Commit Graph

215 Commits

Author SHA1 Message Date
Linus Torvalds 7d6beb71da idmapped-mounts-v5.12
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCYCegywAKCRCRxhvAZXjc
 ouJ6AQDlf+7jCQlQdeKKoN9QDFfMzG1ooemat36EpRRTONaGuAD8D9A4sUsG4+5f
 4IU5Lj9oY4DEmF8HenbWK2ZHsesL2Qg=
 =yPaw
 -----END PGP SIGNATURE-----

Merge tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull idmapped mounts from Christian Brauner:
 "This introduces idmapped mounts which has been in the making for some
  time. Simply put, different mounts can expose the same file or
  directory with different ownership. This initial implementation comes
  with ports for fat, ext4 and with Christoph's port for xfs with more
  filesystems being actively worked on by independent people and
  maintainers.

  Idmapping mounts handle a wide range of long standing use-cases. Here
  are just a few:

   - Idmapped mounts make it possible to easily share files between
     multiple users or multiple machines especially in complex
     scenarios. For example, idmapped mounts will be used in the
     implementation of portable home directories in
     systemd-homed.service(8) where they allow users to move their home
     directory to an external storage device and use it on multiple
     computers where they are assigned different uids and gids. This
     effectively makes it possible to assign random uids and gids at
     login time.

   - It is possible to share files from the host with unprivileged
     containers without having to change ownership permanently through
     chown(2).

   - It is possible to idmap a container's rootfs and without having to
     mangle every file. For example, Chromebooks use it to share the
     user's Download folder with their unprivileged containers in their
     Linux subsystem.

   - It is possible to share files between containers with
     non-overlapping idmappings.

   - Filesystem that lack a proper concept of ownership such as fat can
     use idmapped mounts to implement discretionary access (DAC)
     permission checking.

   - They allow users to efficiently changing ownership on a per-mount
     basis without having to (recursively) chown(2) all files. In
     contrast to chown (2) changing ownership of large sets of files is
     instantenous with idmapped mounts. This is especially useful when
     ownership of a whole root filesystem of a virtual machine or
     container is changed. With idmapped mounts a single syscall
     mount_setattr syscall will be sufficient to change the ownership of
     all files.

   - Idmapped mounts always take the current ownership into account as
     idmappings specify what a given uid or gid is supposed to be mapped
     to. This contrasts with the chown(2) syscall which cannot by itself
     take the current ownership of the files it changes into account. It
     simply changes the ownership to the specified uid and gid. This is
     especially problematic when recursively chown(2)ing a large set of
     files which is commong with the aforementioned portable home
     directory and container and vm scenario.

   - Idmapped mounts allow to change ownership locally, restricting it
     to specific mounts, and temporarily as the ownership changes only
     apply as long as the mount exists.

  Several userspace projects have either already put up patches and
  pull-requests for this feature or will do so should you decide to pull
  this:

   - systemd: In a wide variety of scenarios but especially right away
     in their implementation of portable home directories.

         https://systemd.io/HOME_DIRECTORY/

   - container runtimes: containerd, runC, LXD:To share data between
     host and unprivileged containers, unprivileged and privileged
     containers, etc. The pull request for idmapped mounts support in
     containerd, the default Kubernetes runtime is already up for quite
     a while now: https://github.com/containerd/containerd/pull/4734

   - The virtio-fs developers and several users have expressed interest
     in using this feature with virtual machines once virtio-fs is
     ported.

   - ChromeOS: Sharing host-directories with unprivileged containers.

  I've tightly synced with all those projects and all of those listed
  here have also expressed their need/desire for this feature on the
  mailing list. For more info on how people use this there's a bunch of
  talks about this too. Here's just two recent ones:

      https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf
      https://fosdem.org/2021/schedule/event/containers_idmap/

  This comes with an extensive xfstests suite covering both ext4 and
  xfs:

      https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts

  It covers truncation, creation, opening, xattrs, vfscaps, setid
  execution, setgid inheritance and more both with idmapped and
  non-idmapped mounts. It already helped to discover an unrelated xfs
  setgid inheritance bug which has since been fixed in mainline. It will
  be sent for inclusion with the xfstests project should you decide to
  merge this.

  In order to support per-mount idmappings vfsmounts are marked with
  user namespaces. The idmapping of the user namespace will be used to
  map the ids of vfs objects when they are accessed through that mount.
  By default all vfsmounts are marked with the initial user namespace.
  The initial user namespace is used to indicate that a mount is not
  idmapped. All operations behave as before and this is verified in the
  testsuite.

  Based on prior discussions we want to attach the whole user namespace
  and not just a dedicated idmapping struct. This allows us to reuse all
  the helpers that already exist for dealing with idmappings instead of
  introducing a whole new range of helpers. In addition, if we decide in
  the future that we are confident enough to enable unprivileged users
  to setup idmapped mounts the permission checking can take into account
  whether the caller is privileged in the user namespace the mount is
  currently marked with.

  The user namespace the mount will be marked with can be specified by
  passing a file descriptor refering to the user namespace as an
  argument to the new mount_setattr() syscall together with the new
  MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
  of extensibility.

  The following conditions must be met in order to create an idmapped
  mount:

   - The caller must currently have the CAP_SYS_ADMIN capability in the
     user namespace the underlying filesystem has been mounted in.

   - The underlying filesystem must support idmapped mounts.

   - The mount must not already be idmapped. This also implies that the
     idmapping of a mount cannot be altered once it has been idmapped.

   - The mount must be a detached/anonymous mount, i.e. it must have
     been created by calling open_tree() with the OPEN_TREE_CLONE flag
     and it must not already have been visible in the filesystem.

  The last two points guarantee easier semantics for userspace and the
  kernel and make the implementation significantly simpler.

  By default vfsmounts are marked with the initial user namespace and no
  behavioral or performance changes are observed.

  The manpage with a detailed description can be found here:

      1d7b902e28

  In order to support idmapped mounts, filesystems need to be changed
  and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
  patches to convert individual filesystem are not very large or
  complicated overall as can be seen from the included fat, ext4, and
  xfs ports. Patches for other filesystems are actively worked on and
  will be sent out separately. The xfstestsuite can be used to verify
  that port has been done correctly.

  The mount_setattr() syscall is motivated independent of the idmapped
  mounts patches and it's been around since July 2019. One of the most
  valuable features of the new mount api is the ability to perform
  mounts based on file descriptors only.

  Together with the lookup restrictions available in the openat2()
  RESOLVE_* flag namespace which we added in v5.6 this is the first time
  we are close to hardened and race-free (e.g. symlinks) mounting and
  path resolution.

  While userspace has started porting to the new mount api to mount
  proper filesystems and create new bind-mounts it is currently not
  possible to change mount options of an already existing bind mount in
  the new mount api since the mount_setattr() syscall is missing.

  With the addition of the mount_setattr() syscall we remove this last
  restriction and userspace can now fully port to the new mount api,
  covering every use-case the old mount api could. We also add the
  crucial ability to recursively change mount options for a whole mount
  tree, both removing and adding mount options at the same time. This
  syscall has been requested multiple times by various people and
  projects.

  There is a simple tool available at

      https://github.com/brauner/mount-idmapped

  that allows to create idmapped mounts so people can play with this
  patch series. I'll add support for the regular mount binary should you
  decide to pull this in the following weeks:

  Here's an example to a simple idmapped mount of another user's home
  directory:

	u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt

	u1001@f2-vm:/$ ls -al /home/ubuntu/
	total 28
	drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
	drwxr-xr-x 4 root   root   4096 Oct 28 04:00 ..
	-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
	-rw-r--r-- 1 ubuntu ubuntu  220 Feb 25  2020 .bash_logout
	-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25  2020 .bashrc
	-rw-r--r-- 1 ubuntu ubuntu  807 Feb 25  2020 .profile
	-rw-r--r-- 1 ubuntu ubuntu    0 Oct 16 16:11 .sudo_as_admin_successful
	-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo

	u1001@f2-vm:/$ ls -al /mnt/
	total 28
	drwxr-xr-x  2 u1001 u1001 4096 Oct 28 22:07 .
	drwxr-xr-x 29 root  root  4096 Oct 28 22:01 ..
	-rw-------  1 u1001 u1001 3154 Oct 28 22:12 .bash_history
	-rw-r--r--  1 u1001 u1001  220 Feb 25  2020 .bash_logout
	-rw-r--r--  1 u1001 u1001 3771 Feb 25  2020 .bashrc
	-rw-r--r--  1 u1001 u1001  807 Feb 25  2020 .profile
	-rw-r--r--  1 u1001 u1001    0 Oct 16 16:11 .sudo_as_admin_successful
	-rw-------  1 u1001 u1001 1144 Oct 28 00:43 .viminfo

	u1001@f2-vm:/$ touch /mnt/my-file

	u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file

	u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file

	u1001@f2-vm:/$ ls -al /mnt/my-file
	-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file

	u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
	-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file

	u1001@f2-vm:/$ getfacl /mnt/my-file
	getfacl: Removing leading '/' from absolute path names
	# file: mnt/my-file
	# owner: u1001
	# group: u1001
	user::rw-
	user:u1001:rwx
	group::rw-
	mask::rwx
	other::r--

	u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
	getfacl: Removing leading '/' from absolute path names
	# file: home/ubuntu/my-file
	# owner: ubuntu
	# group: ubuntu
	user::rw-
	user:ubuntu:rwx
	group::rw-
	mask::rwx
	other::r--"

* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
  xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
  xfs: support idmapped mounts
  ext4: support idmapped mounts
  fat: handle idmapped mounts
  tests: add mount_setattr() selftests
  fs: introduce MOUNT_ATTR_IDMAP
  fs: add mount_setattr()
  fs: add attr_flags_to_mnt_flags helper
  fs: split out functions to hold writers
  namespace: only take read lock in do_reconfigure_mnt()
  mount: make {lock,unlock}_mount_hash() static
  namespace: take lock_mount_hash() directly when changing flags
  nfs: do not export idmapped mounts
  overlayfs: do not mount on top of idmapped mounts
  ecryptfs: do not mount on top of idmapped mounts
  ima: handle idmapped mounts
  apparmor: handle idmapped mounts
  fs: make helpers idmap mount aware
  exec: handle idmapped mounts
  would_dump: handle idmapped mounts
  ...
2021-02-23 13:39:45 -08:00
Aurelien Aptel 21b200d091 cifs: report error instead of invalid when revalidating a dentry fails
Assuming
- //HOST/a is mounted on /mnt
- //HOST/b is mounted on /mnt/b

On a slow connection, running 'df' and killing it while it's
processing /mnt/b can make cifs_get_inode_info() returns -ERESTARTSYS.

This triggers the following chain of events:
=> the dentry revalidation fail
=> dentry is put and released
=> superblock associated with the dentry is put
=> /mnt/b is unmounted

This patch makes cifs_d_revalidate() return the error instead of 0
(invalid) when cifs_revalidate_dentry() fails, except for ENOENT (file
deleted) and ESTALE (file recreated).

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Suggested-by: Shyam Prasad N <nspmangalore@gmail.com>
Reviewed-by: Shyam Prasad N <nspmangalore@gmail.com>
CC: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-02-05 13:17:48 -06:00
Christian Brauner 549c729771
fs: make helpers idmap mount aware
Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:20 +01:00
Ronnie Sahlberg 3fa1c6d1b8 cifs: rename smb_vol as smb3_fs_context and move it to fs_context.h
Harmonize and change all such variables to 'ctx', where possible.
No changes to actual logic.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-13 19:12:07 -06:00
Steve French d313852d7a smb311: add support for using info level for posix extensions query
Adds calls to the newer info level for query info using SMB3.1.1 posix extensions.
The remaining two places that call the older query info (non-SMB3.1.1 POSIX)
require passing in the fid and can be updated in a later patch.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-06-12 08:54:12 -05:00
Steve French 790434ff98 smb311: Add support for lookup with posix extensions query info
Improve support for lookup when using SMB3.1.1 posix mounts.
Use new info level 100 (posix query info)

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-06-12 06:21:19 -05:00
Al Viro d9a9f4849f cifs_atomic_open(): fix double-put on late allocation failure
several iterations of ->atomic_open() calling conventions ago, we
used to need fput() if ->atomic_open() failed at some point after
successful finish_open().  Now (since 2016) it's not needed -
struct file carries enough state to make fput() work regardless
of the point in struct file lifecycle and discarding it on
failure exits in open() got unified.  Unfortunately, I'd missed
the fact that we had an instance of ->atomic_open() (cifs one)
that used to need that fput(), as well as the stale comment in
finish_open() demanding such late failure handling.  Trivially
fixed...

Fixes: fe9ec8291f "do_last(): take fput() on error after opening to out:"
Cc: stable@kernel.org # v4.7+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-12 18:25:20 -04:00
Amir Goldstein 0f060936e4 SMB3: Backup intent flag missing from some more ops
When "backup intent" is requested on the mount (e.g. backupuid or
backupgid mount options), the corresponding flag was missing from
some of the operations.

Change all operations to use the macro cifs_create_options() to
set the backup intent flag if needed.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-02-03 16:12:47 -06:00
Markus Elfring 598b6c57f2 CIFS: Return directly after a failed build_path_from_dentry() in cifs_do_create()
Return directly after a call of the function "build_path_from_dentry"
failed at the beginning.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:14:53 -06:00
Pavel Shilovsky 0b3d0ef984 CIFS: Force reval dentry if LOOKUP_REVAL flag is set
Mark inode for force revalidation if LOOKUP_REVAL flag is set.
This tells the client to actually send a QueryInfo request to
the server to obtain the latest metadata in case a directory
or a file were changed remotely. Only do that if the client
doesn't have a lease for the file to avoid unneeded round
trips to the server.

Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-10-09 00:10:50 -05:00
Ronnie Sahlberg 8de9e86c67 cifs: create a helper to find a writeable handle by path name
rename() takes a path for old_file and in SMB2 we used to just create
a compound for create(old_path)/rename/close().
If we already have a writable handle we can avoid the create() and close()
altogether and just use the existing handle.

For this situation, as we avoid doing the create()
we also avoid triggering an oplock break for the existing handle.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:37 -05:00
Ronnie Sahlberg 340625e618 cifs: replace various strncpy with strscpy and similar
Using strscpy is cleaner, and avoids some problems with
handling maximum length strings.  Linus noticed the
original problem and Aurelien pointed out some additional
problems. Fortunately most of this is SMB1 code (and
in particular the ASCII string handling older, which
is less common).

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-08-27 17:25:12 -05:00
Aurelien Aptel c847dccfbd CIFS: make mknod() an smb_version_op
This cleanup removes cifs specific code from SMB2/SMB3 code paths
which is cleaner and easier to maintain as the code to handle
special files is improved.  Below is an example creating special files
using 'sfu' mount option over SMB3 to Windows (with this patch)
(Note that to Samba server, support for saving dos attributes
has to be enabled for the SFU mount option to work).

In the future this will also make implementation of creating
special files as reparse points easier (as Windows NFS server does
for example).

   root@smf-Thinkpad-P51:~# stat -c "%F" /mnt2/char
   character special file

   root@smf-Thinkpad-P51:~# stat -c "%F" /mnt2/block
   block special file

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-03-14 19:32:36 -05:00
Paulo Alcantara c988de29ca cifs: Fix separator when building path from dentry
Make sure to use the CIFS_DIR_SEP(cifs_sb) as path separator for
prefixpath too. Fixes a bug with smb1 UNIX extensions.

Fixes: a6b5058faf ("fs/cifs: make share unaccessible at root level mountable")
Signed-off-by: Paulo Alcantara <palcantara@suse.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
2018-12-06 02:20:17 -06:00
Al Viro 44907d7900 get rid of 'opened' argument of ->atomic_open() - part 3
now it can be done...

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12 10:04:20 -04:00
Al Viro be12af3ef5 getting rid of 'opened' argument of ->atomic_open() - part 1
'opened' argument of finish_open() is unused.  Kill it.

Signed-off-by Al Viro <viro@zeniv.linux.org.uk>
2018-07-12 10:04:19 -04:00
Al Viro 73a09dd943 introduce FMODE_CREATED and switch to it
Parallel to FILE_CREATED, goes into ->f_mode instead of *opened.
NFS is a bit of a wart here - it doesn't have file at the point
where FILE_CREATED used to be set, so we need to propagate it
there (for now).  IMA is another one (here and everywhere)...

Note that this needs do_dentry_open() to leave old bits in ->f_mode
alone - we want it to preserve FMODE_CREATED if it had been already
set (no other bit can be there).

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12 10:04:18 -04:00
Linus Torvalds 325520142b some smb3 fixes for stable, as well as addition of ftrace hooks for cifs.ko, and improvements in compounding and smbdirect (RDMA)
-----BEGIN PGP SIGNATURE-----
 
 iQHHBAABCgAxFiEE6fsu8pdIjtWE/DpLiiy9cAdyT1EFAlsUs3QTHHNtZnJlbmNo
 QGdtYWlsLmNvbQAKCRCKLL1wB3JPUWFIDACpB/nxQT0l+SMfXe+7W5Txy6x1hasi
 fFtcQd03dSzTwGN6ANPmsszktu5LVU1htifwSDIMj9x6MLE+VRCFhuWEszs6N/WD
 kQO3DQmuyB3w+s8rkN2V+mjamDuf0jTiq2uLsTvicUsyEmJtJgKJdcmB+bDxXTcE
 AQbh5qjMtQIl4IyI6cqxIRm/6laeVyGurJKYGp2G8UcyLg6ddv/vp5mXDIdoCnrv
 /gvzi/A7a7UwTEZolFa2vNT/KTLofG8fstdtfqlSa9qTWZwjhoFPKVd3eQPJV3Fj
 SjTpwbnM4q0MSY7XijPMkSpnBniaF3e5bf3Cp6QmtQeU+FmfkoYOy7EUlZJ1ar15
 xNjLEl/EEfy1C3hIwsdoVB8iLFPhFlAMONUWGjs2cyiTRMZx2OP4VgbyN8pcZUcJ
 mGNbBx2SQDJo8iR579dRh2gl6Gy/i5DNOClyIPfEpzGTURrzoV0C9EAnoweyK1qh
 wxvdA7SfPRi2rw9a4Kg+PJxWnd8oNRyhzUw=
 =EXH7
 -----END PGP SIGNATURE-----

Merge tag '4.18-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs updates from Steve French:

 - smb3 fixes for stable

 - addition of ftrace hooks for cifs.ko

 - improvements in compounding and smbdirect (rdma)

* tag '4.18-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: (38 commits)
  CIFS: Add support for direct pages in wdata
  CIFS: Use offset when reading pages
  CIFS: Add support for direct pages in rdata
  cifs: update multiplex loop to handle compounded responses
  cifs: remove header_preamble_size where it is always 0
  cifs: remove struct smb2_hdr
  CIFS: 511c54a2f6 adds a check for session expiry, status STATUS_NETWORK_SESSION_EXPIRED, however the server can also respond with STATUS_USER_SESSION_DELETED in cases where the session has been idle for some time and the server reaps the session to recover resources.
  cifs: change smb2_get_data_area_len to take a smb2_sync_hdr as argument
  cifs: update smb2_calc_size to use smb2_sync_hdr instead of smb2_hdr
  cifs: remove struct smb2_oplock_break_rsp
  cifs: remove rfc1002 header from all SMB2 response structures
  smb3: on reconnect set PreviousSessionId field
  smb3: Add posix create context for smb3.11 posix mounts
  smb3: add tracepoints for smb2/smb3 open
  cifs: add debug output to show nocase mount option
  smb3: add define for id for posix create context and corresponding struct
  cifs: update smb2_check_message to handle PDUs without a 4 byte length header
  smb3: allow "posix" mount option to enable new SMB311 protocol extensions
  smb3: add support for posix negotiate context
  cifs: allow disabling less secure legacy dialects
  ...
2018-06-04 14:42:46 -07:00
Linus Torvalds b058efc1ac Merge branch 'work.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull dcache lookup cleanups from Al Viro:
 "Cleaning ->lookup() instances up - mostly d_splice_alias() conversions"

* 'work.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (29 commits)
  switch the rest of procfs lookups to d_splice_alias()
  procfs: switch instantiate_t to d_splice_alias()
  don't bother with tid_fd_revalidate() in lookups
  proc_lookupfd_common(): don't bother with instantiate unless the file is open
  procfs: get rid of ancient BS in pid_revalidate() uses
  cifs_lookup(): switch to d_splice_alias()
  cifs_lookup(): cifs_get_inode_...() never returns 0 with *inode left NULL
  9p: unify paths in v9fs_vfs_lookup()
  ncp_lookup(): use d_splice_alias()
  hfsplus: switch to d_splice_alias()
  hfs: don't allow mounting over .../rsrc
  hfs: use d_splice_alias()
  omfs_lookup(): report IO errors, use d_splice_alias()
  orangefs_lookup: simplify
  openpromfs: switch to d_splice_alias()
  xfs_vn_lookup: simplify a bit
  adfs_lookup: do not fail with ENOENT on negatives, use d_splice_alias()
  adfs_lookup_byname: .. *is* taken care of in fs/namei.c
  romfs_lookup: switch to d_splice_alias()
  qnx6_lookup: switch to d_splice_alias()
  ...
2018-06-04 13:46:22 -07:00
Steve French ce558b0e17 smb3: Add posix create context for smb3.11 posix mounts
Signed-off-by: Steve French <smfrench@gmail.com>
2018-05-31 21:23:07 -05:00
Al Viro 11f17c9bd7 cifs_lookup(): switch to d_splice_alias()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-22 14:28:03 -04:00
Al Viro a8b75f663e cifs_lookup(): cifs_get_inode_...() never returns 0 with *inode left NULL
not since 2004...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-22 14:28:02 -04:00
Steve French 1d0cffa674 cifs: do not allow creating sockets except with SMB1 posix exensions
RHBZ: 1453123

Since at least the 3.10 kernel and likely a lot earlier we have
not been able to create unix domain sockets in a cifs share
when mounted using the SFU mount option (except when mounted
with the cifs unix extensions to Samba e.g.)
Trying to create a socket, for example using the af_unix command from
xfstests will cause :
BUG: unable to handle kernel NULL pointer dereference at 00000000
00000040

Since no one uses or depends on being able to create unix domains sockets
on a cifs share the easiest fix to stop this vulnerability is to simply
not allow creation of any other special files than char or block devices
when sfu is used.

Added update to Ronnie's patch to handle a tcon link leak, and
to address a buf leak noticed by Gustavo and Colin.

Acked-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
CC:  Colin Ian King <colin.king@canonical.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reported-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Cc: stable@vger.kernel.org
2018-04-20 13:31:32 -05:00
Ronnie Sahlberg f74bc7c667 cifs: check MaxPathNameComponentLength != 0 before using it
And fix tcon leak in error path.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: David Disseldorp <ddiss@samba.org>
2017-10-30 02:11:38 -05:00
Steve French 6e3c1529c3 CIFS: remove endian related sparse warning
Recent patch had an endian warning ie
cifs: return ENAMETOOLONG for overlong names in cifs_open()/cifs_lookup()

Signed-off-by: Steve French <smfrench@gmail.com>
CC: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
2017-08-30 14:43:11 -05:00
Ronnie Sahlberg d3edede29f cifs: return ENAMETOOLONG for overlong names in cifs_open()/cifs_lookup()
Add checking for the path component length and verify it is <= the maximum
that the server advertizes via FileFsAttributeInformation.

With this patch cifs.ko will now return ENAMETOOLONG instead of ENOENT
when users to access an overlong path.

To test this, try to cd into a (non-existing) directory on a CIFS share
that has a too long name:
cd /mnt/aaaaaaaaaaaaaaa...

and it now should show a good error message from the shell:
bash: cd: /mnt/aaaaaaaaaaaaaaaa...aaaaaa: File name too long

rh bz 1153996

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Cc: <stable@vger.kernel.org>
2017-08-23 13:34:52 -05:00
Aurelien Aptel 268a635d41 CIFS: add build_path_from_dentry_optional_prefix()
this function does the same thing as add build_path_from_dentry() but
takes a boolean parameter to decide whether or not to prefix the path
with the tree name.

we cannot rely on tcon->Flags & SMB_SHARE_IS_IN_DFS for SMB2 as smb2
code never sets tcon->Flags but it sets tcon->share_flags and it seems
the SMB_SHARE_IS_IN_DFS has different semantics in SMB2: the prefix
shouldn't be added everytime it was in SMB1.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2017-03-01 22:26:10 -06:00
Sachin Prabhu 374402a2a1 cifs_get_root shouldn't use path with tree name
When a server returns the optional flag SMB_SHARE_IS_IN_DFS in response
to a tree connect, cifs_build_path_to_root() will return a pathname
which includes the hostname. This causes problems with cifs_get_root()
which separates each component and does a lookup for each component of
the path which in this case will incorrectly include looking up the
hostname component as a path component.

We encountered a problem with dfs shares hosted by a Netapp. When
connecting to nodes pointed to by the DFS share. The tree connect for
these nodes return SMB_SHARE_IS_IN_DFS resulting failures in lookup
in cifs_get_root().

RH bz: 1373153
The patch was tested against a Netapp simulator and by a user using an
actual Netapp server.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reported-by: Pierguido Lambri <plambri@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2016-12-15 01:42:54 -06:00
Miklos Szeredi a00be0e31f cifs: don't use ->d_time
Use d_fsdata instead, which is the same size.  Introduce helpers to hide
the typecasts.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: Steve French <sfrench@samba.org>
2016-09-16 12:44:21 +02:00
Al Viro 6fa67e7075 get rid of 'parent' argument of ->d_compare()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-31 16:37:25 -04:00
Al Viro d3fe19852e cifs, msdos, vfat, hfs+: don't bother with parent in ->d_compare()
dentry->d_sb is just as good as parent->d_sb

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-29 18:27:51 -04:00
Linus Torvalds b0c4e2acdd Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6
Pull CIFS/SMB3 fixes from Steve French:
 "Various CIFS/SMB3 fixes, most for stable"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: Fix a possible invalid memory access in smb2_query_symlink()
  fs/cifs: make share unaccessible at root level mountable
  cifs: fix crash due to race in hmac(md5) handling
  cifs: unbreak TCP session reuse
  cifs: Check for existing directory when opening file with O_CREAT
  Add MF-Symlinks support for SMB 2.0
2016-07-29 11:29:13 -07:00
Linus Torvalds 554828ee0d Merge branch 'salted-string-hash'
This changes the vfs dentry hashing to mix in the parent pointer at the
_beginning_ of the hash, rather than at the end.

That actually improves both the hash and the code generation, because we
can move more of the computation to the "static" part of the dcache
setup, and do less at lookup runtime.

It turns out that a lot of other hash users also really wanted to mix in
a base pointer as a 'salt' for the hash, and so the slightly extended
interface ends up working well for other cases too.

Users that want a string hash that is purely about the string pass in a
'salt' pointer of NULL.

* merge branch 'salted-string-hash':
  fs/dcache.c: Save one 32-bit multiply in dcache lookup
  vfs: make the string hashes salt the hash
2016-07-28 12:26:31 -07:00
Aurelien Aptel a6b5058faf fs/cifs: make share unaccessible at root level mountable
if, when mounting //HOST/share/sub/dir/foo we can query /sub/dir/foo but
not any of the path components above:

- store the /sub/dir/foo prefix in the cifs super_block info
- in the superblock, set root dentry to the subpath dentry (instead of
  the share root)
- set a flag in the superblock to remember it
- use prefixpath when building path from a dentry

fixes bso#8950

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2016-07-27 22:50:55 -05:00
Sachin Prabhu 8d9535b6ef cifs: Check for existing directory when opening file with O_CREAT
When opening a file with O_CREAT flag, check to see if the file opened
is an existing directory.

This prevents the directory from being opened which subsequently causes
a crash when the close function for directories cifs_closedir() is called
which frees up the file->private_data memory while the file is still
listed on the open file list for the tcon.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reported-by: Xiaoli Feng <xifeng@redhat.com>
2016-07-12 16:09:38 -05:00
Al Viro 00699ad857 Use the right predicate in ->atomic_open() instances
->atomic_open() can be given an in-lookup dentry *or* a negative one
found in dcache.  Use d_in_lookup() to tell one from another, rather
than d_unhashed().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-05 16:02:23 -04:00
Linus Torvalds 8387ff2577 vfs: make the string hashes salt the hash
We always mixed in the parent pointer into the dentry name hash, but we
did it late at lookup time.  It turns out that we can simplify that
lookup-time action by salting the hash with the parent pointer early
instead of late.

A few other users of our string hashes also wanted to mix in their own
pointers into the hash, and those are updated to use the same mechanism.

Hash users that don't have any particular initial salt can just use the
NULL pointer as a no-salt.

Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-10 20:21:46 -07:00
Nakajima Akira bc8ebdc4f5 Fix that several functions handle incorrect value of mapchars
Cifs client has problem with reserved chars filename.

[BUG1] : several functions handle incorrect value of mapchars
-	cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
+	cifs_remap(cifs_sb));

[BUG2] : forget to convert reserved chars when creating SymbolicLink.
-	CIFSUnixCreateSymLink() calls cifs_strtoUTF16
+	CIFSUnixCreateSymLink() calls cifsConvertToUTF16() with remap

[BUG3] : forget to convert reserved chars when getting SymbolicLink.
-	CIFSSMBUnixQuerySymLink() calls cifs_strtoUTF16
+	CIFSSMBUnixQuerySymLink() calls cifsConvertToUTF16() with remap

[BUG4] : /proc/mounts don't show "mapposix" when using mapposix mount option
+	    cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
+ 		seq_puts(s, ",mapposix");

Reported-by: t.wede@kw-reneg.de
Reported-by: Nakajima Akira <nakajima.akira@nttcom.co.jp>
Signed-off-by: Nakajima Akira <nakajima.akira@nttcom.co.jp>
Signed-off-by: Carl Schaefer <schaefer@trilug.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2015-05-10 19:56:35 -05:00
David Howells 2b0143b5c9 VFS: normal filesystems (and lustre): d_inode() annotations
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:57 -04:00
Steve French db8b631d4b Allow mknod and mkfifo on SMB2/SMB3 mounts
The "sfu" mount option did not work on SMB2/SMB3 mounts.
With these changes when the "sfu" mount option is passed in
on an smb2/smb2.1/smb3 mount the client can emulate (and
recognize) fifo and device (character and device files).

In addition the "sfu" mount option should not conflict
with "mfsymlinks" (symlink emulation) as we will never
create "sfu" style symlinks, but using "sfu" mount option
will allow us to recognize existing symlinks, created with
Microsoft "Services for Unix" (SFU and SUA).

To enable the "sfu" mount option for SMB2/SMB3 the calling
syntax of the generic cifs/smb2/smb3 sync_read and sync_write
protocol dependent function needed to be changed (we
don't have a file struct in all cases), but this actually
ended up simplifying the code a little.

Signed-off-by: Steve French <smfrench@gmail.com>
2014-10-16 15:20:19 -05:00
Al Viro 35c265e008 cifs: switch to use of %p[dD]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-09 02:39:03 -04:00
Namjae Jeon 787aded650 cifs: Allow directIO read/write during cache=strict
Currently cifs have all or nothing approach for directIO operations.
cache=strict mode does not allow directIO while cache=none mode performs
all the operations as directIO even when user does not specify O_DIRECT
flag. This patch enables strict cache mode to honour directIO semantics.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-08-22 00:20:39 -05:00
Steve French 42eacf9e57 [CIFS] Fix cifsacl mounts over smb2 to not call cifs
When mounting with smb2/smb3 (e.g. vers=2.1) and cifsacl mount option,
it was trying to get the mode by querying the acl over the cifs
rather than smb2 protocol.  This patch makes that protocol
independent and makes cifsacl smb2 mounts return a more intuitive
operation not supported error (until we add a worker function
for smb2_get_acl).

Note that a previous patch fixed getxattr/setxattr for the CIFSACL xattr
which would unconditionally call cifs_get_acl and cifs_set_acl (even when
mounted smb2). I made those protocol independent last week (new protocol
version operations "get_acl" and "set_acl" but did not add an
smb2_get_acl and smb2_set_acl yet so those now simply return EOPNOTSUPP
which at least is better than sending cifs requests on smb2 mount)

The previous patches did not fix the one remaining case though ie
mounting with "cifsacl" when getting mode from acl would unconditionally
end up calling "cifs_get_acl_from_fid" even for smb2 - so made that protocol
independent but to make that protocol independent had to make sure that the callers
were passing the protocol independent handle structure (cifs_fid) instead
of cifs specific _u16 network file handle (ie cifs_fid instead of cifs_fid->fid)

Now mount with smb2 and cifsacl mount options will return EOPNOTSUP (instead
of timing out) and a future patch will add smb2 operations (e.g. get_smb2_acl)
to enable this.

Signed-off-by: Steve French <smfrench@gmail.com>
2014-02-10 14:08:16 -06:00
Pavel Shilovsky d81b8a40e2 CIFS: Cleanup cifs open codepath
Rename CIFSSMBOpen to CIFS_open and make it take
cifs_open_parms structure as a parm.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-01-20 09:52:13 -06:00
Pavel Shilovsky dd12067156 CIFS: Cleanup cifs_mknod
Rename camel case variable and fix comment style.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-01-20 09:52:05 -06:00
Shirish Pargaonkar f1e3268126 cifs: set FILE_CREATED
Set FILE_CREATED on O_CREAT|O_EXCL.

cifs code didn't change during commit 116cc02253

Kernel bugzilla 66251

Signed-off-by: Shirish Pargaonkar <spargaonkar@suse.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
CC: Stable <stable@kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-12-27 15:14:45 -06:00
Jeff Layton a8582159ed cifs: don't spam the logs on unexpected lookup errors
Andrey reported that he was seeing cifs.ko spam the logs with messages
like this:

    CIFS VFS: Unexpected lookup error -26

He was listing the root directory of a server and hitting an error when
trying to QUERY_PATH_INFO against hiberfil.sys and pagefile.sys. The
right fix would be to switch the lookup code over to using FIND_FIRST,
but until then we really don't need to report this at a level of
KERN_ERR. Convert this message over to FYI level.

Reported-by: "Andrey Shernyukov" <andreysh@nioch.nsc.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-11-11 16:34:53 -06:00
Miklos Szeredi dfb1d61b0e cifs: fix filp leak in cifs_atomic_open()
If an error occurs after having called finish_open() then fput() needs to
be called on the already opened file.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Steve French <sfrench@samba.org>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-16 19:17:24 -04:00
Jeff Layton ec71e0e159 cifs: convert case-insensitive dentry ops to use new case conversion routines
Have the case-insensitive d_compare and d_hash routines convert each
character in the filenames to wchar_t's and then use the new
cifs_toupper routine to convert those into uppercase.

With this scheme we should more closely emulate the case conversion that
the servers will do.

Reported-and-Tested-by: Jan-Marek Glogowski <glogow@fbihome.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-08 14:38:08 -05:00
Pavel Shilovsky 9cbc0b7339 CIFS: Reconnect durable handles for SMB2
On reconnects, we need to reopen file and then obtain all byte-range
locks held by the client. SMB2 protocol provides feature to make
this process atomic by reconnecting to the same file handle
with all it's byte-range locks. This patch adds this capability
for SMB2 shares.

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steven French <steven@steven-GA-970A-DS3.(none)>
2013-07-10 13:08:40 -05:00