Commit Graph

18 Commits

Author SHA1 Message Date
Christian Brauner
4472071331
fs: use low-level mapping helpers
In a few places the vfs needs to interact with bare k{g,u}ids directly
instead of struct inode. These are just a few. In previous patches we
introduced low-level mapping helpers that are able to support
filesystems mounted an idmapping. This patch simply converts the places
to use these new helpers.

Link: https://lore.kernel.org/r/20211123114227.3124056-7-brauner@kernel.org (v1)
Link: https://lore.kernel.org/r/20211130121032.3753852-7-brauner@kernel.org (v2)
Link: https://lore.kernel.org/r/20211203111707.3901969-7-brauner@kernel.org
Cc: Seth Forshee <sforshee@digitalocean.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
CC: linux-fsdevel@vger.kernel.org
Reviewed-by: Seth Forshee <sforshee@digitalocean.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-12-03 18:58:11 +01:00
Christian Brauner
a793d79ea3
fs: move mapping helpers
The low-level mapping helpers were so far crammed into fs.h. They are
out of place there. The fs.h header should just contain the higher-level
mapping helpers that interact directly with vfs objects such as struct
super_block or struct inode and not the bare mapping helpers. Similarly,
only vfs and specific fs code shall interact with low-level mapping
helpers. And so they won't be made accessible automatically through
regular {g,u}id helpers.

Link: https://lore.kernel.org/r/20211123114227.3124056-3-brauner@kernel.org (v1)
Link: https://lore.kernel.org/r/20211130121032.3753852-3-brauner@kernel.org (v2)
Link: https://lore.kernel.org/r/20211203111707.3901969-3-brauner@kernel.org
Cc: Seth Forshee <sforshee@digitalocean.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
CC: linux-fsdevel@vger.kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Seth Forshee <sforshee@digitalocean.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-12-03 18:50:17 +01:00
Hyunchul Lee
8f77150c15 ksmbd: add buffer validation for SMB2_CREATE_CONTEXT
Add buffer validation for SMB2_CREATE_CONTEXT.

Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Reviewed-by: Ralph Boehme <slow@samba.org>
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-30 09:58:07 -05:00
Namjae Jeon
4cf0ccd033 ksmbd: fix control flow issues in sid_to_id()
Addresses-Coverity reported Control flow issues in sid_to_id()
/fs/ksmbd/smbacl.c: 277 in sid_to_id()
271
272	if (sidtype == SIDOWNER) {
273		kuid_t uid;
274		uid_t id;
275
276		id = le32_to_cpu(psid->sub_auth[psid->num_subauth - 1]);
>>>	CID 1506810:  Control flow issues  (NO_EFFECT)
>>>	This greater-than-or-equal-to-zero comparison of an unsigned value
>>>	is always true. "id >= 0U".
277		if (id >= 0) {
278			/*
279			 * Translate raw sid into kuid in the server's user
280			 * namespace.
281			 */
282			uid = make_kuid(&init_user_ns, id);

Addresses-Coverity: ("Control flow issues")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-08 17:16:13 -05:00
Christian Brauner
28a5d3de9d ksmbd: defer notify_change() call
When ownership is changed we might in certain scenarios loose the
ability to alter the inode after we changed ownership. This can e.g.
happen when we are on an idmapped mount where uid 0 is mapped to uid
1000 and uid 1000 is mapped to uid 0.
A caller with fs*id 1000 will be able to create files as *id 1000 on
disk. They will also be able to change ownership of files owned by *id 0
to *id 1000 but they won't be able to change ownership in the other
direction. This means acl operations following notify_change() would
fail. Move the notify_change() call after the acls have been updated.
This guarantees that we don't end up with spurious "hash value diff"
warnings later on because we managed to change ownership but didn't
manage to alter acls.

Cc: Steve French <stfrench@microsoft.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Hyunchul Lee <hyc.lee@gmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03 23:29:45 -05:00
Christian Brauner
55cd04d75e ksmbd: fix translation in sid_to_id()
The sid_to_id() functions is relevant when changing ownership of
filesystem objects based on acl information. In this case we need to
first translate the relevant s*ids into k*ids in ksmbd's user namespace
and account for any idmapped mounts. Requesting a change in ownership
requires the inverse translation to be applied when we would report
ownership to userspace. So k*id_from_mnt() must be used here.

Cc: Steve French <stfrench@microsoft.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Hyunchul Lee <hyc.lee@gmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03 23:29:45 -05:00
Christian Brauner
f0bb29d5c6 ksmbd: fix subauth 0 handling in sid_to_id()
It's not obvious why subauth 0 would be excluded from translation. This
would lead to wrong results whenever a non-identity idmapping is used.

Cc: Steve French <stfrench@microsoft.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Hyunchul Lee <hyc.lee@gmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03 23:29:44 -05:00
Christian Brauner
0e844efebd ksmbd: fix translation in acl entries
The ksmbd server performs translation of posix acls to smb acls.
Currently the translation is wrong since the idmapping of the mount is
used to map the ids into raw userspace ids but what is relevant is the
user namespace of ksmbd itself. The user namespace of ksmbd itself which
is the initial user namespace. The operation is similar to asking "What
*ids would a userspace process see given that k*id in the relevant user
namespace?". Before the final translation we need to apply the idmapping
of the mount in case any is used. Add two simple helpers for ksmbd.

Cc: Steve French <stfrench@microsoft.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Hyunchul Lee <hyc.lee@gmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03 23:29:44 -05:00
Christian Brauner
43205ca719 ksmbd: fix translation in ksmbd_acls_fattr()
When creating new filesystem objects ksmbd translates between k*ids and
s*ids. For this it often uses struct smb_fattr and stashes the k*ids in
cf_uid and cf_gid. Let cf_uid and cf_gid always contain the final
information taking any potential idmapped mounts into account. When
finally translation cf_*id into s*ids translate them into the user
namespace of ksmbd since that is the relevant user namespace here.

Cc: Steve French <stfrench@microsoft.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Hyunchul Lee <hyc.lee@gmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03 23:29:44 -05:00
Namjae Jeon
e70e392fa7 ksmbd: fix permission check issue on chown and chmod
When commanding chmod and chown on cifs&ksmbd, ksmbd allows it without file
permissions check. There is code to check it in settattr_prepare.
Instead of setting the inode directly, update the mode and uid/gid
through notify_change.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-08-21 23:26:34 +09:00
Namjae Jeon
a9a27d4ab3 ksmbd: don't set FILE DELETE and FILE_DELETE_CHILD in access mask by default
When there is no dacl in request, ksmbd send dacl that coverted by using
file permission. This patch don't set FILE DELETE and FILE_DELETE_CHILD
in access mask by default.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-08-20 15:45:44 +09:00
Namjae Jeon
777cad1604 ksmbd: remove select FS_POSIX_ACL in Kconfig
ksmbd is forcing to turn on FS_POSIX_ACL in Kconfig to use vfs acl
functions(posix_acl_alloc, get_acl, set_posix_acl). OpenWRT and other
platform doesn't use acl and this config is disable by default in
kernel. This patch use IS_ENABLED() to know acl config is enable and use
acl function if it is enable.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-08-13 08:18:10 +09:00
Namjae Jeon
a9071e3c86 ksmbd: fix memory leak in smb_inherit_dacl()
Add two labels to fix memory leak in smb_inherit_dacl().

Reported-by: Coverity Scan <scan-admin@coverity.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-08 15:46:16 +09:00
Hyunchul Lee
465d720485 ksmbd: call mnt_user_ns once in a function
Avoid calling mnt_user_ns() many time in
a function.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Christian Brauner <christian@brauner.io>
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-05 09:22:49 +09:00
Hyunchul Lee
af34983e83 ksmbd: add user namespace support
For user namespace support, call vfs functions
with struct user_namespace got from struct path.

This patch have been tested mannually as below.

Create an id-mapped mount using the mount-idmapped utility
(https://github.com/brauner/mount-idmapped).
$ mount-idmapped --map-mount b:1003:1002:1 /home/foo <EXPORT DIR>/foo
(the user, "foo" is 1003, and the user "bar" is 1002).

And  mount the export directory using cifs with the user, "bar".
succeed to create/delete/stat/read/write files and directory in
the <EXPORT DIR>/foo. But fail with a bind mount for /home/foo.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-02 16:27:10 +09:00
Hyunchul Lee
ef24c962d0 ksmbd: replace struct dentry with struct path in some function's arguments
For user namespace support, we need to pass
struct user_namespace with struct dentry
to some functions. For reducing the number
of arguments, replace the struct dentry with
struct path in these functions.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-02 16:27:08 +09:00
Namjae Jeon
8b758859df ksmbd: reorder and document on-disk and netlink structures in headers
Reorder and document on-disk and netlink structures in headers.

This is a userspace ABI to communicate data between ksmbd and user IPC
daemon using netlink. This is added to track and cache user account DB
and share configuration info from userspace.

 - KSMBD_EVENT_HEARTBEAT_REQUEST(ksmbd_heartbeat)
   This event is to check whether user IPC daemon is alive. If user IPC
   daemon is dead, ksmbd keep existing connection till disconnecting and
   new connection will be denied.

 - KSMBD_EVENT_STARTING_UP(ksmbd_startup_request)
   This event is to receive the information that initializes the ksmbd
   server from the user IPC daemon and to start the server. The global
   section parameters are given from smb.conf as initialization
   information.

 - KSMBD_EVENT_SHUTTING_DOWN(ksmbd_shutdown_request)
   This event is to shutdown ksmbd server.

 - KSMBD_EVENT_LOGIN_REQUEST/RESPONSE(ksmbd_login_request/response)
   This event is to get user account info to user IPC daemon.

 - KSMBD_EVENT_SHARE_CONFIG_REQUEST/RESPONSE
   (ksmbd_share_config_request/response)
   This event is to get net share configuration info.

 - KSMBD_EVENT_TREE_CONNECT_REQUEST/RESPONSE
   (ksmbd_tree_connect_request/response)
   This event is to get session and tree connect info.

 - KSMBD_EVENT_TREE_DISCONNECT_REQUEST(ksmbd_tree_disconnect_request)
   This event is to send tree disconnect info to user IPC daemon.

 - KSMBD_EVENT_LOGOUT_REQUEST(ksmbd_logout_request)
   This event is to send logout request to user IPC daemon.

 - KSMBD_EVENT_RPC_REQUEST/RESPONSE(ksmbd_rpc_command)
   This event is to make DCE/RPC request like srvsvc, wkssvc, lsarpc,
   samr to be processed in userspace.

 - KSMBD_EVENT_SPNEGO_AUTHEN_REQUEST/RESPONSE
   (ksmbd_spnego_authen_request/response)
   This event is to make kerberos authentication to be processed in
   userspace.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-30 14:47:24 +09:00
Namjae Jeon
1a93084b9a ksmbd: move fs/cifsd to fs/ksmbd
Move fs/cifsd to fs/ksmbd and rename the remaining cifsd name to ksmbd.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-28 16:28:31 +09:00