user/sven/linux.git/fs/fuse, branch v3.2.86

fuse: fix clearing suid, sgid for chown()

2017-02-23T03:51:02Z

commit c01638f5d919728f565bf8b5e0a6a159642df0d9 upstream. Basically, the pjdfstests set the ownership of a file to 06555, and then chowns it (as root) to a new uid/gid. Prior to commit a09f99eddef4 ("fuse: fix killing s[ug]id in setattr"), fuse would send down a setattr with both the uid/gid change and a new mode. Now, it just sends down the uid/gid change. Technically this is NOTABUG, since POSIX doesn't _require_ that we clear these bits for a privileged process, but Linux (wisely) has done that and I think we don't want to change that behavior here. This is caused by the use of should_remove_suid(), which will always return 0 when the process has CAP_FSETID. In fact we really don't need to be calling should_remove_suid() at all, since we've already been indicated that we should remove the suid, we just don't want to use a (very) stale mode for that. This patch should fix the above as well as simplify the logic. Reported-by: Jeff Layton Signed-off-by: Miklos Szeredi Fixes: a09f99eddef4 ("fuse: fix killing s[ug]id in setattr") Reviewed-by: Jeff Layton [bwh: Backported to 3.2: adjust context, indentation] Signed-off-by: Ben Hutchings

fuse: listxattr: verify xattr list

2017-02-23T03:50:52Z

commit cb3ae6d25a5471be62bfe6ac1fccc0e91edeaba0 upstream. Make sure userspace filesystem is returning a well formed list of xattr names (zero or more nonzero length, null terminated strings). [Michael Theall: only verify in the nonzero size case] Signed-off-by: Miklos Szeredi [bwh: Backported to 3.2: adjust context, indentation] Signed-off-by: Ben Hutchings

fuse: fix killing s[ug]id in setattr

2017-02-23T03:50:52Z

commit a09f99eddef44035ec764075a37bace8181bec38 upstream. Fuse allowed VFS to set mode in setattr in order to clear suid/sgid on chown and truncate, and (since writeback_cache) write. The problem with this is that it'll potentially restore a stale mode. The poper fix would be to let the filesystems do the suid/sgid clearing on the relevant operations. Possibly some are already doing it but there's no way we can detect this. So fix this by refreshing and recalculating the mode. Do this only if ATTR_KILL_S[UG]ID is set to not destroy performance for writes. This is still racy but the size of the window is reduced. Signed-off-by: Miklos Szeredi [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings

fuse: invalidate dir dentry after chmod

2017-02-23T03:50:52Z

commit 5e2b8828ff3d79aca8c3a1730652758753205b61 upstream. Without "default_permissions" the userspace filesystem's lookup operation needs to perform the check for search permission on the directory. If directory does not allow search for everyone (this is quite rare) then userspace filesystem has to set entry timeout to zero to make sure permissions are always performed. Changing the mode bits of the directory should also invalidate the (previously cached) dentry to make sure the next lookup will have a chance of updating the timeout, if needed. Reported-by: Jean-Pierre André Signed-off-by: Miklos Szeredi [bwh: Backported to 3.2: - Adjust context - Open-code d_is_dir()] Signed-off-by: Ben Hutchings

fs: Give dentry to inode_change_ok() instead of inode

2016-11-20T01:01:43Z

commit 31051c85b5e2aaaf6315f74c72a732673632a905 upstream. inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks. Reviewed-by: Christoph Hellwig Signed-off-by: Jan Kara [bwh: Backported to 3.2: - Drop changes to f2fs, lustre, orangefs, overlayfs - Adjust filenames, context - In nfsd, pass dentry to nfsd_sanitize_attrs() - In xfs, pass dentry to xfs_change_file_space(), xfs_set_mode(), xfs_setattr_nonsize(), and xfs_setattr_size() - Update ext3 as well - Mark pohmelfs as BROKEN; it's long dead upstream] Signed-off-by: Ben Hutchings

fuse: break infinite loop in fuse_fill_write_pages()

2015-12-30T02:25:54Z

commit 3ca8138f014a913f98e6ef40e939868e1e9ea876 upstream. I got a report about unkillable task eating CPU. Further investigation shows, that the problem is in the fuse_fill_write_pages() function. If iov's first segment has zero length, we get an infinite loop, because we never reach iov_iter_advance() call. Fix this by calling iov_iter_advance() before repeating an attempt to copy data from userspace. A similar problem is described in 124d3b7041f ("fix writev regression: pan hanging unkillable and un-straceable"). If zero-length segmend is followed by segment with invalid address, iov_iter_fault_in_readable() checks only first segment (zero-length), iov_iter_copy_from_user_atomic() skips it, fails at second and returns zero -> goto again without skipping zero-length segment. Patch calls iov_iter_advance() before goto again: we'll skip zero-length segment at second iteraction and iov_iter_fault_in_readable() will detect invalid address. Special thanks to Konstantin Khlebnikov, who helped a lot with the commit description. Cc: Andrew Morton Cc: Maxim Patlasov Cc: Konstantin Khlebnikov Signed-off-by: Roman Gushchin Signed-off-by: Miklos Szeredi Fixes: ea9b9907b82a ("fuse: implement perform_write") Signed-off-by: Ben Hutchings

fuse: initialize fc->release before calling it

2015-08-12T14:33:18Z

commit 0ad0b3255a08020eaf50e34ef0d6df5bdf5e09ed upstream. fc->release is called from fuse_conn_put() which was used in the error cleanup before fc->release was initialized. [Jeremiah Mahler : assign fc->release after calling fuse_conn_init(fc) instead of before.] Signed-off-by: Miklos Szeredi Fixes: a325f9b92273 ("fuse: update fuse_conn_init() and separate out fuse_conn_kill()") Signed-off-by: Ben Hutchings

fuse: set stolen page uptodate

2015-05-09T22:16:25Z

commit aa991b3b267e24f578bac7b09cc57579b660304b upstream. Regular pipe buffers' ->steal method (generic_pipe_buf_steal()) doesn't set PG_uptodate. Don't warn on this condition, just set the uptodate flag. Signed-off-by: Miklos Szeredi Signed-off-by: Ben Hutchings

fuse: notify: don't move pages

2015-05-09T22:16:25Z

commit 0d2783626a53d4c922f82d51fa675cb5d13f0d36 upstream. fuse_try_move_page() is not prepared for replacing pages that have already been read. Reported-by: Al Viro Signed-off-by: Miklos Szeredi Signed-off-by: Ben Hutchings

fuse: handle large user and group ID

2014-08-06T17:07:36Z

commit 233a01fa9c4c7c41238537e8db8434667ff28a2f upstream. If the number in "user_id=N" or "group_id=N" mount options was larger than INT_MAX then fuse returned EINVAL. Fix this to handle all valid uid/gid values. Signed-off-by: Miklos Szeredi [bwh: Backported to 3.2: no user namespace conversion] Signed-off-by: Ben Hutchings