Commit Graph

552 Commits

Author SHA1 Message Date
Jakob Unterwurzacher
e885f08746 fusefrontend: drop last remaining call into loopbackFileSystem
The only call forwarded to loopbackFileSystem was Statfs,
which is trivial to implement.

Implement it and drop loopbackFileSystem, as having it carries the
risk that a coding error bypasses the usual encryption/decryption
chain.
2019-01-13 20:27:35 +01:00
Sebastian Lackner
d44fe89ba4 fusefrontend: Do not pass unsupported flags to Faccessat on macOS.
Fixes mounting of forward mounts on macOS High Sierra.
2019-01-13 14:10:34 +01:00
Jakob Unterwurzacher
711ef81bfb macos: filter SUID and SGID bits in OpenatUser, MknodatUser, MkdiratUser
When gocryptfs runs as root, we don't want to allow people to create
SUID root files.
2019-01-13 14:05:03 +01:00
Sebastian Lackner
99e8b6d288 fusefrontend: Preserve SUID/SGID/sticky-bits in openWriteOnlyFile and Rmdir.
Fixes https://github.com/rfjakob/gocryptfs/issues/336 and
https://github.com/rfjakob/gocryptfs/issues/337.
2019-01-12 21:24:50 +01:00
Sebastian Lackner
efc280330c fusefrontend: -allow_other: Use SymlinkatUser in Symlink FUSE call.
Instead of manually adjusting the user after creating the symlink,
adjust effective permissions and let the kernel deal with it.

Related to https://github.com/rfjakob/gocryptfs/issues/338.
2019-01-12 21:22:58 +01:00
Sebastian Lackner
1fbe7798cf fusefrontend: -allow_other: Use MknodatUser in Mknod FUSE call.
Instead of manually adjusting the user and mode after creating the
device file, adjust effective permissions and let the kernel deal
with it.

Related to https://github.com/rfjakob/gocryptfs/issues/338.
2019-01-12 21:20:16 +01:00
Sebastian Lackner
a525e33eaa fusefrontend: -allow_other: Use MkdiratUser in Mkdir FUSE call.
Revert commit fcaca5fc94.

Instead of manually adjusting the user and mode after creating the
directory, adjust effective permissions and let the kernel deal with it.

Related to https://github.com/rfjakob/gocryptfs/issues/338.
2019-01-12 21:20:07 +01:00
Sebastian Lackner
03b9d65cce fusefrontend: -allow_other: Use OpenatUser in Create FUSE call.
Revert commit b22cc03c75.

Instead of manually adjusting the user and mode after creating the
file, adjust effective permissions and let the kernel deal with it.

Related to https://github.com/rfjakob/gocryptfs/issues/338.
2019-01-12 20:54:39 +01:00
Sebastian Lackner
669322482a fusefrontend: Don't chown gocryptfs.diriv files.
The current code has a risk of race-conditions, since we pass a path
containing "/" to Fchownat. We could fix this by opening a file descriptor,
however, this does not seem worth the effort. We also don't chown *.name files.
2019-01-12 20:35:50 +01:00
Sebastian Lackner
fcaca5fc94 fusefrontend: -allow_other: set file mode after chown in Mkdir().
Make sure that the directory belongs to the correct owner before users
can access it. For directories with SUID/SGID mode, there is a risk of
race-conditions when files are created before the correct owner is set.
They will then inherit the wrong user and/or group.

See https://github.com/rfjakob/gocryptfs/issues/327 for more details.
2019-01-09 20:48:00 +01:00
Sebastian Lackner
aae45b4d77 nametransform: Create *.name files with 0400 permission.
Similar to gocryptfs.iv files they are never modified.
2019-01-09 20:42:18 +01:00
Jakob Unterwurzacher
b22cc03c75 fusefrontend: -allow_other: set file mode *after* chown in Create()
Reported by @slackner at https://github.com/rfjakob/gocryptfs/issues/327 :

Possible race-conditions between file creation and Fchownat

* Assume a system contains a gocryptfs mount as root user
  with -allow_other
* As a regular user create a new file with mode containing
  the SUID flag and write access for other users
* Before gocryptfs executes the Fchownat call, try to open
  the file again, write some exploit code to it, and try to run it.

For a short time, the file is owned by root and has the SUID flag, so
this is pretty dangerous.
2019-01-08 21:50:10 +01:00
Sebastian Lackner
4170ef00f3 syscallcompat: Implement workaround for Fchmodat with AT_SYMLINK_NOFOLLOW.
Fixes https://github.com/rfjakob/gocryptfs/issues/259
2019-01-07 23:07:53 +01:00
Jakob Unterwurzacher
8253c55386 tests: add Fchmodat test
Test that we handle symlinks correctly.
2019-01-07 23:07:53 +01:00
Sebastian Lackner
57a52d6aef fusefrontend: Clarify access mode check related to O_WRONLY handling.
Use O_ACCMODE mask in openWriteOnlyFile for improved readability.
2019-01-07 21:25:23 +01:00
Sebastian Lackner
2332462e78 fusefrontend: Filter O_CREAT in mangleOpenFlags. 2019-01-07 21:19:13 +01:00
Sebastian Lackner
aa2fa24c42 fusefrontend: Check result of Fchmod syscall.
Fixes https://github.com/rfjakob/gocryptfs/issues/328
2019-01-06 21:00:17 +01:00
Sebastian Lackner
40d2427fd7 fusefrontend: Fix computation of cipherSz in Allocate FUSE call.
Do not use PlainSizeToCipherSize() since this adds the 18 bytes file header.

Partially fixes https://github.com/rfjakob/gocryptfs/issues/311
2019-01-06 20:56:59 +01:00
Sebastian Lackner
8310dd95be fusefrontend: Properly convert plaintext <-> ciphertext offsets in SeekData().
Fixes https://github.com/rfjakob/gocryptfs/issues/304
2019-01-06 12:21:54 +01:00
Sebastian Lackner
7e05e809b7 main: Run 'ensure fds' code early during the program startup.
The files are apparently processed in alphabetic order, so cli_args.go is
processed before main.go. In order to run before the go-fuse imports, put
the 'ensure fds' code in a separate package. Debug messages are omitted
to avoid additional imports (that might contain other code messing up our
file descriptors).
2019-01-05 16:12:16 +01:00
Jakob Unterwurzacher
ad15ad9985 main: ensure fds 0,1,2 are always open
The Go stdlib, as well as the gocryptfs code, relies on the fact
that fds 0,1,2 are always open.

See https://github.com/rfjakob/gocryptfs/issues/320 for details.
2019-01-05 14:17:51 +01:00
Sebastian Lackner
5055f39bd5 fusefrontend: Allow to set/remove xattr on directory without read permission.
Setting/removing extended attributes on directories was partially fixed with
commit eff35e60b6. However, on most file systems
it is also possible to do these operations without read access (see tests).

Since we cannot open a write-access fd to a directory, we have to use the
/proc/self/fd trick (already used for ListXAttr) for the other operations aswell.
For simplicity, let's separate the Linux and Darwin code again (basically revert
commit f320b76fd1), and always use the
/proc/self/fd trick on Linux. On Darwin we use the best-effort approach with
openBackingFile() as a fallback.

More discussion about the available options is available in
https://github.com/rfjakob/gocryptfs/issues/308.
2019-01-05 12:34:40 +01:00
Sebastian Lackner
f17721c364 A few more spelling fixes. 2019-01-05 12:27:55 +01:00
Jakob Unterwurzacher
65eded4a22 tests: bump maxCacheFds to 3
As the dirCache now has 3 entries, the tests should accept
up to 3 extra fds without declaring an fd leak.
2019-01-04 23:50:01 +01:00
Jakob Unterwurzacher
c32066c5b0 fusefrontend: fix fd leak in dirCache
The missing break meant that we may find a second
hit in the cache, Dup() a second fd, and leak the first
one.

Thanks @slackner for finding this.
2019-01-04 23:35:48 +01:00
Jakob Unterwurzacher
8074f12beb nametransform: ReadDirIVAt: return raw syscall error
Otherwise this can happen, as triggered by xfstests generic/011:

  go-fuse: can't convert error type: openat failed: too many open files

The app then gets a misleading "Function not implemented" error.
2019-01-04 23:21:27 +01:00
Jakob Unterwurzacher
3473a84963 fusefrontend: print warning when Create() runs out of file descriptors
We alread have this warning in Open(), but xfstests generic/488
causes "too many open files" via Create. Add the same message so
the user sees what is going on.
2019-01-04 23:15:04 +01:00
Jakob Unterwurzacher
eff35e60b6 fusefrontend: fix setting xattrs on directories
Directories cannot be opened read-write. Retry with RDONLY.
2019-01-04 22:22:24 +01:00
Jakob Unterwurzacher
3365cfc02b fusefrontend: disable dirCache stats printing
This was inadvertedly kept enabled after benchmarking.
2019-01-04 22:07:02 +01:00
Jakob Unterwurzacher
c0a7a14cde fusefrontend: upgrade to three-entry dirCache
3 entries should work well for up to three parallel users.
It works well for extractloop.bash (two parallel tar extracts).
2019-01-04 21:45:03 +01:00
Sebastian Lackner
117dc3f2cc fusefrontend_reverse: Fix redeclaration of 'entries' variable.
Go version go1.10.7 linux/amd64 complains with:

 internal/fusefrontend_reverse/rfs.go:333: declaration of "entries" shadows
 declaration at internal/fusefrontend_reverse/rfs.go:327
2019-01-04 20:11:45 +01:00
Jakob Unterwurzacher
6b94f5ef51 reverse mode: -exclude: filter out excluded .name files
Fixes https://github.com/rfjakob/gocryptfs/issues/286 :

While the actual file is properly excluded, the * .name file is still leaked in the directory listing:

```
drwxr-xr-x 2 sebastian sebastian 4,0K Dez 17 14:58 .
drwxr-xr-x 7 sebastian sebastian 4,0K Dez 17 14:45 ..
-r-------- 1 sebastian sebastian  408 Dez 17 14:56 gocryptfs.conf
-r--r--r-- 1 sebastian sebastian   16 Dez 17 14:58 gocryptfs.diriv
-r--r--r-- 1 sebastian sebastian  320 Dez 17 14:58 gocryptfs.longname.3vZ_r3eDPb1_fL3j5VA4rd_bcKWLKT9eaxOVIGK5HFA.name
```
2019-01-04 17:59:00 +01:00
Jakob Unterwurzacher
75a3e2c2ee reverse mode: fix "-exclude" in "-plaintextnames" dir listings
Excluded files showed up in directory listing like this:

 drwxr-xr-x 2 sebastian sebastian 4,0K Dez 17 14:48 .
 drwxr-xr-x 7 sebastian sebastian 4,0K Dez 17 14:45 ..
 -????????? ? ?         ?            ?            ? abcd
 -r-------- 1 sebastian sebastian  366 Dez 17 14:45 gocryptfs.conf

Fixes https://github.com/rfjakob/gocryptfs/issues/285
2019-01-04 17:36:06 +01:00
Sebastian Lackner
acf7e52022 fusefrontend: Allow to create sparse file of size 4096.
When the old size is zero, there are no existing blocks to merge the
new data with. Directly use Ftruncate if the size is block-aligned.

Fixes https://github.com/rfjakob/gocryptfs/issues/305
2019-01-04 01:38:47 +01:00
Sebastian Lackner
ab169443fd A few more spelling fixes.
Found with the 'codespell' utility.
2019-01-04 01:23:44 +01:00
Sebastian Lackner
a1ba4b6576 Omit syscall.O_RDONLY flag when passing O_PATH.
When O_PATH is specified in flags, flag bits other than O_CLOEXEC, O_DIRECTORY,
and O_NOFOLLOW are ignored.
2019-01-03 18:24:05 +01:00
Sebastian Lackner
0414ef2572 fusefrontend: Use appropriate flags in decryptPathAt. 2019-01-03 18:24:05 +01:00
Sebastian Lackner
c0640ff3ef fusefrontend: Open directory with syscall.O_DIRECTORY in OpenDir. 2019-01-03 18:24:05 +01:00
Sebastian Lackner
078a431493 fusefrontend: Open directory with syscall.O_DIRECTORY in Rmdir. 2019-01-03 18:24:05 +01:00
Sebastian Lackner
885a341df6 fusefrontend: Do not Clear cache at end of Rmdir function.
We already do 'defer fs.dirCache.Clear()', so this is no longer required.
2019-01-03 18:24:05 +01:00
Sebastian Lackner
61241b0588 nametransform: Add implicit syscall.O_RDONLY flag. 2019-01-03 18:24:05 +01:00
Sebastian Lackner
927b3ce4cf syscallcompat: Use O_PATH to open base directory.
Also remove some unnecessary flags: When O_PATH is specified in flags, flag
bits other than O_CLOEXEC, O_DIRECTORY, and O_NOFOLLOW are ignored.
2019-01-03 18:24:05 +01:00
Sebastian Lackner
d86f9914ac fusefrontend: Remove debug code.
This code was accidentially added in 4f66d66755.
2019-01-03 18:24:05 +01:00
Jakob Unterwurzacher
fcdb4bec09 fusefronted: dirCache: fix bug handling ""
Bug looked like this:

  $ ls -l .
  total 0
  drwxrwxr-x. 2 jakob jakob 60 Jan  3 15:42 foo
  -rw-rw-r--. 1 jakob jakob  0 Jan  3 15:46 x

  $ ls -l .
  ls: cannot access '.': No such file or directory

(only happened when "" was in the dirCache)
2019-01-03 15:59:54 +01:00
Jakob Unterwurzacher
4f66d66755 fusefrontend: add dirCache 2019-01-03 15:31:13 +01:00
Jakob Unterwurzacher
f6dad8d0fa nametransform: simplify WriteDirIV to WriteDirIVAt
Un-spaghettify the function and let the callers open
the directory.
2019-01-03 15:31:13 +01:00
Jakob Unterwurzacher
0fd7637624 fusefrontend: use O_RDONLY in the ListXAttr fallback path
Copy-paste error.

https://github.com/rfjakob/gocryptfs/issues/308
2019-01-02 22:20:44 +01:00
Jakob Unterwurzacher
352f3147c5 fusefrontend: move openBackingDir into its own file
This function is in all fastpaths, will get a cache, and needs
its own file.
renamed:    internal/fusefrontend/names.go -> internal/fusefrontend/openbackingdir.go
renamed:    internal/fusefrontend/names_test.go -> internal/fusefrontend/openbackingdir_test.go
2019-01-02 21:52:52 +01:00
Jakob Unterwurzacher
2b12bba274 fusefronted: make EncryptPath symlink-safe
Finally allows us to delete EncryptPathDirIV.
2019-01-02 21:45:40 +01:00
Jakob Unterwurzacher
b214be5e3f fusefrontend: xattr: fix operations on files without read permissions
* listxattr is fixed via the /proc/self/fd trick
* setxattr,removexattr are fixed by opening the file O_WRONLY

Fixes https://github.com/rfjakob/gocryptfs/issues/308
2019-01-02 20:48:46 +01:00