*/
#include <linux/fs.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
#include <linux/file.h>
#include <linux/xattr.h>
+#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/security.h>
+#include <linux/evm.h>
#include <linux/syscalls.h>
-#include <linux/module.h>
+#include <linux/export.h>
#include <linux/fsnotify.h>
#include <linux/audit.h>
-#include <asm/uaccess.h>
+#include <linux/vmalloc.h>
+#include <asm/uaccess.h>
/*
* Check permissions for extended attribute access. This is a bit complicated
* filesystem or on an immutable / append-only inode.
*/
if (mask & MAY_WRITE) {
- if (IS_RDONLY(inode))
- return -EROFS;
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
return -EPERM;
}
return 0;
/*
- * The trusted.* namespace can only accessed by a privilegued user.
+ * The trusted.* namespace can only be accessed by privileged users.
*/
- if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
- return (capable(CAP_SYS_ADMIN) ? 0 : -EPERM);
+ if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN)) {
+ if (!capable(CAP_SYS_ADMIN))
+ return (mask & MAY_WRITE) ? -EPERM : -ENODATA;
+ return 0;
+ }
+ /*
+ * In the user.* namespace, only regular files and directories can have
+ * extended attributes. For sticky directories, only the owner and
+ * privileged users can write attributes.
+ */
if (!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) {
- if (!S_ISREG(inode->i_mode) &&
- (!S_ISDIR(inode->i_mode) || inode->i_mode & S_ISVTX))
+ if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
+ return (mask & MAY_WRITE) ? -EPERM : -ENODATA;
+ if (S_ISDIR(inode->i_mode) && (inode->i_mode & S_ISVTX) &&
+ (mask & MAY_WRITE) && !inode_owner_or_capable(inode))
return -EPERM;
}
- return permission(inode, mask, NULL);
+ return inode_permission(inode, mask);
}
-int
-vfs_setxattr(struct dentry *dentry, char *name, void *value,
- size_t size, int flags)
+/**
+ * __vfs_setxattr_noperm - perform setxattr operation without performing
+ * permission checks.
+ *
+ * @dentry - object to perform setxattr on
+ * @name - xattr name to set
+ * @value - value to set @name to
+ * @size - size of @value
+ * @flags - flags to pass into filesystem operations
+ *
+ * returns the result of the internal setxattr or setsecurity operations.
+ *
+ * This function requires the caller to lock the inode's i_mutex before it
+ * is executed. It also assumes that the caller will make the appropriate
+ * permission checks.
+ */
+int __vfs_setxattr_noperm(struct dentry *dentry, const char *name,
+ const void *value, size_t size, int flags)
{
struct inode *inode = dentry->d_inode;
- int error;
+ int error = -EOPNOTSUPP;
+ int issec = !strncmp(name, XATTR_SECURITY_PREFIX,
+ XATTR_SECURITY_PREFIX_LEN);
- error = xattr_permission(inode, name, MAY_WRITE);
- if (error)
- return error;
-
- mutex_lock(&inode->i_mutex);
- error = security_inode_setxattr(dentry, name, value, size, flags);
- if (error)
- goto out;
- error = -EOPNOTSUPP;
+ if (issec)
+ inode->i_flags &= ~S_NOSEC;
if (inode->i_op->setxattr) {
error = inode->i_op->setxattr(dentry, name, value, size, flags);
if (!error) {
security_inode_post_setxattr(dentry, name, value,
size, flags);
}
- } else if (!strncmp(name, XATTR_SECURITY_PREFIX,
- XATTR_SECURITY_PREFIX_LEN)) {
+ } else if (issec) {
const char *suffix = name + XATTR_SECURITY_PREFIX_LEN;
error = security_inode_setsecurity(inode, suffix, value,
size, flags);
if (!error)
fsnotify_xattr(dentry);
}
+
+ return error;
+}
+
+
+int
+vfs_setxattr(struct dentry *dentry, const char *name, const void *value,
+ size_t size, int flags)
+{
+ struct inode *inode = dentry->d_inode;
+ int error;
+
+ error = xattr_permission(inode, name, MAY_WRITE);
+ if (error)
+ return error;
+
+ mutex_lock(&inode->i_mutex);
+ error = security_inode_setxattr(dentry, name, value, size, flags);
+ if (error)
+ goto out;
+
+ error = __vfs_setxattr_noperm(dentry, name, value, size, flags);
+
out:
mutex_unlock(&inode->i_mutex);
return error;
EXPORT_SYMBOL_GPL(vfs_setxattr);
ssize_t
-vfs_getxattr(struct dentry *dentry, char *name, void *value, size_t size)
+xattr_getsecurity(struct inode *inode, const char *name, void *value,
+ size_t size)
+{
+ void *buffer = NULL;
+ ssize_t len;
+
+ if (!value || !size) {
+ len = security_inode_getsecurity(inode, name, &buffer, false);
+ goto out_noalloc;
+ }
+
+ len = security_inode_getsecurity(inode, name, &buffer, true);
+ if (len < 0)
+ return len;
+ if (size < len) {
+ len = -ERANGE;
+ goto out;
+ }
+ memcpy(value, buffer, len);
+out:
+ security_release_secctx(buffer, len);
+out_noalloc:
+ return len;
+}
+EXPORT_SYMBOL_GPL(xattr_getsecurity);
+
+/*
+ * vfs_getxattr_alloc - allocate memory, if necessary, before calling getxattr
+ *
+ * Allocate memory, if not already allocated, or re-allocate correct size,
+ * before retrieving the extended attribute.
+ *
+ * Returns the result of alloc, if failed, or the getxattr operation.
+ */
+ssize_t
+vfs_getxattr_alloc(struct dentry *dentry, const char *name, char **xattr_value,
+ size_t xattr_size, gfp_t flags)
{
struct inode *inode = dentry->d_inode;
+ char *value = *xattr_value;
int error;
error = xattr_permission(inode, name, MAY_READ);
if (error)
return error;
- error = security_inode_getxattr(dentry, name);
- if (error)
+ if (!inode->i_op->getxattr)
+ return -EOPNOTSUPP;
+
+ error = inode->i_op->getxattr(dentry, name, NULL, 0);
+ if (error < 0)
return error;
- if (inode->i_op->getxattr)
- error = inode->i_op->getxattr(dentry, name, value, size);
+ if (!value || (error > xattr_size)) {
+ value = krealloc(*xattr_value, error + 1, flags);
+ if (!value)
+ return -ENOMEM;
+ memset(value, 0, error + 1);
+ }
+
+ error = inode->i_op->getxattr(dentry, name, value, error);
+ *xattr_value = value;
+ return error;
+}
+
+/* Compare an extended attribute value with the given value */
+int vfs_xattr_cmp(struct dentry *dentry, const char *xattr_name,
+ const char *value, size_t size, gfp_t flags)
+{
+ char *xattr_value = NULL;
+ int rc;
+
+ rc = vfs_getxattr_alloc(dentry, xattr_name, &xattr_value, 0, flags);
+ if (rc < 0)
+ return rc;
+
+ if ((rc != size) || (memcmp(xattr_value, value, rc) != 0))
+ rc = -EINVAL;
else
- error = -EOPNOTSUPP;
+ rc = 0;
+ kfree(xattr_value);
+ return rc;
+}
+
+ssize_t
+vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size)
+{
+ struct inode *inode = dentry->d_inode;
+ int error;
+
+ error = xattr_permission(inode, name, MAY_READ);
+ if (error)
+ return error;
+
+ error = security_inode_getxattr(dentry, name);
+ if (error)
+ return error;
if (!strncmp(name, XATTR_SECURITY_PREFIX,
XATTR_SECURITY_PREFIX_LEN)) {
const char *suffix = name + XATTR_SECURITY_PREFIX_LEN;
- int ret = security_inode_getsecurity(inode, suffix, value,
- size, error);
+ int ret = xattr_getsecurity(inode, suffix, value, size);
/*
* Only overwrite the return value if a security module
* is actually active.
*/
- if (ret != -EOPNOTSUPP)
- error = ret;
+ if (ret == -EOPNOTSUPP)
+ goto nolsm;
+ return ret;
}
+nolsm:
+ if (inode->i_op->getxattr)
+ error = inode->i_op->getxattr(dentry, name, value, size);
+ else
+ error = -EOPNOTSUPP;
return error;
}
EXPORT_SYMBOL_GPL(vfs_getxattr);
+ssize_t
+vfs_listxattr(struct dentry *d, char *list, size_t size)
+{
+ ssize_t error;
+
+ error = security_inode_listxattr(d);
+ if (error)
+ return error;
+ error = -EOPNOTSUPP;
+ if (d->d_inode->i_op->listxattr) {
+ error = d->d_inode->i_op->listxattr(d, list, size);
+ } else {
+ error = security_inode_listsecurity(d->d_inode, list, size);
+ if (size && error > size)
+ error = -ERANGE;
+ }
+ return error;
+}
+EXPORT_SYMBOL_GPL(vfs_listxattr);
+
int
-vfs_removexattr(struct dentry *dentry, char *name)
+vfs_removexattr(struct dentry *dentry, const char *name)
{
struct inode *inode = dentry->d_inode;
int error;
error = inode->i_op->removexattr(dentry, name);
mutex_unlock(&inode->i_mutex);
- if (!error)
+ if (!error) {
fsnotify_xattr(dentry);
+ evm_inode_post_removexattr(dentry, name);
+ }
return error;
}
EXPORT_SYMBOL_GPL(vfs_removexattr);
* Extended attribute SET operations
*/
static long
-setxattr(struct dentry *d, char __user *name, void __user *value,
+setxattr(struct dentry *d, const char __user *name, const void __user *value,
size_t size, int flags)
{
int error;
void *kvalue = NULL;
+ void *vvalue = NULL; /* If non-NULL, we used vmalloc() */
char kname[XATTR_NAME_MAX + 1];
if (flags & ~(XATTR_CREATE|XATTR_REPLACE))
if (size) {
if (size > XATTR_SIZE_MAX)
return -E2BIG;
- kvalue = kmalloc(size, GFP_KERNEL);
- if (!kvalue)
- return -ENOMEM;
+ kvalue = kmalloc(size, GFP_KERNEL | __GFP_NOWARN);
+ if (!kvalue) {
+ vvalue = vmalloc(size);
+ if (!vvalue)
+ return -ENOMEM;
+ kvalue = vvalue;
+ }
if (copy_from_user(kvalue, value, size)) {
- kfree(kvalue);
- return -EFAULT;
+ error = -EFAULT;
+ goto out;
}
}
error = vfs_setxattr(d, kname, kvalue, size, flags);
- kfree(kvalue);
+out:
+ if (vvalue)
+ vfree(vvalue);
+ else
+ kfree(kvalue);
return error;
}
-asmlinkage long
-sys_setxattr(char __user *path, char __user *name, void __user *value,
- size_t size, int flags)
+SYSCALL_DEFINE5(setxattr, const char __user *, pathname,
+ const char __user *, name, const void __user *, value,
+ size_t, size, int, flags)
{
- struct nameidata nd;
+ struct path path;
int error;
- error = user_path_walk(path, &nd);
+ error = user_path(pathname, &path);
if (error)
return error;
- error = setxattr(nd.dentry, name, value, size, flags);
- path_release(&nd);
+ error = mnt_want_write(path.mnt);
+ if (!error) {
+ error = setxattr(path.dentry, name, value, size, flags);
+ mnt_drop_write(path.mnt);
+ }
+ path_put(&path);
return error;
}
-asmlinkage long
-sys_lsetxattr(char __user *path, char __user *name, void __user *value,
- size_t size, int flags)
+SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname,
+ const char __user *, name, const void __user *, value,
+ size_t, size, int, flags)
{
- struct nameidata nd;
+ struct path path;
int error;
- error = user_path_walk_link(path, &nd);
+ error = user_lpath(pathname, &path);
if (error)
return error;
- error = setxattr(nd.dentry, name, value, size, flags);
- path_release(&nd);
+ error = mnt_want_write(path.mnt);
+ if (!error) {
+ error = setxattr(path.dentry, name, value, size, flags);
+ mnt_drop_write(path.mnt);
+ }
+ path_put(&path);
return error;
}
-asmlinkage long
-sys_fsetxattr(int fd, char __user *name, void __user *value,
- size_t size, int flags)
+SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name,
+ const void __user *,value, size_t, size, int, flags)
{
struct file *f;
struct dentry *dentry;
f = fget(fd);
if (!f)
return error;
- dentry = f->f_dentry;
- audit_inode(NULL, dentry->d_inode, 0);
- error = setxattr(dentry, name, value, size, flags);
+ dentry = f->f_path.dentry;
+ audit_inode(NULL, dentry);
+ error = mnt_want_write_file(f);
+ if (!error) {
+ error = setxattr(dentry, name, value, size, flags);
+ mnt_drop_write_file(f);
+ }
fput(f);
return error;
}
* Extended attribute GET operations
*/
static ssize_t
-getxattr(struct dentry *d, char __user *name, void __user *value, size_t size)
+getxattr(struct dentry *d, const char __user *name, void __user *value,
+ size_t size)
{
ssize_t error;
void *kvalue = NULL;
return error;
}
-asmlinkage ssize_t
-sys_getxattr(char __user *path, char __user *name, void __user *value,
- size_t size)
+SYSCALL_DEFINE4(getxattr, const char __user *, pathname,
+ const char __user *, name, void __user *, value, size_t, size)
{
- struct nameidata nd;
+ struct path path;
ssize_t error;
- error = user_path_walk(path, &nd);
+ error = user_path(pathname, &path);
if (error)
return error;
- error = getxattr(nd.dentry, name, value, size);
- path_release(&nd);
+ error = getxattr(path.dentry, name, value, size);
+ path_put(&path);
return error;
}
-asmlinkage ssize_t
-sys_lgetxattr(char __user *path, char __user *name, void __user *value,
- size_t size)
+SYSCALL_DEFINE4(lgetxattr, const char __user *, pathname,
+ const char __user *, name, void __user *, value, size_t, size)
{
- struct nameidata nd;
+ struct path path;
ssize_t error;
- error = user_path_walk_link(path, &nd);
+ error = user_lpath(pathname, &path);
if (error)
return error;
- error = getxattr(nd.dentry, name, value, size);
- path_release(&nd);
+ error = getxattr(path.dentry, name, value, size);
+ path_put(&path);
return error;
}
-asmlinkage ssize_t
-sys_fgetxattr(int fd, char __user *name, void __user *value, size_t size)
+SYSCALL_DEFINE4(fgetxattr, int, fd, const char __user *, name,
+ void __user *, value, size_t, size)
{
struct file *f;
ssize_t error = -EBADF;
f = fget(fd);
if (!f)
return error;
- error = getxattr(f->f_dentry, name, value, size);
+ audit_inode(NULL, f->f_path.dentry);
+ error = getxattr(f->f_path.dentry, name, value, size);
fput(f);
return error;
}
{
ssize_t error;
char *klist = NULL;
+ char *vlist = NULL; /* If non-NULL, we used vmalloc() */
if (size) {
if (size > XATTR_LIST_MAX)
size = XATTR_LIST_MAX;
- klist = kmalloc(size, GFP_KERNEL);
- if (!klist)
- return -ENOMEM;
+ klist = kmalloc(size, __GFP_NOWARN | GFP_KERNEL);
+ if (!klist) {
+ vlist = vmalloc(size);
+ if (!vlist)
+ return -ENOMEM;
+ klist = vlist;
+ }
}
- error = security_inode_listxattr(d);
- if (error)
- goto out;
- error = -EOPNOTSUPP;
- if (d->d_inode->i_op && d->d_inode->i_op->listxattr) {
- error = d->d_inode->i_op->listxattr(d, klist, size);
- } else {
- error = security_inode_listsecurity(d->d_inode, klist, size);
- if (size && error > size)
- error = -ERANGE;
- }
+ error = vfs_listxattr(d, klist, size);
if (error > 0) {
if (size && copy_to_user(list, klist, error))
error = -EFAULT;
than XATTR_LIST_MAX bytes. Not possible. */
error = -E2BIG;
}
-out:
- kfree(klist);
+ if (vlist)
+ vfree(vlist);
+ else
+ kfree(klist);
return error;
}
-asmlinkage ssize_t
-sys_listxattr(char __user *path, char __user *list, size_t size)
+SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list,
+ size_t, size)
{
- struct nameidata nd;
+ struct path path;
ssize_t error;
- error = user_path_walk(path, &nd);
+ error = user_path(pathname, &path);
if (error)
return error;
- error = listxattr(nd.dentry, list, size);
- path_release(&nd);
+ error = listxattr(path.dentry, list, size);
+ path_put(&path);
return error;
}
-asmlinkage ssize_t
-sys_llistxattr(char __user *path, char __user *list, size_t size)
+SYSCALL_DEFINE3(llistxattr, const char __user *, pathname, char __user *, list,
+ size_t, size)
{
- struct nameidata nd;
+ struct path path;
ssize_t error;
- error = user_path_walk_link(path, &nd);
+ error = user_lpath(pathname, &path);
if (error)
return error;
- error = listxattr(nd.dentry, list, size);
- path_release(&nd);
+ error = listxattr(path.dentry, list, size);
+ path_put(&path);
return error;
}
-asmlinkage ssize_t
-sys_flistxattr(int fd, char __user *list, size_t size)
+SYSCALL_DEFINE3(flistxattr, int, fd, char __user *, list, size_t, size)
{
struct file *f;
ssize_t error = -EBADF;
f = fget(fd);
if (!f)
return error;
- error = listxattr(f->f_dentry, list, size);
+ audit_inode(NULL, f->f_path.dentry);
+ error = listxattr(f->f_path.dentry, list, size);
fput(f);
return error;
}
* Extended attribute REMOVE operations
*/
static long
-removexattr(struct dentry *d, char __user *name)
+removexattr(struct dentry *d, const char __user *name)
{
int error;
char kname[XATTR_NAME_MAX + 1];
return vfs_removexattr(d, kname);
}
-asmlinkage long
-sys_removexattr(char __user *path, char __user *name)
+SYSCALL_DEFINE2(removexattr, const char __user *, pathname,
+ const char __user *, name)
{
- struct nameidata nd;
+ struct path path;
int error;
- error = user_path_walk(path, &nd);
+ error = user_path(pathname, &path);
if (error)
return error;
- error = removexattr(nd.dentry, name);
- path_release(&nd);
+ error = mnt_want_write(path.mnt);
+ if (!error) {
+ error = removexattr(path.dentry, name);
+ mnt_drop_write(path.mnt);
+ }
+ path_put(&path);
return error;
}
-asmlinkage long
-sys_lremovexattr(char __user *path, char __user *name)
+SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname,
+ const char __user *, name)
{
- struct nameidata nd;
+ struct path path;
int error;
- error = user_path_walk_link(path, &nd);
+ error = user_lpath(pathname, &path);
if (error)
return error;
- error = removexattr(nd.dentry, name);
- path_release(&nd);
+ error = mnt_want_write(path.mnt);
+ if (!error) {
+ error = removexattr(path.dentry, name);
+ mnt_drop_write(path.mnt);
+ }
+ path_put(&path);
return error;
}
-asmlinkage long
-sys_fremovexattr(int fd, char __user *name)
+SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name)
{
struct file *f;
struct dentry *dentry;
f = fget(fd);
if (!f)
return error;
- dentry = f->f_dentry;
- audit_inode(NULL, dentry->d_inode, 0);
- error = removexattr(dentry, name);
+ dentry = f->f_path.dentry;
+ audit_inode(NULL, dentry);
+ error = mnt_want_write_file(f);
+ if (!error) {
+ error = removexattr(dentry, name);
+ mnt_drop_write_file(f);
+ }
fput(f);
return error;
}
/*
* Find the xattr_handler with the matching prefix.
*/
-static struct xattr_handler *
-xattr_resolve_name(struct xattr_handler **handlers, const char **name)
+static const struct xattr_handler *
+xattr_resolve_name(const struct xattr_handler **handlers, const char **name)
{
- struct xattr_handler *handler;
+ const struct xattr_handler *handler;
if (!*name)
return NULL;
ssize_t
generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t size)
{
- struct xattr_handler *handler;
- struct inode *inode = dentry->d_inode;
+ const struct xattr_handler *handler;
- handler = xattr_resolve_name(inode->i_sb->s_xattr, &name);
+ handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
if (!handler)
return -EOPNOTSUPP;
- return handler->get(inode, name, buffer, size);
+ return handler->get(dentry, name, buffer, size, handler->flags);
}
/*
ssize_t
generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
{
- struct inode *inode = dentry->d_inode;
- struct xattr_handler *handler, **handlers = inode->i_sb->s_xattr;
+ const struct xattr_handler *handler, **handlers = dentry->d_sb->s_xattr;
unsigned int size = 0;
if (!buffer) {
- for_each_xattr_handler(handlers, handler)
- size += handler->list(inode, NULL, 0, NULL, 0);
+ for_each_xattr_handler(handlers, handler) {
+ size += handler->list(dentry, NULL, 0, NULL, 0,
+ handler->flags);
+ }
} else {
char *buf = buffer;
for_each_xattr_handler(handlers, handler) {
- size = handler->list(inode, buf, buffer_size, NULL, 0);
+ size = handler->list(dentry, buf, buffer_size,
+ NULL, 0, handler->flags);
if (size > buffer_size)
return -ERANGE;
buf += size;
int
generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags)
{
- struct xattr_handler *handler;
- struct inode *inode = dentry->d_inode;
+ const struct xattr_handler *handler;
if (size == 0)
value = ""; /* empty EA, do not remove */
- handler = xattr_resolve_name(inode->i_sb->s_xattr, &name);
+ handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
if (!handler)
return -EOPNOTSUPP;
- return handler->set(inode, name, value, size, flags);
+ return handler->set(dentry, name, value, size, flags, handler->flags);
}
/*
int
generic_removexattr(struct dentry *dentry, const char *name)
{
- struct xattr_handler *handler;
- struct inode *inode = dentry->d_inode;
+ const struct xattr_handler *handler;
- handler = xattr_resolve_name(inode->i_sb->s_xattr, &name);
+ handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
if (!handler)
return -EOPNOTSUPP;
- return handler->set(inode, name, NULL, 0, XATTR_REPLACE);
+ return handler->set(dentry, name, NULL, 0,
+ XATTR_REPLACE, handler->flags);
}
EXPORT_SYMBOL(generic_getxattr);
projects / linux-flexiantxendom0-3.2.10.git / blobdiff