#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
return 0;
/*
- * The trusted.* namespace can only be accessed by a privileged 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 user.* namespace, only regular files and directories can have
+ /*
+ * In the user.* namespace, only regular files and directories can have
* extended attributes. For sticky directories, only the owner and
- * privileged user can write attributes.
+ * 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))
- return -EPERM;
+ return (mask & MAY_WRITE) ? -EPERM : -ENODATA;
if (S_ISDIR(inode->i_mode) && (inode->i_mode & S_ISVTX) &&
- (mask & MAY_WRITE) && !is_owner_or_cap(inode))
+ (mask & MAY_WRITE) && !inode_owner_or_capable(inode))
return -EPERM;
}
{
struct inode *inode = dentry->d_inode;
int error = -EOPNOTSUPP;
+ int issec = !strncmp(name, XATTR_SECURITY_PREFIX,
+ XATTR_SECURITY_PREFIX_LEN);
+ 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);
}
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;
+
+ if (!inode->i_op->getxattr)
+ return -EOPNOTSUPP;
+
+ error = inode->i_op->getxattr(dentry, name, NULL, 0);
+ if (error < 0)
+ return error;
+
+ 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
+ rc = 0;
+ kfree(xattr_value);
+ return rc;
+}
+
ssize_t
vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size)
{
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);
{
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 = memdup_user(value, size);
- if (IS_ERR(kvalue))
- return PTR_ERR(kvalue);
+ 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)) {
+ error = -EFAULT;
+ goto out;
+ }
}
error = vfs_setxattr(d, kname, kvalue, size, flags);
- kfree(kvalue);
+out:
+ if (vvalue)
+ vfree(vvalue);
+ else
+ kfree(kvalue);
return error;
}
error = mnt_want_write_file(f);
if (!error) {
error = setxattr(dentry, name, value, size, flags);
- mnt_drop_write(f->f_path.mnt);
+ mnt_drop_write_file(f);
}
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 = vfs_listxattr(d, klist, size);
than XATTR_LIST_MAX bytes. Not possible. */
error = -E2BIG;
}
- kfree(klist);
+ if (vlist)
+ vfree(vlist);
+ else
+ kfree(klist);
return error;
}
error = mnt_want_write_file(f);
if (!error) {
error = removexattr(dentry, name);
- mnt_drop_write(f->f_path.mnt);
+ 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