4164,11 @@ retry_deleg:
ihold(inode);
error = security_path_unlink(&path, dentry);
if (error)
- goto exit2;
+ goto exit3;
mnt_userns = mnt_user_ns(path.mnt);
error = vfs_unlink(mnt_userns, path.dentry->d_inode, dentry,
&delegated_inode);
-exit2:
+exit3:
dput(dentry);
}
inode_unlock(path.dentry->d_inode);
@@ -4114,13 +4181,14 @@ exit2:
goto retry_deleg;
}
mnt_drop_write(path.mnt);
-exit1:
+exit2:
path_put(&path);
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
inode = NULL;
goto retry;
}
+exit1:
putname(name);
return error;
@@ -4131,7 +4199,7 @@ slashes:
error = -EISDIR;
else
error = -ENOTDIR;
- goto exit2;
+ goto exit3;
}
SYSCALL_DEFINE3(unlinkat, int, dfd, const char __user *, pathname, int, flag)
@@ -4186,23 +4254,22 @@ int vfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
}
EXPORT_SYMBOL(vfs_symlink);
-static long do_symlinkat(const char __user *oldname, int newdfd,
- const char __user *newname)
+int do_symlinkat(struct filename *from, int newdfd, struct filename *to)
{
int error;
- struct filename *from;
struct dentry *dentry;
struct path path;
unsigned int lookup_flags = 0;
- from = getname(oldname);
- if (IS_ERR(from))
- return PTR_ERR(from);
+ if (IS_ERR(from)) {
+ error = PTR_ERR(from);
+ goto out_putnames;
+ }
retry:
- dentry = user_path_create(newdfd, newname, &path, lookup_flags);
+ dentry = __filename_create(newdfd, to, &path, lookup_flags);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
- goto out_putname;
+ goto out_putnames;
error = security_path_symlink(&path, dentry, from->name);
if (!error) {
@@ -4217,7 +4284,8 @@ retry:
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
-out_putname:
+out_putnames:
+ putname(to);
putname(from);
return error;
}
@@ -4225,12 +4293,12 @@ out_putname:
SYSCALL_DEFINE3(symlinkat, const char __user *, oldname,
int, newdfd, const char __user *, newname)
{
- return do_symlinkat(oldname, newdfd, newname);
+ return do_symlinkat(getname(oldname), newdfd, getname(newname));
}
SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newname)
{
- return do_symlinkat(oldname, AT_FDCWD, newname);
+ return do_symlinkat(getname(oldname), AT_FDCWD, getname(newname));
}
/**
@@ -4331,8 +4399,8 @@ EXPORT_SYMBOL(vfs_link);
* with linux 2.0, and to avoid hard-linking to directories
* and other special files. --ADM
*/
-static int do_linkat(int olddfd, const char __user *oldname, int newdfd,
- const char __user *newname, int flags)
+int do_linkat(int olddfd, struct filename *old, int newdfd,
+ struct filename *new, int flags)
{
struct user_namespace *mnt_userns;
struct dentry *new_dentry;
@@ -4341,31 +4409,32 @@ static int do_linkat(int olddfd, const char __user *oldname, int newdfd,
int how = 0;
int error;
- if ((flags & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH)) != 0)
- return -EINVAL;
+ if ((flags & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH)) != 0) {
+ error = -EINVAL;
+ goto out_putnames;
+ }
/*
* To use null names we require CAP_DAC_READ_SEARCH
* This ensures that not everyone will be able to create
* handlink using the passed filedescriptor.
*/
- if (flags & AT_EMPTY_PATH) {
- if (!capable(CAP_DAC_READ_SEARCH))
- return -ENOENT;
- how = LOOKUP_EMPTY;
+ if (flags & AT_EMPTY_PATH && !capable(CAP_DAC_READ_SEARCH)) {
+ error = -ENOENT;
+ goto out_putnames;
}
if (flags & AT_SYMLINK_FOLLOW)
how |= LOOKUP_FOLLOW;
retry:
- error = user_path_at(olddfd, oldname, how, &old_path);
+ error = __filename_lookup(olddfd, old, how, &old_path, NULL);
if (error)
- return error;
+ goto out_putnames;
- new_dentry = user_path_create(newdfd, newname, &new_path,
+ new_dentry = __filename_create(newdfd, new, &new_path,
(how & LOOKUP_REVAL));
error = PTR_ERR(new_dentry);
if (IS_ERR(new_dentry))
- goto out;
+ goto out_putpath;
error = -EXDEV;
if (old_path.mnt != new_path.mnt)
@@ -4393,8 +4462,11 @@ out_dput:
how |= LOOKUP_REVAL;
goto retry;
}
-out:
+out_putpath:
path_put(&old_path);
+out_putnames:
+ putname(old);
+ putname(new);
return error;
}
@@ -4402,12 +4474,13 @@ out:
SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname,
int, newdfd, const char __user *, newname, int, flags)
{
- return do_linkat(olddfd, oldname, newdfd, newname, flags);
+ return do_linkat(olddfd, getname_uflags(oldname, flags),
+ newdfd, getname(newname), flags);
}
SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname)
{
- return do_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
+ return do_linkat(AT_FDCWD, getname(oldname), AT_FDCWD, getname(newname), 0);
}
/**
@@ -4526,6 +4599,10 @@ int vfs_rename(struct renamedata *rd)
else if (target)
inode_lock(target);
+ error = -EPERM;
+ if (IS_SWAPFILE(source) || (target && IS_SWAPFILE(target)))
+ goto out;
+
error = -EBUSY;
if (is_local_mountpoint(old_dentry) || is_local_mountpoint(new_dentry))
goto out;
@@ -4602,29 +4679,25 @@ int do_renameat2(int olddfd, struct filename *from, int newdfd,
int error = -EINVAL;
if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
- goto put_both;
+ goto put_names;
if ((flags & (RENAME_NOREPLACE | RENAME_WHITEOUT)) &&
(flags & RENAME_EXCHANGE))
- goto put_both;
+ goto put_names;
if (flags & RENAME_EXCHANGE)
target_flags = 0;
retry:
- from = filename_parentat(olddfd, from, lookup_flags, &old_path,
+ error = __filename_parentat(olddfd, from, lookup_flags, &old_path,
&old_last, &old_type);
- if (IS_ERR(from)) {
- error = PTR_ERR(from);
- goto put_new;
- }
+ if (error)
+ goto put_names;
- to = filename_parentat(newdfd, to, lookup_flags, &new_path, &new_last,
+ error = __filename_parentat(newdfd, to, lookup_flags, &new_path, &new_last,
&new_type);
- if (IS_ERR(to)) {
- error = PTR_ERR(to);
+ if (error)
goto exit1;
- }
error = -EXDEV;
if (old_path.mnt != new_path.mnt)
@@ -4727,12 +4800,9 @@ exit1:
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
-put_both:
- if (!IS_ERR(from))
- putname(from);
-put_new:
- if (!IS_ERR(to))
- putname(to);
+put_names:
+ putname(from);
+ putname(to);
return error;
}