Commit Graph

62 Commits

Author SHA1 Message Date
Jakob Unterwurzacher
e4148028af fusefrontend: warn about missing diriv
The comment is outdated, at this point, we should
really not get any errors from ReadDirIVAt.

The change is best seen when running the fsck tests. Before:

  fsck: error opening dir "missing_diriv": 2=no such file or directory

After:

  OpenDir "K2m0E6qzIfoLkVZJanoUiQ": could not read gocryptfs.diriv: no such file or directory
  fsck: error opening dir "missing_diriv": 5=input/output error

See https://github.com/rfjakob/gocryptfs/issues/403 , where
the extra info would have been helpful.
2019-11-03 20:38:15 +01:00
Jakob Unterwurzacher
93939961f5 fusefrontend: don't return EIO on directory with corrupt file names
This was meant as a way to inform the user that
something is very wrong, however, users are hitting
the condition on MacOS due to ".DS_Store" files, and
also on NFS due to ".nfsXXX" files.

Drop the whole thing as it seems to cause more pain
than gain.

Fixes https://github.com/rfjakob/gocryptfs/issues/431
2019-11-03 20:12:05 +01:00
Jakob Unterwurzacher
7d81494a64 fusefrontend: get rid of last hardcoded "gocryptfs.diriv" instances
Makes it easier to change the name (as some people want to):
https://github.com/rfjakob/gocryptfs/issues/37
2019-04-09 20:51:33 +02:00
Jakob Unterwurzacher
962c523644 fusefrontend: ensure directories without W or X perms can be deleted
This fixed the "Permission denied" bug, but still has the problem that
the directory may be replaced behind our back. Mitigated by the fact
that we skip the workaround when running as root with -allow_other.

https://github.com/rfjakob/gocryptfs/issues/354
2019-01-20 14:29:28 +01:00
Jakob Unterwurzacher
a7d59032d3 syscallcompat: rework Fchmodat to FchmodatNofollow
We never want Fchmodat to follow symlinks, so follow what
Qemu does, and call our function FchmodatNofollow.
2019-01-14 21:54:16 +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
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
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
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
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
abbdaa8ea4 fusefrontend: fix compile failure on Darwin
Failure was:

 + GOOS=darwin
 + GOARCH=amd64
 + go build -tags without_openssl
 # github.com/rfjakob/gocryptfs/internal/fusefrontend
 internal/fusefrontend/fs_dir.go:159:60: cannot use origMode | 448 (type uint16) as type uint32 in argument to syscallcompat.Fchmodat
 internal/fusefrontend/fs_dir.go:170:33: cannot use origMode (type uint16) as type uint32 in argument to syscallcompat.Fchmodat
2019-01-01 16:24:25 +01:00
Jakob Unterwurzacher
436f918c21 fusefrontend: make Rmdir symlink-safe
Now uses Unlinkat.
2019-01-01 16:24:25 +01:00
Jakob Unterwurzacher
2de3851abd nametransform: rename WriteLongName() -> WriteLongNameAt()
And also rename DeleteLongName() -> DeleteLongNameAt(). The
naming follow the names open the openat() etc syscalls.
2019-01-01 16:24:25 +01:00
Jakob Unterwurzacher
21f1f858b9 fusefrontend: make OpenDir() symlink-safe
Interestingly, little or no performance impact:

$ ./benchmark.bash
Testing gocryptfs at /tmp/benchmark.bash.39W: gocryptfs v1.6-42-g30c2349-dirty; go-fuse v20170619-66-g6df8ddc; 2018-11-04 go1.11
Downloading linux-3.0.tar.gz
/tmp/linux-3.0.tar.gz                  100%[=========================================================================>]  92.20M  2.93MB/s    in 31s
2018-11-04 21:44:44 URL:https://cdn.kernel.org/pub/linux/kernel/v3.0/linux-3.0.tar.gz [96675825/96675825] -> "/tmp/linux-3.0.tar.gz" [1]
WRITE: 262144000 bytes (262 MB, 250 MiB) copied, 1.1808 s, 222 MB/s
READ:  262144000 bytes (262 MB, 250 MiB) copied, 0.866438 s, 303 MB/s
UNTAR: 24.745
MD5:   12.050
LS:    3.525
RM:    9.544

Note: kernel has been updated:

$ uname -a
Linux brikett 4.18.16-200.fc28.x86_64 #1 SMP Sat Oct 20 23:53:47 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
2019-01-01 16:24:25 +01:00
Jakob Unterwurzacher
0e2e7c13cf fusefrontend: mark symlink-safe FUSE calls
Document which FUSE calls are already symlink-safe in
the function comment.
2019-01-01 16:24:09 +01:00
Jakob Unterwurzacher
c09bf1f228 fusefrontend: make DecryptPath() symlink-safe
DecryptPath is now symlink-safe through the use of *at()
functions.
2019-01-01 16:24:09 +01:00
Sebastian Lackner
1ced0b192e fusefrontend: Don't treat Fchownat error as failure in Mkdir.
The directory was already created, so return success even if Fchownat fails.
The same error handling is already used if fs.args.PlaintextNames is false.
2018-12-27 15:16:00 +01:00
Sebastian Lackner
5918884926 fusefrontend: Check the correct 'err' variable. 2018-12-27 15:11:23 +01:00
Jakob Unterwurzacher
c270b21efc fusefrontend: get rid of os.File* wrapping
Directly use int file descriptors for the dirfd
and get rid of one level of indirection.
2018-09-23 12:17:26 +02:00
Jakob Unterwurzacher
e8d8ae54d3 fusefrontend: use OpenDirNofollow in openBackingDir
Rename openBackingPath to openBackingDir and use OpenDirNofollow
to be safe against symlink races. Note that openBackingDir is
not used in several important code paths like Create().

But it is used in Unlink, and the performance impact in the RM benchmark
to be acceptable:

Before

	$ ./benchmark.bash
	Testing gocryptfs at /tmp/benchmark.bash.bYO: gocryptfs v1.6-12-g930c37e-dirty; go-fuse v20170619-49-gb11e293; 2018-09-08 go1.10.3
	WRITE: 262144000 bytes (262 MB, 250 MiB) copied, 1.07979 s, 243 MB/s
	READ:  262144000 bytes (262 MB, 250 MiB) copied, 0.882413 s, 297 MB/s
	UNTAR: 16.703
	MD5:   7.606
	LS:    1.349
	RM:    3.237

After

	$ ./benchmark.bash
	Testing gocryptfs at /tmp/benchmark.bash.jK3: gocryptfs v1.6-13-g84d6faf-dirty; go-fuse v20170619-49-gb11e293; 2018-09-08 go1.10.3
	WRITE: 262144000 bytes (262 MB, 250 MiB) copied, 1.06261 s, 247 MB/s
	READ:  262144000 bytes (262 MB, 250 MiB) copied, 0.947228 s, 277 MB/s
	UNTAR: 17.197
	MD5:   7.540
	LS:    1.364
	RM:    3.410
2018-09-08 19:27:33 +02:00
Jakob Unterwurzacher
1a18d8e609 fsck: rename "CorruptItems" channel to "MitigatedCorruptions"
Make it clear that this channel is only used to report corruptions
that are transparently mitigated and do not return an error to
the user.
2018-07-01 20:56:22 +02:00
Jakob Unterwurzacher
4e5783591f fsck: report skipped corrupt files
OpenDir and ListXAttr skip over corrupt entries,
readFileID treats files the are too small as empty.
This improves usability in the face of corruption,
but hides the problem in a log message instead of
putting it in the return code.

Create a channel to report these corruptions to fsck
so it can report them to the user.

Also update the manpage and the changelog with the -fsck option.

Closes https://github.com/rfjakob/gocryptfs/issues/191
2018-04-03 21:24:48 +02:00
Jakob Unterwurzacher
b6c8960b01 fsck: clean up log output
Make sure we get only 1 warning output per
problem.

Also, add new corruption types to broken_fs_v1.4.
2018-04-02 18:32:30 +02:00
Jakob Unterwurzacher
ea51837361 fusefrontend: drop unused haveGetdents warning
We don't actually print that warning anymore.
2018-01-25 09:06:06 +01:00
Jakob Unterwurzacher
70bcf58a9b syscallcompat: convert Getdents to fd input, add emulation
Now that we have Fstatat we can use it in Getdents to
get rid of the path name.

Also, add an emulated version of getdents for MacOS. This allows
to drop the !HaveGetdents special cases from fusefrontend.

Modify the getdents test to test both native getdents and the emulated
version.
2017-12-03 19:33:26 +01:00
Sebastian Lackner
9bcde0c09e fusefrontend: Improve documentation of mkdirWithIv and WriteDirIV
As requested in https://github.com/rfjakob/gocryptfs/pull/179
2017-12-01 09:41:52 +01:00
Jakob Unterwurzacher
e97c23e083 syscallcompat: check that we get NOFOLLOW wherever possible
...and fix the instances where the AT_SYMLINK_NOFOLLOW /
O_NOFOLLOW / O_EXCL flag was missing.
2017-11-30 19:40:53 +01:00
Sebastian Lackner
614745ee57 fusefrontend: allow_other: close race between mkdir and chown
Fixes the same problem as described in 72b975867a,
except for directories instead of device nodes.
2017-11-29 13:28:04 +01:00
Sebastian Lackner
0f44c617d0 syscallcompat: Introduce unlinkat syscall with flags argument 2017-11-29 12:41:23 +01:00
Sebastian Lackner
95870e841e fusefrontend: Skip gocryptfs.diriv handling when directory was deleted successfully
Fixes https://github.com/rfjakob/gocryptfs/issues/171

Steps to reproduce:

* Create a regular forward mount point
* Create a new directory in the mount point
* Manually delete the gocryptfs.diriv file from the corresponding ciphertext
  directory
* Attempt to delete the directory with 'rmdir <dirname>'

Although the code explicitly checks for empty directories, it will still attempt
to move the non-existent gocryptfs.diriv file and fails with:

    rmdir: failed to remove '<dirname>': No such file or directory
2017-11-25 16:20:00 +01:00
Jakob Unterwurzacher
604b0779d4 macos: automatically remove .DS_Store on Rmdir
MacOS sprinkles .DS_Store files everywhere. This is hard to avoid for
users, so handle it transparently in Rmdir().

Mitigates https://github.com/rfjakob/gocryptfs/issues/140
2017-09-05 22:47:15 +02:00
Jakob Unterwurzacher
6f3b65d924 fusefrontend: reorder logic in Rmdir to get rid of one indentation level
Handle the errors first so that the normal code path is not indented.

This should not cause any behavoir changes.
2017-09-05 22:10:08 +02:00
Jakob Unterwurzacher
3a5a783b54 macos: don't throw IO errors because of .DS_Store files
MacOS creates lots of these files, and if the directory is otherwise
empty, we would throw an IO error to the unsuspecting user.

With this patch, we log a warning, but otherwise pretend we did not
see it.

Mitigates https://github.com/rfjakob/gocryptfs/issues/140
2017-09-05 21:47:05 +02:00
Jakob Unterwurzacher
538cae610c syscallcompat: Getdents: warn once if we get DT_UNKNOWN
...and if Getdents is not available at all.

Due to this warning I now know that SSHFS always returns DT_UNKNOWN:

    gocryptfs[8129]: Getdents: convertDType: received DT_UNKNOWN, falling back to Lstat

This behavoir is confirmed at http://ahefner.livejournal.com/16875.html:

    "With sshfs, I finally found that obscure case. The dtype is always set to DT_UNKNOWN [...]"
2017-09-03 15:05:54 +02:00
Jakob Unterwurzacher
276567eb13 fusefrontend: use DirIVCache in OpenDir()
Previously, OpenDir() did not use the cache at all, missing
an opportunity to speed up repeated directory reads.
2017-09-03 13:59:53 +02:00
Jakob Unterwurzacher
989b880989 fusefrontend: use Getdents if available
Getdents avoids calling Lstat on each file.
2017-08-15 19:04:02 +02:00
Jakob Unterwurzacher
e827763f2e nametransform: harden name decryption against invalid input
This fixes a few issues I have found reviewing the code:

1) Limit the amount of data ReadLongName() will read. Previously,
you could send gocryptfs into out-of-memory by symlinking
gocryptfs.diriv to /dev/zero.

2) Handle the empty input case in unPad16() by returning an
error. Previously, it would panic with an out-of-bounds array
read. It is unclear to me if this could actually be triggered.

3) Reject empty names after base64-decoding in DecryptName().
An empty name crashes emeCipher.Decrypt().
It is unclear to me if B64.DecodeString() can actually return
a non-error empty result, but let's guard against it anyway.
2017-05-23 21:26:38 +02:00
Jakob Unterwurzacher
26881538e1 nametranform, fusefrontend: better errors on invalid names
nametransform.DecryptName() now always returns syscall.EBADMSG if
the name was invalid.

fusefrontend.OpenDir error messages have been normalized.
2017-05-07 20:58:27 +02:00
Jakob Unterwurzacher
a66440c668 fusefrontend: use Lchown when preserving owner
This prevents (unlikely) symlink race attacks
2016-11-28 22:46:04 +01:00
Jakob Unterwurzacher
35219d0022 fusefrontend: log missing gocryptfs.diriv
This can happen during normal operation when the directory has
been deleted concurrently. But it can also mean that the
gocryptfs.diriv is missing due to an error, so log the event
at "info" level.
2016-10-16 15:04:59 +02:00
Jakob Unterwurzacher
828f718483 fusefrontend: Also preserve the owner in Mkdir
This already worked for files but was missing for dirs.
2016-10-10 08:53:29 +02:00
Valient Gough
b764917cd5 lint fixes 2016-10-04 23:18:33 +02:00
Jakob Unterwurzacher
d8524c7369 syscallcompat: OSX: add Unlinkat wrapper
Also, replace remaining naked syscall.Openat calls.
2016-07-03 20:17:40 +02:00
Jakob Unterwurzacher
79851bf6cc syscallcompat: OSX: add Renamat wrapper
Adds a poor man's renameat implementation for OSX.
2016-07-03 20:05:32 +02:00
Jakob Unterwurzacher
e574a6cc1f nametransform: hide detailed padding error behind the debug flag
unPad16 returns detailed errors including the position of the
incorrect bytes. Kill a possible padding oracle by lumping
everything into a generic error.

The detailed error is only logged if debug is active.
2016-07-03 15:35:58 +02:00
Jakob Unterwurzacher
3288d98703 fusefrontend: fix PlaintextNames versions of Mkdir, Rmdir
The "!fs.args.DirIV" special case was removed by b17f0465c7
but that, by accident, also removed the handling for
PlaintextNames.

Re-add it as an explicit PlaintextNames special case.

Also adds support for removing directories that miss their
gocryptfs.diriv file for some reason.
2016-06-27 00:27:36 +02:00