}
for (name = buf; name < (buf + list_size); name += strlen(name) + 1) {
+ if (ovl_is_private_xattr(name))
+ continue;
retry:
size = vfs_getxattr(old, name, value, value_size);
if (size == -ERANGE)
goto retry;
}
+ error = security_inode_copy_up_xattr(name);
+ if (error < 0 && error != -EOPNOTSUPP)
+ break;
+ if (error == 1) {
+ error = 0;
+ continue; /* Discard */
+ }
error = vfs_setxattr(new, name, value, size, 0);
if (error)
break;
struct dentry *upper = NULL;
umode_t mode = stat->mode;
int err;
+ const struct cred *old_creds = NULL;
+ struct cred *new_creds = NULL;
newdentry = ovl_lookup_temp(workdir, dentry);
err = PTR_ERR(newdentry);
if (IS_ERR(upper))
goto out1;
+ err = security_inode_copy_up(dentry, &new_creds);
+ if (err < 0)
+ goto out2;
+
+ if (new_creds)
+ old_creds = override_creds(new_creds);
+
/* Can't properly set mode on creation because of the umask */
stat->mode &= S_IFMT;
err = ovl_create_real(wdir, newdentry, stat, link, NULL, true);
stat->mode = mode;
+
+ if (new_creds) {
+ revert_creds(old_creds);
+ put_cred(new_creds);
+ }
+
if (err)
goto out2;
#include <linux/xattr.h>
#include <linux/security.h>
#include <linux/cred.h>
+#include <linux/posix_acl.h>
+#include <linux/posix_acl_xattr.h>
#include "overlayfs.h"
void ovl_cleanup(struct inode *wdir, struct dentry *wdentry)
struct dentry *newdentry;
int err;
+ if (!hardlink && !IS_POSIXACL(udir))
+ stat->mode &= ~current_umask();
+
inode_lock_nested(udir, I_MUTEX_PARENT);
newdentry = lookup_one_len(dentry->d_name.name, upperdir,
dentry->d_name.len);
return ret;
}
+static int ovl_set_upper_acl(struct dentry *upperdentry, const char *name,
+ const struct posix_acl *acl)
+{
+ void *buffer;
+ size_t size;
+ int err;
+
+ if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !acl)
+ return 0;
+
+ size = posix_acl_to_xattr(NULL, acl, NULL, 0);
+ buffer = kmalloc(size, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+
+ size = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
+ err = size;
+ if (err < 0)
+ goto out_free;
+
+ err = vfs_setxattr(upperdentry, name, buffer, size, XATTR_CREATE);
+out_free:
+ kfree(buffer);
+ return err;
+}
+
static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
struct kstat *stat, const char *link,
struct dentry *hardlink)
struct dentry *upper;
struct dentry *newdentry;
int err;
+ struct posix_acl *acl, *default_acl;
if (WARN_ON(!workdir))
return -EROFS;
+ if (!hardlink) {
+ err = posix_acl_create(dentry->d_parent->d_inode,
+ &stat->mode, &default_acl, &acl);
+ if (err)
+ return err;
+ }
+
err = ovl_lock_rename_workdir(workdir, upperdir);
if (err)
goto out;
if (err)
goto out_cleanup;
}
+ if (!hardlink) {
+ err = ovl_set_upper_acl(newdentry, XATTR_NAME_POSIX_ACL_ACCESS,
+ acl);
+ if (err)
+ goto out_cleanup;
+
+ err = ovl_set_upper_acl(newdentry, XATTR_NAME_POSIX_ACL_DEFAULT,
+ default_acl);
+ if (err)
+ goto out_cleanup;
+ }
if (!hardlink && S_ISDIR(stat->mode)) {
err = ovl_set_opaque(newdentry);
out_unlock:
unlock_rename(workdir, upperdir);
out:
+ if (!hardlink) {
+ posix_acl_release(acl);
+ posix_acl_release(default_acl);
+ }
return err;
out_cleanup:
if (override_cred) {
override_cred->fsuid = inode->i_uid;
override_cred->fsgid = inode->i_gid;
+ if (!hardlink) {
+ err = security_dentry_create_files_as(dentry,
+ stat->mode, &dentry->d_name, old_cred,
+ override_cred);
+ if (err) {
+ put_cred(override_cred);
+ goto out_revert_creds;
+ }
+ }
put_cred(override_creds(override_cred));
put_cred(override_cred);
err = ovl_create_over_whiteout(dentry, inode, stat,
link, hardlink);
}
+ out_revert_creds:
revert_creds(old_cred);
if (!err) {
struct inode *realinode = d_inode(ovl_dentry_upper(dentry));
.symlink = ovl_symlink,
.unlink = ovl_unlink,
.rmdir = ovl_rmdir,
- .rename2 = ovl_rename2,
+ .rename = ovl_rename2,
.link = ovl_link,
.setattr = ovl_setattr,
.create = ovl_create,
.permission = ovl_permission,
.getattr = ovl_dir_getattr,
.setxattr = generic_setxattr,
- .getxattr = ovl_getxattr,
+ .getxattr = generic_getxattr,
.listxattr = ovl_listxattr,
- .removexattr = ovl_removexattr,
+ .removexattr = generic_removexattr,
.get_acl = ovl_get_acl,
.update_time = ovl_update_time,
};
* @name name of the last path component used to create file
* @ctx pointer to place the pointer to the resulting context in.
* @ctxlen point to place the length of the resulting context.
+ * @dentry_create_files_as:
+ * Compute a context for a dentry as the inode is not yet available
+ * and set that context in passed in creds so that new files are
+ * created using that context. Context is calculated using the
+ * passed in creds and not the creds of the caller.
+ * @dentry dentry to use in calculating the context.
+ * @mode mode used to determine resource type.
+ * @name name of the last path component used to create file
+ * @old creds which should be used for context calculation
+ * @new creds to modify
*
*
* Security hooks for inode operations.
* @inode contains a pointer to the inode.
* @secid contains a pointer to the location where result will be saved.
* In case of failure, @secid will be set to zero.
+ * @inode_copy_up:
+ * A file is about to be copied up from lower layer to upper layer of
+ * overlay filesystem. Security module can prepare a set of new creds
+ * and modify as need be and return new creds. Caller will switch to
+ * new creds temporarily to create new file and release newly allocated
+ * creds.
+ * @src indicates the union dentry of file that is being copied up.
+ * @new pointer to pointer to return newly allocated creds.
+ * Returns 0 on success or a negative error code on error.
+ * @inode_copy_up_xattr:
+ * Filter the xattrs being copied up when a unioned file is copied
+ * up from a lower layer to the union/overlay layer.
+ * @name indicates the name of the xattr.
+ * Returns 0 to accept the xattr, 1 to discard the xattr, -EOPNOTSUPP if
+ * security module does not know about attribute or a negative error code
+ * to abort the copy up. Note that the caller is responsible for reading
+ * and writing the xattrs as this hook is merely a filter.
*
* Security hooks for file operations
*
int (*dentry_init_security)(struct dentry *dentry, int mode,
const struct qstr *name, void **ctx,
u32 *ctxlen);
+ int (*dentry_create_files_as)(struct dentry *dentry, int mode,
+ struct qstr *name,
+ const struct cred *old,
+ struct cred *new);
#ifdef CONFIG_SECURITY_PATH
int (*inode_listsecurity)(struct inode *inode, char *buffer,
size_t buffer_size);
void (*inode_getsecid)(struct inode *inode, u32 *secid);
+ int (*inode_copy_up)(struct dentry *src, struct cred **new);
+ int (*inode_copy_up_xattr)(const char *name);
int (*file_permission)(struct file *file, int mask);
int (*file_alloc_security)(struct file *file);
int (*kernel_act_as)(struct cred *new, u32 secid);
int (*kernel_create_files_as)(struct cred *new, struct inode *inode);
int (*kernel_module_request)(char *kmod_name);
- int (*kernel_module_from_file)(struct file *file);
int (*kernel_read_file)(struct file *file, enum kernel_read_file_id id);
int (*kernel_post_read_file)(struct file *file, char *buf, loff_t size,
enum kernel_read_file_id id);
struct list_head sb_clone_mnt_opts;
struct list_head sb_parse_opts_str;
struct list_head dentry_init_security;
+ struct list_head dentry_create_files_as;
#ifdef CONFIG_SECURITY_PATH
struct list_head path_unlink;
struct list_head path_mkdir;
struct list_head inode_setsecurity;
struct list_head inode_listsecurity;
struct list_head inode_getsecid;
+ struct list_head inode_copy_up;
+ struct list_head inode_copy_up_xattr;
struct list_head file_permission;
struct list_head file_alloc_security;
struct list_head file_free_security;
int security_dentry_init_security(struct dentry *dentry, int mode,
const struct qstr *name, void **ctx,
u32 *ctxlen);
+ int security_dentry_create_files_as(struct dentry *dentry, int mode,
+ struct qstr *name,
+ const struct cred *old,
+ struct cred *new);
int security_inode_alloc(struct inode *inode);
void security_inode_free(struct inode *inode);
int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags);
int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size);
void security_inode_getsecid(struct inode *inode, u32 *secid);
+ int security_inode_copy_up(struct dentry *src, struct cred **new);
+ int security_inode_copy_up_xattr(const char *name);
int security_file_permission(struct file *file, int mask);
int security_file_alloc(struct file *file);
void security_file_free(struct file *file);
int security_kernel_act_as(struct cred *new, u32 secid);
int security_kernel_create_files_as(struct cred *new, struct inode *inode);
int security_kernel_module_request(char *kmod_name);
-int security_kernel_module_from_file(struct file *file);
int security_kernel_read_file(struct file *file, enum kernel_read_file_id id);
int security_kernel_post_read_file(struct file *file, char *buf, loff_t size,
enum kernel_read_file_id id);
return -EOPNOTSUPP;
}
+ static inline int security_dentry_create_files_as(struct dentry *dentry,
+ int mode, struct qstr *name,
+ const struct cred *old,
+ struct cred *new)
+ {
+ return 0;
+ }
+
static inline int security_inode_init_security(struct inode *inode,
struct inode *dir,
*secid = 0;
}
+ static inline int security_inode_copy_up(struct dentry *src, struct cred **new)
+ {
+ return 0;
+ }
+
+ static inline int security_inode_copy_up_xattr(const char *name)
+ {
+ return -EOPNOTSUPP;
+ }
+
static inline int security_file_permission(struct file *file, int mask)
{
return 0;
projects / deliverable / linux.git / commitdiff
