dir.c (92a8780e1136c5ca0c7ed940000d399943d1576e) dir.c (87729a5514e855ce2c71e3e33833a106b8caf2ae)
1/*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
4
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7*/
8

--- 397 unchanged lines hidden (view full) ---

406 fuse_change_attributes(inode, &arg.attr);
407 fi->i_time = time_to_jiffies(arg.attr_valid,
408 arg.attr_valid_nsec);
409 }
410 }
411 return err;
412}
413
1/*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
4
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7*/
8

--- 397 unchanged lines hidden (view full) ---

406 fuse_change_attributes(inode, &arg.attr);
407 fi->i_time = time_to_jiffies(arg.attr_valid,
408 arg.attr_valid_nsec);
409 }
410 }
411 return err;
412}
413
414/*
415 * Calling into a user-controlled filesystem gives the filesystem
416 * daemon ptrace-like capabilities over the requester process. This
417 * means, that the filesystem daemon is able to record the exact
418 * filesystem operations performed, and can also control the behavior
419 * of the requester process in otherwise impossible ways. For example
420 * it can delay the operation for arbitrary length of time allowing
421 * DoS against the requester.
422 *
423 * For this reason only those processes can call into the filesystem,
424 * for which the owner of the mount has ptrace privilege. This
425 * excludes processes started by other users, suid or sgid processes.
426 */
427static int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task)
428{
429 if (fc->flags & FUSE_ALLOW_OTHER)
430 return 1;
431
432 if (task->euid == fc->user_id &&
433 task->suid == fc->user_id &&
434 task->uid == fc->user_id &&
435 task->egid == fc->group_id &&
436 task->sgid == fc->group_id &&
437 task->gid == fc->group_id)
438 return 1;
439
440 return 0;
441}
442
414static int fuse_revalidate(struct dentry *entry)
415{
416 struct inode *inode = entry->d_inode;
417 struct fuse_inode *fi = get_fuse_inode(inode);
418 struct fuse_conn *fc = get_fuse_conn(inode);
419
443static int fuse_revalidate(struct dentry *entry)
444{
445 struct inode *inode = entry->d_inode;
446 struct fuse_inode *fi = get_fuse_inode(inode);
447 struct fuse_conn *fc = get_fuse_conn(inode);
448
420 if (get_node_id(inode) == FUSE_ROOT_ID) {
421 if (!(fc->flags & FUSE_ALLOW_OTHER) &&
422 current->fsuid != fc->user_id)
423 return -EACCES;
424 } else if (time_before_eq(jiffies, fi->i_time))
449 if (!fuse_allow_task(fc, current))
450 return -EACCES;
451 if (get_node_id(inode) != FUSE_ROOT_ID &&
452 time_before_eq(jiffies, fi->i_time))
425 return 0;
426
427 return fuse_do_getattr(inode);
428}
429
430static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
431{
432 struct fuse_conn *fc = get_fuse_conn(inode);
433
453 return 0;
454
455 return fuse_do_getattr(inode);
456}
457
458static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
459{
460 struct fuse_conn *fc = get_fuse_conn(inode);
461
434 if (!(fc->flags & FUSE_ALLOW_OTHER) && current->fsuid != fc->user_id)
462 if (!fuse_allow_task(fc, current))
435 return -EACCES;
436 else if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
437 int err = generic_permission(inode, mask, NULL);
438
439 /* If permission is denied, try to refresh file
440 attributes. This is also needed, because the root
441 node will at first have no permissions */
442 if (err == -EACCES) {

--- 539 unchanged lines hidden --- 		463 return -EACCES;
464 else if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
465 int err = generic_permission(inode, mask, NULL);
466
467 /* If permission is denied, try to refresh file
468 attributes. This is also needed, because the root
469 node will at first have no permissions */
470 if (err == -EACCES) {

--- 539 unchanged lines hidden ---