A use-after-free is possible if one thread destroys the file
via __ksmbd_close_fd while another thread holds a reference to
it. The existing checks on fp->refcount are not sufficient to
prevent this.
The fix takes ft->lock around the section which removes the
file from the file table. This prevents two threads acquiring the
same file pointer via __close_file_table_ids, as well as the other
functions which retrieve a file from the IDR and which already use
this same lock.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Heelan <seanheelan@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
ksmbd_vfs_stream_write() did not validate whether the write offset
(*pos) was within the bounds of the existing stream data length (v_len).
If *pos was greater than or equal to v_len, this could lead to an
out-of-bounds memory write.
This patch adds a check to ensure *pos is less than v_len before
proceeding. If the condition fails, -EINVAL is returned.
Cc: stable@vger.kernel.org
Signed-off-by: Norbert Szetei <norbert@doyensec.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
The previous patch that added bounds check for create lease context
introduced a memory leak. When the bounds check fails, the function
returns NULL without freeing the previously allocated lease_ctx_info
structure.
This patch fixes the issue by adding kfree(lreq) before returning NULL
in both boundary check cases.
Fixes: bab703ed84 ("ksmbd: add bounds check for create lease context")
Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Client can send empty newname string to ksmbd server.
It will cause a kernel oops from d_alloc.
This patch return the error when attempting to rename
a file or directory with an empty new name string.
Cc: stable@vger.kernel.org
Reported-by: Norbert Szetei <norbert@doyensec.com>
Tested-by: Norbert Szetei <norbert@doyensec.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
The sess->user object can currently be in use by another thread, for
example if another connection has sent a session setup request to
bind to the session being free'd. The handler for that connection could
be in the smb2_sess_setup function which makes use of sess->user.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Heelan <seanheelan@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Setting sess->user = NULL was introduced to fix the dangling pointer
created by ksmbd_free_user. However, it is possible another thread could
be operating on the session and make use of sess->user after it has been
passed to ksmbd_free_user but before sess->user is set to NULL.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Heelan <seanheelan@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
The user can set any value for 'deadtime'. This affects the arithmetic
expression 'req->deadtime * SMB_ECHO_INTERVAL', which is subject to
overflow. The added check makes the server behavior more predictable.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 0626e6641f ("cifsd: add server handler for central processing and tranport layers")
Cc: stable@vger.kernel.org
Signed-off-by: Denis Arefev <arefev@swemel.ru>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Move tcp_transport free to ksmbd_conn_free. If ksmbd connection is
referenced when ksmbd server thread terminates, It will not be freed,
but conn->tcp_transport is freed. __smb2_lease_break_noti can be performed
asynchronously when the connection is disconnected. __smb2_lease_break_noti
calls ksmbd_conn_write, which can cause use-after-free
when conn->ksmbd_transport is already freed.
Cc: stable@vger.kernel.org
Reported-by: Norbert Szetei <norbert@doyensec.com>
Tested-by: Norbert Szetei <norbert@doyensec.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
wait_event_timeout() will set the state of the current
task to TASK_UNINTERRUPTIBLE, before doing the condition check. This
means that ksmbd_durable_scavenger_alive() will try to acquire the mutex
while already in a sleeping state. The scheduler warns us by giving
the following warning:
do not call blocking ops when !TASK_RUNNING; state=2 set at
[<0000000061515a6f>] prepare_to_wait_event+0x9f/0x6c0
WARNING: CPU: 2 PID: 4147 at kernel/sched/core.c:10099 __might_sleep+0x12f/0x160
mutex lock is not needed in ksmbd_durable_scavenger_alive().
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
krb_authenticate frees sess->user and does not set the pointer
to NULL. It calls ksmbd_krb5_authenticate to reinitialise
sess->user but that function may return without doing so. If
that happens then smb2_sess_setup, which calls krb_authenticate,
will be accessing free'd memory when it later uses sess->user.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Heelan <seanheelan@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Two new file system attributes were recently added. See MS-FSCC 2.5.1:
FILE_SUPPORTS_POSIX_UNLINK_RENAME and
FILE_RETURNS_CLEANUP_RESULT_INFO
Update the missing defines for ksmbd and cifs.ko
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
The Client send malformed smb2 negotiate request. ksmbd return error
response. Subsequently, the client can send smb2 session setup even
thought conn->preauth_info is not allocated.
This patch add KSMBD_SESS_NEED_SETUP status of connection to ignore
session setup request if smb2 negotiate phase is not complete.
Cc: stable@vger.kernel.org
Tested-by: Steve French <stfrench@microsoft.com>
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-26505
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Access psid->sub_auth[psid->num_subauth - 1] without checking
if num_subauth is non-zero leads to an out-of-bounds read.
This patch adds a validation step to ensure num_subauth != 0
before sub_auth is accessed.
Cc: stable@vger.kernel.org
Signed-off-by: Norbert Szetei <norbert@doyensec.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
The dacloffset field was originally typed as int and used in an
unchecked addition, which could overflow and bypass the existing
bounds check in both smb_check_perm_dacl() and smb_inherit_dacl().
This could result in out-of-bounds memory access and a kernel crash
when dereferencing the DACL pointer.
This patch converts dacloffset to unsigned int and uses
check_add_overflow() to validate access to the DACL.
Cc: stable@vger.kernel.org
Signed-off-by: Norbert Szetei <norbert@doyensec.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
There is a race condition between session setup and
ksmbd_sessions_deregister. The session can be freed before the connection
is added to channel list of session.
This patch check reference count of session before freeing it.
Cc: stable@vger.kernel.org
Reported-by: Sean Heelan <seanheelan@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Pull smb server updates from Steve French:
- Two fixes for bounds checks of open contexts
- Two multichannel fixes, including one for important UAF
- Oplock/lease break fix for potential ksmbd connection refcount leak
- Security fix to free crypto data more securely
- Fix to enable allowing Kerberos authentication by default
- Two RDMA/smbdirect fixes
- Minor cleanup
* tag 'v6.15rc-part1-ksmbd-server-fixes' of git://git.samba.org/ksmbd:
ksmbd: fix r_count dec/increment mismatch
ksmbd: fix multichannel connection failure
ksmbd: fix use-after-free in ksmbd_sessions_deregister()
ksmbd: use ib_device_get_netdev() instead of calling ops.get_netdev
ksmbd: use aead_request_free to match aead_request_alloc
Revert "ksmbd: fix missing RDMA-capable flag for IPoIB device in ksmbd_rdma_capable_netdev()"
ksmbd: add bounds check for create lease context
ksmbd: add bounds check for durable handle context
ksmbd: make SMB_SERVER_KERBEROS5 enable by default
ksmbd: Use str_read_write() and str_true_false() helpers
r_count is only increased when there is an oplock break wait,
so r_count inc/decrement are not paired. This can cause r_count
to become negative, which can lead to a problem where the ksmbd
thread does not terminate.
Fixes: 3aa660c059 ("ksmbd: prevent connection release during oplock break notification")
Reported-by: Norbert Szetei <norbert@doyensec.com>
Tested-by: Norbert Szetei <norbert@doyensec.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
ksmbd check that the session of second channel is in the session list of
first connection. If it is in session list, multichannel connection
should not be allowed.
Fixes: b95629435b ("ksmbd: fix racy issue from session lookup and expire")
Reported-by: Sean Heelan <seanheelan@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
In multichannel mode, UAF issue can occur in session_deregister
when the second channel sets up a session through the connection of
the first channel. session that is freed through the global session
table can be accessed again through ->sessions of connection.
Cc: stable@vger.kernel.org
Reported-by: Norbert Szetei <norbert@doyensec.com>
Tested-by: Norbert Szetei <norbert@doyensec.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Use aead_request_free() instead of kfree() to properly free memory
allocated by aead_request_alloc(). This ensures sensitive crypto data
is zeroed before being freed.
Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Pull vfs async dir updates from Christian Brauner:
"This contains cleanups that fell out of the work from async directory
handling:
- Change kern_path_locked() and user_path_locked_at() to never return
a negative dentry. This simplifies the usability of these helpers
in various places
- Drop d_exact_alias() from the remaining place in NFS where it is
still used. This also allows us to drop the d_exact_alias() helper
completely
- Drop an unnecessary call to fh_update() from nfsd_create_locked()
- Change i_op->mkdir() to return a struct dentry
Change vfs_mkdir() to return a dentry provided by the filesystems
which is hashed and positive. This allows us to reduce the number
of cases where the resulting dentry is not positive to very few
cases. The code in these places becomes simpler and easier to
understand.
- Repack DENTRY_* and LOOKUP_* flags"
* tag 'vfs-6.15-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
doc: fix inline emphasis warning
VFS: Change vfs_mkdir() to return the dentry.
nfs: change mkdir inode_operation to return alternate dentry if needed.
fuse: return correct dentry for ->mkdir
ceph: return the correct dentry on mkdir
hostfs: store inode in dentry after mkdir if possible.
Change inode_operations.mkdir to return struct dentry *
nfsd: drop fh_update() from S_IFDIR branch of nfsd_create_locked()
nfs/vfs: discard d_exact_alias()
VFS: add common error checks to lookup_one_qstr_excl()
VFS: change kern_path_locked() and user_path_locked_at() to never return negative dentry
VFS: repack LOOKUP_ bit flags.
VFS: repack DENTRY_ flags.
The users want to use Kerberos in ksmbd. SMB_SERVER_KERBEROS5 config is
enabled by default.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
->interim_entry of ksmbd_work could be deleted after oplock is freed.
We don't need to manage it with linked list. The interim request could be
immediately sent whenever a oplock break wait is needed.
Cc: stable@vger.kernel.org
Reported-by: Norbert Szetei <norbert@doyensec.com>
Tested-by: Norbert Szetei <norbert@doyensec.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
vfs_mkdir() does not guarantee to leave the child dentry hashed or make
it positive on success, and in many such cases the filesystem had to use
a different dentry which it can now return.
This patch changes vfs_mkdir() to return the dentry provided by the
filesystems which is hashed and positive when provided. This reduces
the number of cases where the resulting dentry is not positive to a
handful which don't deserve extra efforts.
The only callers of vfs_mkdir() which are interested in the resulting
inode are in-kernel filesystem clients: cachefiles, nfsd, smb/server.
The only filesystems that don't reliably provide the inode are:
- kernfs, tracefs which these clients are unlikely to be interested in
- cifs in some configurations would need to do a lookup to find the
created inode, but doesn't. cifs cannot be exported via NFS, is
unlikely to be used by cachefiles, and smb/server only has a soft
requirement for the inode, so this is unlikely to be a problem in
practice.
- hostfs, nfs, cifs may need to do a lookup (rarely for NFS) and it is
possible for a race to make that lookup fail. Actual failure
is unlikely and providing callers handle negative dentries graceful
they will fail-safe.
So this patch removes the lookup code in nfsd and smb/server and adjusts
them to fail safe if a negative dentry is provided:
- cache-files already fails safe by restarting the task from the
top - it still does with this change, though it no longer calls
cachefiles_put_directory() as that will crash if the dentry is
negative.
- nfsd reports "Server-fault" which it what it used to do if the lookup
failed. This will never happen on any file-systems that it can actually
export, so this is of no consequence. I removed the fh_update()
call as that is not needed and out-of-place. A subsequent
nfsd_create_setattr() call will call fh_update() when needed.
- smb/server only wants the inode to call ksmbd_smb_inherit_owner()
which updates ->i_uid (without calling notify_change() or similar)
which can be safely skipping on cifs (I hope).
If a different dentry is returned, the first one is put. If necessary
the fact that it is new can be determined by comparing pointers. A new
dentry will certainly have a new pointer (as the old is put after the
new is obtained).
Similarly if an error is returned (via ERR_PTR()) the original dentry is
put.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250227013949.536172-7-neilb@suse.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
parse_dcal() validate num_aces to allocate posix_ace_state_array.
if (num_aces > ULONG_MAX / sizeof(struct smb_ace *))
It is an incorrect validation that we can create an array of size ULONG_MAX.
smb_acl has ->size field to calculate actual number of aces in request buffer
size. Use this to check invalid num_aces.
Reported-by: Igor Leite Ladessa <igor-ladessa@hotmail.com>
Tested-by: Igor Leite Ladessa <igor-ladessa@hotmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2.4.5 in [MS-DTYP].pdf describe the data type of num_aces as le16.
AceCount (2 bytes): An unsigned 16-bit integer that specifies the count
of the number of ACE records in the ACL.
Change it to le16 and add reserved field to smb_acl struct.
Reported-by: Igor Leite Ladessa <igor-ladessa@hotmail.com>
Tested-by: Igor Leite Ladessa <igor-ladessa@hotmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
req->handle is allocated using ksmbd_acquire_id(&ipc_ida), based on
ida_alloc. req->handle from ksmbd_ipc_login_request and
FSCTL_PIPE_TRANSCEIVE ioctl can be same and it could lead to type confusion
between messages, resulting in access to unexpected parts of memory after
an incorrect delivery. ksmbd check type of ipc response but missing add
continue to check next ipc reponse.
Cc: stable@vger.kernel.org
Reported-by: Norbert Szetei <norbert@doyensec.com>
Tested-by: Norbert Szetei <norbert@doyensec.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
If osidoffset, gsidoffset and dacloffset could be greater than smb_ntsd
struct size. If it is smaller, It could cause slab-out-of-bounds.
And when validating sid, It need to check it included subauth array size.
Cc: stable@vger.kernel.org
Reported-by: Norbert Szetei <norbert@doyensec.com>
Tested-by: Norbert Szetei <norbert@doyensec.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Callers of lookup_one_qstr_excl() often check if the result is negative or
positive.
These changes can easily be moved into lookup_one_qstr_excl() by checking the
lookup flags:
LOOKUP_CREATE means it is NOT an error if the name doesn't exist.
LOOKUP_EXCL means it IS an error if the name DOES exist.
This patch adds these checks, then removes error checks from callers,
and ensures that appropriate flags are passed.
This subtly changes the meaning of LOOKUP_EXCL. Previously it could
only accompany LOOKUP_CREATE. Now it can accompany LOOKUP_RENAME_TARGET
as well. A couple of small changes are needed to accommodate this. The
NFS change is functionally a no-op but ensures nfs_is_exclusive_create() does
exactly what the name says.
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250217003020.3170652-3-neilb@suse.de
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Pull smb server updates from Steve French:
"Three ksmbd server fixes:
- Fix potential memory corruption in IPC calls
- Support FSCTL_QUERY_INTERFACE_INFO for more configurations
- Remove some unused functions"
* tag 'v6.14-rc-ksmbd-server-fixes' of git://git.samba.org/ksmbd:
ksmbd: fix integer overflows on 32 bit systems
ksmbd: browse interfaces list on FSCTL_QUERY_INTERFACE_INFO IOCTL
ksmbd: Remove unused functions
On 32bit systems the addition operations in ipc_msg_alloc() can
potentially overflow leading to memory corruption.
Add bounds checking using KSMBD_IPC_MAX_PAYLOAD to avoid overflow.
Fixes: 0626e6641f ("cifsd: add server handler for central processing and tranport layers")
Cc: stable@vger.kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
ksmbd.mount will give each interfaces list and bind_interfaces_only flags
to ksmbd server. Previously, the interfaces list was sent only
when bind_interfaces_only was enabled.
ksmbd server browse only interfaces list given from ksmbd.conf on
FSCTL_QUERY_INTERFACE_INFO IOCTL.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
ksmbd_rpc_rap() was added in 2021 as part of
commit 0626e6641f ("cifsd: add server handler for central processing and
tranport layers")
ksmbd_vfs_posix_lock_wait_timeout() was added in 2021 as part of
commit f441584858 ("cifsd: add file operations")
both have remained unused.
Remove them.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
When `ksmbd_vfs_kern_path_locked` met an error and it is not the last
entry, it will exit without restoring changed path buffer. But later this
buffer may be used as the filename for creation.
Fixes: c5a709f08d ("ksmbd: handle caseless file creation")
Signed-off-by: He Wang <xw897002528@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
In the smb2_send_interim_resp(), if ksmbd_alloc_work_struct()
fails to allocate a node, it returns a NULL pointer to the
in_work pointer. This can lead to an illegal memory write of
in_work->response_buf when allocate_interim_rsp_buf() attempts
to perform a kzalloc() on it.
To address this issue, incorporating a check for the return
value of ksmbd_alloc_work_struct() ensures that the function
returns immediately upon allocation failure, thereby preventing
the aforementioned illegal memory access.
Fixes: 041bba4414 ("ksmbd: fix wrong interim response on compound")
Signed-off-by: Wentao Liang <liangwentao@iscas.ac.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
