Commit Graph

931 Commits

Author SHA1 Message Date
Namjae Jeon
9fa26285ae ksmbd: keep compound responses on query info errors
Do not reset the RFC1002 length of the complete response when a query
info buffer is too small. The current command will add its error response
through ksmbd_iov_pin_rsp(), while resetting the base length can truncate
earlier responses in a compound request.

This lets ksmbd return the earlier responses and the query-info error
response together. Remove the now-unused rsp_org parameter from the pipe
query-info helpers.

Fixes: e2b76ab8b5 ("ksmbd: add support for read compound")
Reported-by: Mobin Aydinfar <mobin@mobintestserver.ir>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-09-15 22:28:52 +09:00
Namjae Jeon
f4fafaf021 ksmbd: fix partial normalized name responses
Windows may request FILE_NORMALIZED_NAME_INFORMATION with an output
buffer that only fits the fixed portion of the variable-length response.
Treat the fixed portion as FILE_NORMALIZED_NAME_INFORMATION_SIZE so ksmbd
returns STATUS_BUFFER_OVERFLOW instead of STATUS_INFO_LENGTH_MISMATCH.

This avoids rejecting valid partial normalized-name responses.

Fixes: 6b8b79226b ("ksmbd: fix partial file information responses")
Reported-by: Mobin Aydinfar <mobin@mobintestserver.ir>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-09-15 22:28:51 +09:00
Namjae Jeon
d7fd1f9860 ksmbd: follow SMB2 session expiration semantics
ksmbd_session_register() destroys valid sessions after ten seconds of
inactivity whenever a client starts another SessionSetup exchange. This
confuses Session.IdleTime with Session.ExpirationTime. Windows can create
additional authenticated sessions on an existing connection, so deleting
the older session invalidates its tree connects and makes mapped drives
fail with STATUS_NETWORK_NAME_DELETED.

The session expiration rules require the server to change a valid session
to expired only after its credential expiration time passes. A valid or
expired session otherwise keeps its connection from being scavenged.
Connections that have not negotiated a dialect, have no sessions, or have
only InProgress sessions are disconnected after an implementation-specific
timeout. Use the Windows-compatible 45 second value and run the expiration
check periodically for both TCP and SMB Direct.

Keep zero as an infinite credential expiration time, and count each
Valid-to-Expired transition. Set expired sessions to InProgress when they
reauthenticate. If authentication fails, remove the session from the
global and per-connection tables immediately, including SMB3 multichannel
connections.

Retain protection against abandoned SessionId-zero exchanges by allowing
only one InProgress authentication per connection. Additional exchanges
fail with STATUS_INSUFFICIENT_RESOURCES, and stale InProgress sessions are
reaped after the same 45 second setup timeout. This bounds the original
unauthenticated memory-exhaustion path without evicting established
sessions.

Fixes: ea174a9189 ("ksmbd: destroy expired sessions")
Reported-by: Mobin Aydinfar <mobin@mobintestserver.ir>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-09-14 20:14:35 +09:00
Kees Cook
3a2c4d55e3 treewide: refresh kmalloc_obj() conversions
This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci

This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.

Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.

Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>
2026-09-04 21:37:00 -07:00
Cen Zhang (Microsoft Security FORGE Labs)
b5ec6c462a ksmbd: fix tree connection use-after-free in smb2_tree_connect()
ksmbd_tree_conn_connect() publishes a new tree connection in
sess->tree_conns with a single reference and returns its pointer to
smb2_tree_connect(). The handler continues to initialize the object and
build the response after publication. A concurrent session logoff can
erase the connection and drop that reference, freeing the object while
the handler still uses it.

BUG: KASAN: slab-use-after-free in smb2_tree_connect+0xe3d/0xf90
  smb2_tree_connect (fs/smb/server/smb2pdu.c:2872)
  handle_ksmbd_work
  process_one_work
  worker_thread
  kthread

After xa_store() succeeds, take a second reference before releasing
tree_conns_lock. The original reference belongs to the xarray entry and
the second belongs to the creating smb2_tree_connect() handler.

Keep the references balanced in every path:

- On normal exit or an error after publication, smb2_tree_connect()
  drops its creator reference. Error cleanup also calls
  ksmbd_tree_conn_disconnect(), which drops the xarray reference only if
  it removes the exact entry.
- SMB2 TREE_DISCONNECT uses the same helper to remove the entry and drop
  its xarray reference. The request's existing lookup reference remains
  owned by the request and is released by the existing cleanup.
- Session LOGOFF removes each entry and drops its xarray reference. If
  it wins the race, later cleanup sees that the entry is gone and does
  not drop that reference again.

To enforce this ownership, claim the disconnected state and erase the
exact entry atomically under tree_conns_lock. This guarantees one drop
for the xarray reference and one drop by each in-flight user, regardless
of which teardown path wins. If logoff removes the entry before
initialization completes, fail the connect instead of marking the
detached object TREE_CONNECTED.

Fixes: 33b235a6e6 ("ksmbd: fix race condition between tree conn lookup and disconnect")
Reported-by: Xiang Mei (Microsoft) <xmei5@asu.edu>
Cc: AutonomousCodeSecurity@microsoft.com
Cc: stable@vger.kernel.org
Signed-off-by: Cen Zhang (Microsoft Security FORGE Labs) <cenzhang@linux.microsoft.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-09-02 17:58:35 +09:00
Alon Shakevsky
0480cee8cc ksmbd: validate COPYCHUNK source and target ranges
ksmbd_vfs_copy_file_ranges() rejects negative source offsets in the
copy loop, but it does not validate target offsets. It also calculates
lock and overlap endpoints before ensuring that either range fits within
MAX_LFS_FILESIZE.

When the target is an alternate data stream, the buffered path passes a
negative target offset to ksmbd_vfs_stream_write(). Let n be Length and
let -d be TargetOffset, where 0 < d < n <= XATTR_SIZE_MAX. For an empty
stream, the writer allocates n - d bytes, then copies n bytes starting d
bytes before the allocation. An authenticated SMB client can control d
and the source data, overwrite kernel heap memory, and crash the host.

Validate both ranges before lock, overlap, or I/O calculations.

Fixes: 8482150a07 ("ksmbd: support copychunk for alternate data streams")
Assisted-by: Antiproof:GPT-5.6-Sol
Signed-off-by: Alon Shakevsky <shakevsky@berkeley.edu>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-09-02 17:58:15 +09:00
Abdifatah Suruur
0e75389962 ksmbd: fix use-after-free in oplock break notification
smb2_oplock_break_noti() reads opinfo->conn without any lock and
dereferences it after two allocations which may sleep.  When the
durable handle owning the oplock is disconnected, session_fd_check()
clears opinfo->conn and drops its conn reference under ci->m_lock, and
the last ksmbd_conn_put() frees the connection.  A break triggered by
another connection that races with the teardown can then resurrect the
freed connection: ksmbd_conn_get() is a plain atomic_inc, and the
queued break work later dereferences the stale conn via
ksmbd_conn_write(), a use-after-free reachable by any authenticated
client holding a durable batch oplock.

Thread the caller's inode into the notification path instead of taking
a new reference on it.  Every caller of oplock_break() already holds a
live ksmbd_file (or an explicit ksmbd_inode_lookup_lock() reference,
in the parent lease break paths) on the inode that owns the break
target's oplock list, so ci cannot be freed during the call, and its
lock can be taken without dereferencing opinfo->o_fp, which a
concurrent close may free.  Select and pin the connection under
ci->m_lock, the same lock session_fd_check() and
ksmbd_reopen_durable_fd() use to update opinfo->conn, so a concurrent
detach either loses the race to the clear or keeps the connection
alive until the notification work releases it.  Transfer the reference
to the work item and release it on allocation failures.

Fixes: b003086d76 ("ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers")
Cc: stable@vger.kernel.org
Signed-off-by: Abdifatah Suruur <suruurism@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-09-02 17:58:11 +09:00
Namjae Jeon
636abbe7a6 ksmbd: fix sparc build with atomic work state
Use an unsigned int for the work state so xchg() uses a supported
4-byte operation on sparc.

Fixes: d12168084c ("ksmbd: safely drain sessions during logoff")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202609021157.8f7Wx34I-lkp@intel.com/
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-09-02 17:58:00 +09:00
Alon Shakevsky
ba9572bc43 ksmbd: validate normalized name response length
FILE_NORMALIZED_NAME_INFORMATION converts the open file path to UTF-16.
smb2_allocate_rsp_buf() leaves these responses in the 448-byte small
buffer, and get_file_normalized_name_info() converts the path without
checking the remaining space.

An authenticated client can query a long path and make
smbConvertToUTF16() write beyond work->response_buf.

Use the large response buffer for normalized-name queries. Before
conversion, verify that the response has room for the worst-case UTF-16
output and its terminator.

Fixes: 10aeff72ab ("ksmbd: support normalized name information")
Assisted-by: Antiproof:GPT-5.6-Sol
Signed-off-by: Alon Shakevsky <shakevsky@berkeley.edu>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-31 19:27:36 +09:00
Namjae Jeon
a506290f59 ksmbd: fix listener task lifetime on netdev events
The listener thread exits when its listening socket is shutdown. The
netdevice notifier shuts down the socket before calling kthread_stop(), so
the task_struct can be freed before kthread_stop() gets its reference.

Create the listener in a stopped state and hold an extra task_struct
reference until kthread_stop_put() completes. Also stop and release
listeners before freeing their interface records during TCP teardown.

Fixes: 3316a8fc84 ("ksmbd: server: avoid busy polling in accept loop")
Reported-by: Farhad Alemi <farhad.alemi@berkeley.edu>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-31 19:27:11 +09:00
Namjae Jeon
f25e93768f ksmbd: prevent out-of-bounds reads in share config responses
Validate IPC share configuration payload sizes before consuming
variable-length fields. Bound veto list parsing and account for
the separator byte when deriving the path length.

Fixes: a677ebd8ca ("ksmbd: validate payload size in ipc response")
Reported-by: Kanishka De Silva <kpskanna1915@gmail.com>
Reported-by: Farhad Alemi <farhad.alemi@berkeley.edu>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-31 19:27:06 +09:00
Namjae Jeon
feca5e70fc ksmbd: rate limit unmapped SID errors
A client can include many structurally valid but unmapped SIDs in a DACL.
Logging every mapping failure lets one request generate hundreds of kernel
error messages.

Rate limit the message to prevent an authenticated client from flooding
the kernel log.

Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Reported-by: Cheryl Babcock <cheryl@renat.io>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-31 19:26:45 +09:00
Namjae Jeon
c61dc7b1b4 ksmbd: propagate DACL parsing errors
parse_dacl() silently accepts truncated ACEs and allocation failures,
allowing set_info_sec() to continue with an incomplete ACL conversion.

Return parsing and allocation errors to parse_sec_desc() so malformed
security descriptors are rejected before inode attributes or ACL xattrs
are updated.

Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Reported-by: Cheryl Babcock <cheryl@renat.io>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-31 19:26:38 +09:00
Namjae Jeon
73f860489e ksmbd: zero pipe read compound padding
Compound response handling extends the last response iov to an eight-byte
boundary.

smb2_read_pipe() allocates only the payload size, so the alignment padding
can expose up to seven bytes of uninitialized kernel heap memory.

Allocate the aligned size and clear the unused tail before pinning the
response buffer.

Fixes: e2b76ab8b5 ("ksmbd: add support for read compound")
Reported-by: Cheryl Babcock <cheryl@renat.io>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-31 19:26:34 +09:00
Namjae Jeon
d12168084c ksmbd: safely drain sessions during logoff
SMB3 multichannel allows requests for one session to run on multiple
connections. Wait for all channels bound to a session before freeing
shared session objects.

A deferred byte-range lock remains counted as a running request and only
wakes when its file closes. Wake blocked locks during the drain without
unpublishing or modifying their file objects. Synchronous CANCEL requests
must invoke their cancellation callback to wake pending operations, while
CHANGE_NOTIFY completion remains specific to the asynchronous path.

Serialize session teardown with channel registration and previous-session
cleanup, and use atomic work-state transitions so LOGOFF, CANCEL, and
connection teardown invoke cancellation callbacks only once.

Fixes: 76e98a158b ("ksmbd: fix race condition between destroy_previous_session() and smb2 operations()")
Reported-by: Cheryl Babcock <cheryl@renat.io>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-31 19:26:30 +09:00
Aleksandr Khromov
db2267b27c ksmbd: fill in FileSysIdentifier in FS_POSIX_INFORMATION
smb2_get_info_filesystem() reports 56 bytes for FS_POSIX_INFORMATION,
that is the whole of FILE_SYSTEM_POSIX_INFO, but never assigns
FileSysIdentifier.  Those eight bytes go to the client as they are found
in the response buffer.

The buffer is zeroed on allocation, so a standalone request leaks
nothing.  A compound request can leak: the offset of the next response
is advanced by the length pinned for the previous one, so a reply that
was written into the buffer and then dropped in favour of the short
error response of smb2_set_err_rsp() stays there, and the next reply is
laid over it with only the header cleared.

Report the file system id statfs() returned, which is what the field is
for.  FileSysIdentifier is __le64 and f_fsid is a pair of ints, so
assemble the value first, val[0] as the low half, and convert it on the
way out.

Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org
Signed-off-by: Aleksandr Khromov <haa@amicon.ru>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-31 19:26:17 +09:00
Aleksandr Khromov
c0cd3fc682 ksmbd: initialize FileSystemControlFlags in FS_CONTROL_INFORMATION
smb2_get_info_filesystem() reports 48 bytes for FS_CONTROL_INFORMATION,
that is the whole of struct smb2_fs_control_info, but never assigns
FileSystemControlFlags.  Those four bytes go to the client as they are
found in the response buffer.

The buffer is zeroed on allocation, so a standalone request leaks
nothing.  A compound request can leak: the offset of the next response
is advanced by the length pinned for the previous one, so a reply that
was written into the buffer and then dropped in favour of the short
error response of smb2_set_err_rsp() stays there, and the next reply is
laid over it with only the header cleared.

ksmbd does not implement quota tracking, so report no control flags.

Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org
Signed-off-by: Aleksandr Khromov <haa@amicon.ru>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-31 19:26:12 +09:00
Aleksandr Khromov
399aa12450 ksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it in
smb2_get_info_filesystem() reports 64 bytes for FS_OBJECT_ID_INFORMATION,
that is the whole of struct object_id_info, but writes only 46 of them:

 - objid[] is 16 bytes, and when the volume UUID is not available only
   sizeof(stfs.f_fsid) (8) bytes are copied into it;
 - extended_info.version_string[] is STRING_LENGTH (28) bytes, and only
   strlen("1.1.0") (5) bytes are copied into it.

The response buffer is zeroed on allocation (kvzalloc() in
smb2_allocate_rsp_buf()), so for a standalone request the remaining 31
bytes are zero.  In a compound request they need not be.  The offset of
the next response is advanced by the length pinned for the previous one,
so if a preceding command wrote its reply into the buffer and then
failed, smb2_set_err_rsp() pins only the short error response and the
next reply lands inside the area that has already been written.  Only
the header is cleared there:

	memset((char *)rsp_hdr, 0, sizeof(struct smb2_hdr) + 2);

The client then receives up to 31 bytes of a response it was not meant
to see, including one that failed with an access denied error.

Clear the structure before filling it in.  As a side effect
version_string is now NUL terminated.

Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Suggested-by: ChenXiaoSong <chenxiaosong@chenxiaosong.com>
Cc: stable@vger.kernel.org
Signed-off-by: Aleksandr Khromov <haa@amicon.ru>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-31 19:26:07 +09:00
Linus Torvalds
61a09cfc12 This contains a set of 142 SMB server updates focused on SMB2 command
sequencing, SMB3 request replay and encryption, Apple Time Machine
 interoperability, protocol-compatibility fixes validated with smbtorture,
 security hardening, SMB Direct transport support, connection reliability,
 and other correctness improvements.
 
 New features:
 
  - Implement the SMB2 command sequence window.
    Enforce the credit-based MessageId range for each connection, rejecting
    out-of-window, duplicate, and wrapped sequence numbers. This prevents
    invalid requests and same-channel replays from being processed.
 
  - Add SMB3 request replay support.
    SMB3 clients may resend requests with SMB2_FLAGS_REPLAY_OPERATION after
    a channel disconnect when the original response was lost. Track the
    required channel and open state to safely handle durable CREATE replays
    and make oplock, lease, and lock replays idempotent, avoiding duplicate
    state changes and improving multichannel reconnect reliability.
 
  - Add opt-in Apple Time Machine support.
    Implement the AAPL negotiation and related Finder, stream, COPYCHUNK,
    sparse-file, CHANGE_NOTIFY, and RPC compatibility required for Time
    Machine shares, allowing macOS backupd to use ksmbd for backups.
 
  - Add per-share SMB3 encryption support.
    Allow individual shares to require SMB3 encryption by advertising
    SMB2_SHAREFLAG_ENCRYPT_DATA in TREE_CONNECT responses and rejecting
    unencrypted tree connects and plaintext requests for protected shares.
 
  - Add SMB Direct RDMA encryption support.
    Extend SMB Direct to support SMB3 encrypted payloads over RDMA, with
    transform negotiation and encryption/decryption for RDMA READ/WRITE.
 
 Other changes:
 
  - Parse and retain AppInstanceVersion contexts, enforce version ordering,
    close older active handles for newer takeovers, and reject invalid or
    unversioned opens according to the SMB2 semantics.
 
  - Accept durable reconnect requests that omit VolatileFileId when the
    persistent ID and reconnect context identify the handle, while
    continuing to reject explicit volatile-ID mismatches.
 
  - Fix SMB2/SMB3 protocol validation and security issues, including request
    offsets, file and object IDs, IPC responses, output buffer sizes,
    SMB3.1.1 binding validation, signing-required handling, durable handles,
    ACLs, maximal access, and security information.
 
  - Fix heap out-of-bounds accesses, use-after-free bugs, memory leaks,
    invalid pointer dereferences, and sensitive-data lifetime issues in
    authentication, Kerberos, preauthentication, sessions, connections,
    and module teardown.
 
  - Correct alternate-data-stream and named-stream handling, COPYCHUNK
    behavior, sparse-file and compression attributes, allocated-range
    queries, file trimming, duplicate extents, DOS attributes, snapshots,
    normalized names, and partial information responses.
 
  - Fix locking, lease, oplock, durable reconnect, async request, and
    CHANGE_NOTIFY races, including deferred-lock rollback, parent directory
    lease notifications, and connection teardown lifetime bugs.
 
  - Fix SMB3 encryption handling for compressed requests, expired encrypted
    sessions, interim responses, bound multichannel connections, and
    decryption failures.
 
  - Fix SMB3 multichannel session lookup and session state transitions so
    changes are scoped to the correct bound connections and cannot revive
    connections that are already shutting down.
 
  - Fix DACL access checks so ACE walks are bounded by the declared DACL
    size, preventing data beyond the DACL boundary from being interpreted
    during access validation.
 
  - Fix session accounting and lifetime issues, including session counter
    updates during publication and removal, session leaks on registration
    failure, and procfs creation diagnostics.
 
  - Improve TCP connection reliability by enabling TCP keepalive for
    accepted connections and preserving TCP timers for kernel sockets,
    preventing silent peers from holding connections indefinitely.
 
  - Fix smbdirect RDMA cleanup ordering for completion queues, QPs, child
    sockets, and listener locking.
 
  - Improve async response framing, multi-iovec signing, RPC pipe status
    handling, and ksmbd procfs monitoring for server, share, connection,
    session, and open-file state.
 
  - Remove the obsolete DES crypto header and Kconfig dependency now that
    NTLMv1 support has been removed.
 
  - Update the ksmbd repository URL in MAINTAINERS and add an additional
    KSMBD reviewer.
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Merge tag 'ksmbd-for-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/smb

Pull smb server updates from Namjae Jeon:
 "This contains server updates focused on SMB2 command sequencing, SMB3
  request replay and encryption, Apple Time Machine interoperability,
  protocol-compatibility fixes validated with smbtorture, security
  hardening, SMB Direct transport support, connection reliability, and
  other correctness improvements.

  New features:

   - Implement the SMB2 command sequence window

     Enforce the credit-based MessageId range for each connection,
     rejecting out-of-window, duplicate, and wrapped sequence numbers.
     This prevents invalid requests and same-channel replays from being
     processed

   - Add SMB3 request replay support

     SMB3 clients may resend requests with SMB2_FLAGS_REPLAY_OPERATION
     after a channel disconnect when the original response was lost.
     Track the required channel and open state to safely handle durable
     CREATE replays and make oplock, lease, and lock replays idempotent,
     avoiding duplicate state changes and improving multichannel
     reconnect reliability

   - Add opt-in Apple Time Machine support

     Implement the AAPL negotiation and related Finder, stream,
     COPYCHUNK, sparse-file, CHANGE_NOTIFY, and RPC compatibility
     required for Time Machine shares, allowing macOS backupd to use
     ksmbd for backups

   - Add per-share SMB3 encryption support

     Allow individual shares to require SMB3 encryption by advertising
     SMB2_SHAREFLAG_ENCRYPT_DATA in TREE_CONNECT responses and rejecting
     unencrypted tree connects and plaintext requests for protected
     shares

   - Add SMB Direct RDMA encryption support

     Extend SMB Direct to support SMB3 encrypted payloads over RDMA,
     with transform negotiation and encryption/decryption for RDMA
     READ/WRITE

  Other changes:

   - Parse and retain AppInstanceVersion contexts, enforce version
     ordering, close older active handles for newer takeovers, and
     reject invalid or unversioned opens according to the SMB2 semantics

   - Accept durable reconnect requests that omit VolatileFileId when the
     persistent ID and reconnect context identify the handle, while
     continuing to reject explicit volatile-ID mismatches

   - Fix SMB2/SMB3 protocol validation and security issues, including
     request offsets, file and object IDs, IPC responses, output buffer
     sizes, SMB3.1.1 binding validation, signing-required handling,
     durable handles, ACLs, maximal access, and security information

   - Fix heap out-of-bounds accesses, use-after-free bugs, memory leaks,
     invalid pointer dereferences, and sensitive-data lifetime issues in
     authentication, Kerberos, preauthentication, sessions, connections,
     and module teardown

   - Correct alternate-data-stream and named-stream handling, COPYCHUNK
     behavior, sparse-file and compression attributes, allocated-range
     queries, file trimming, duplicate extents, DOS attributes,
     snapshots, normalized names, and partial information responses

   - Fix locking, lease, oplock, durable reconnect, async request, and
     CHANGE_NOTIFY races, including deferred-lock rollback, parent
     directory lease notifications, and connection teardown lifetime
     bugs

   - Fix SMB3 encryption handling for compressed requests, expired
     encrypted sessions, interim responses, bound multichannel
     connections, and decryption failures

   - Fix SMB3 multichannel session lookup and session state transitions
     so changes are scoped to the correct bound connections and cannot
     revive connections that are already shutting down

   - Fix DACL access checks so ACE walks are bounded by the declared
     DACL size, preventing data beyond the DACL boundary from being
     interpreted during access validation

   - Fix session accounting and lifetime issues, including session
     counter updates during publication and removal, session leaks on
     registration failure, and procfs creation diagnostics

   - Improve TCP connection reliability by enabling TCP keepalive for
     accepted connections and preserving TCP timers for kernel sockets,
     preventing silent peers from holding connections indefinitely

   - Fix smbdirect RDMA cleanup ordering for completion queues, QPs,
     child sockets, and listener locking

   - Improve async response framing, multi-iovec signing, RPC pipe
     status handling, and ksmbd procfs monitoring for server, share,
     connection, session, and open-file state

   - Remove the obsolete DES crypto header and Kconfig dependency now
     that NTLMv1 support has been removed

   - Update the ksmbd repository URL in MAINTAINERS and add an
     additional KSMBD reviewer"

* tag 'ksmbd-for-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/smb: (142 commits)
  MAINTAINERS: update ksmbd repository URL
  MAINTAINERS: add myself as KSMBD reviewer
  smb: server: remove unused DES crypto header
  smb: server: Remove obsolete "select CRYPTO_LIB_DES" from Kconfig file
  ksmbd: keep TCP timers alive for kernel sockets
  ksmbd: enable TCP keepalive for accepted connections
  smb/server: fix session counter on session removal
  smb/server: update session counter under sessions table lock
  smb/server: fix session leak in ksmbd_session_register()
  smb/server: warn if ksmbd_proc_create() fails
  ksmbd: bound smb_check_perm_dacl() ACE walks by DACL size
  ksmbd: make RDMA encryption diagnostics conditional
  ksmbd: add SMB Direct RDMA encryption transform
  ksmbd: handle encrypted compressed requests
  ksmbd: decrypt requests from expired encrypted sessions
  ksmbd: disconnect on SMB3 decryption failure
  ksmbd: encrypt interim responses to encrypted requests
  ksmbd: scope session state changes to bound connections
  ksmbd: fix encrypted request lookup on bound channels
  ksmbd: add per-share SMB3 encryption enforcement
  ...
2026-08-23 08:41:36 -07:00
Namjae Jeon
c5e640fe34 smb: server: remove unused DES crypto header
The DES crypto header is no longer used after the removal of NTLMv1
authentication. Remove it now that the server no longer selects
CRYPTO_LIB_DES.

Fixes: ce812992f2 ("ksmbd: remove NTLMv1 authentication")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-20 22:56:15 +09:00
Thomas Huth
ed91d80242 smb: server: Remove obsolete "select CRYPTO_LIB_DES" from Kconfig file
The DES encryption in the smb server code has been removed in 2021
with the removal of the insecure NTLMv1 authentication code. Thus
we don't need this "select" statement here anymore.

Fixes: ce812992f2 ("ksmbd: remove NTLMv1 authentication")
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-20 22:56:13 +09:00
Namjae Jeon
80b6367ec3 ksmbd: keep TCP timers alive for kernel sockets
ksmbd creates its listening socket with sock_create_kern(). Kernel
sockets do not hold a network namespace reference by default. Accepted
sockets inherit this state.

When an accepted socket is released, tcp_close() clears its pending TCP
timers for a kernel socket after the socket enters an orphaned state. If
the peer is unreachable while ksmbd sends a FIN, this can leave a
FIN-WAIT-1 orphan without a retransmission timer.

Upgrade the listening socket's network namespace reference before
kernel_listen(). Accepted sockets inherit the reference, so the TCP
stack can keep the retransmission timer active and apply its normal
orphan retry policy.

Preserve the existing graceful shutdown behavior.

Link: https://github.com/openwrt/openwrt/issues/24744
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-20 22:56:12 +09:00
Namjae Jeon
56549c18a4 ksmbd: enable TCP keepalive for accepted connections
A client that disappears without sending a FIN or RST can leave its
ksmbd connection in ESTABLISHED indefinitely. ksmbd sets a socket
receive timeout, but the connection receive loop retries timeout errors
without a limit, so the connection remains in conn_list and consumes the
per-IP connection quota.

Enable SO_KEEPALIVE on accepted TCP sockets so the TCP stack can detect a
silent peer failure. The keepalive idle time, interval, and probe count
remain controlled by the existing TCP sysctl settings.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-20 22:56:10 +09:00
Linus Torvalds
d47db9bf50 Crypto library updates for 7.3
Add library APIs for most AES encryption modes that are used in the
 kernel (ECB, CBC, CBC-CTS, CTR, XCTR, XTS, GCM, CCM).
 
 These AES modes have many in-kernel users that are currently using the
 crypto_skcipher or crypto_aead APIs. These existing APIs are difficult
 to use and inefficient. Until now, the lack of proper library support
 for these has been the main gap in the crypto library.
 
 This set of changes is the next stage of addressing it:
 
   - Implement the new APIs on top of the existing support for
     single-block AES in the library.
 
   - Fully document the new APIs.
 
   - Migrate the only user of the old AES-GCM library API to the new,
     more flexible API; then remove the old API and its implementation.
 
   - Wire up the new APIs to the traditional crypto API by adding
     crypto_skcipher and crypto_aead algorithms.
 
     This makes the new APIs be covered by the traditional crypto API's
     self-tests. It also makes them be already used for real on systems
     that don't have architecture-optimized code for these modes.
 
     But most importantly, this is a prerequisite for migrating the
     architecture-optimized code for these AES modes (i.e.
     arch/*/crypto/aes*) into the library, which as usual will
     eliminate a lot of redundant "glue" code.
 
 Note that unlike some of the other algorithms that have been migrated
 to the library, e.g. SHA-512, for these AES modes there was too much
 to get done in one cycle. Nor did it make sense to handle these modes
 one at a time, because they tend to be coupled together or depend on
 each other, especially in the architecture-optimized AES code.
 
 Thus, most of the benefits (reductions in lines of code, performance
 improvements, etc.) will follow in later cycles when
 architecture-optimized code is migrated into the library and users of
 crypto_skcipher and crypto_aead are updated to use the new APIs.
 
 The design of the new APIs was informed by writing proof-of-concept
 patches for many kernel subsystems currently accessing these same
 algorithms via crypto_skcipher or crypto_aead (patches 18-33 of
 https://lore.kernel.org/r/20260707053503.209874-1-ebiggers@kernel.org/).
 
 While those patches will be resent for real later, the total diffstat
 for them was negative 1905 lines. So clearly the new APIs are quite a
 bit easier to use and align better with what users actually need.
 
 Besides the new AES encryption APIs, there are also a few changes for
 improved AES-CMAC key and context zeroization.
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Merge tag 'libcrypto-updates-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux

Pull crypto library updates from Eric Biggers:
 "Add library APIs for most AES encryption modes that are used in the
  kernel (ECB, CBC, CBC-CTS, CTR, XCTR, XTS, GCM, CCM).

  These AES modes have many in-kernel users that are currently using the
  crypto_skcipher or crypto_aead APIs. These existing APIs are difficult
  to use and inefficient. Until now, the lack of proper library support
  for these has been the main gap in the crypto library.

  This set of changes is the next stage of addressing it:

   - Implement the new APIs on top of the existing support for
     single-block AES in the library.

   - Fully document the new APIs.

   - Migrate the only user of the old AES-GCM library API to the new,
     more flexible API; then remove the old API and its implementation.

   - Wire up the new APIs to the traditional crypto API by adding
     crypto_skcipher and crypto_aead algorithms.

     This makes the new APIs be covered by the traditional crypto API's
     self-tests. It also makes them be already used for real on systems
     that don't have architecture-optimized code for these modes.

     But most importantly, this is a prerequisite for migrating the
     architecture-optimized code for these AES modes (i.e.
     arch/*/crypto/aes*) into the library, which as usual will eliminate
     a lot of redundant "glue" code.

  Note that unlike some of the other algorithms that have been migrated
  to the library, e.g. SHA-512, for these AES modes there was too much
  to get done in one cycle. Nor did it make sense to handle these modes
  one at a time, because they tend to be coupled together or depend on
  each other, especially in the architecture-optimized AES code.

  Thus, most of the benefits (reductions in lines of code, performance
  improvements, etc.) will follow in later cycles when
  architecture-optimized code is migrated into the library and users of
  crypto_skcipher and crypto_aead are updated to use the new APIs.

  The design of the new APIs was informed by writing proof-of-concept
  patches for many kernel subsystems currently accessing these same
  algorithms via crypto_skcipher or crypto_aead (patches 18-33 of
  https://lore.kernel.org/r/20260707053503.209874-1-ebiggers@kernel.org/).

  While those patches will be resent for real later, the total diffstat
  for them was negative 1905 lines. So clearly the new APIs are quite a
  bit easier to use and align better with what users actually need.

  Besides the new AES encryption APIs, there are also a few changes for
  improved AES-CMAC key and context zeroization"

* tag 'libcrypto-updates-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux:
  mac80211: fils_aead: Use __cleanup() instead of memzero_explicit()
  Bluetooth: SMP: clear the aes_cmac_key when done
  smb: clear the aes_cmac_key and aes_cmac_ctx when done
  lib/crypto: aes-cmac: Add zeroization functions
  lib/crypto: aesgcm: Remove old AES-GCM library
  x86/sev: Remove obsolete virtual address check
  x86/sev: Use new AES-GCM library
  crypto: aes - Add CCM support using library
  crypto: aes - Add GCM support using library
  crypto: aes - Add XTS support using library
  crypto: aes - Add CTR and XCTR support using library
  crypto: aes - Add CBC and CBC-CTS support using library
  crypto: aes - Add ECB support using library
  lib/crypto: aes: Add CCM support
  lib/crypto: aes: Add GCM support
  lib/crypto: aes: Add XTS support
  lib/crypto: aes: Add CTR and XCTR support
  lib/crypto: aes: Add CBC and CBC-CTS support
  lib/crypto: aes: Add ECB support
  crypto: xts - Split out __xts_verify_key() helper
2026-08-17 19:16:42 -07:00
Linus Torvalds
fff0150b02 vfs-7.3-rc1.kthread
Please consider pulling these changes from the signed vfs-7.3-rc1.kthread tag.
 
 Thanks!
 Christian
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Merge tag 'vfs-7.3-rc1.kthread' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull kthread vfs updates from Christian Brauner:
 "This stops kernel threads from sharing filesystem state with
  userspace. This work is about 3 cycles old and has been in -next
  for about that time.

  When the kernel boots init_task creates PID 1 and then kthreadd. From
  that point every kthread and PID 1 share the same fs_struct. That is
  why pivot_root() has to rewrite the fs_struct of all kthreads. The
  rewriting exists so that kthreads can use init's filesystem state when
  they want to. It also means userspace can move the ground out from
  under the kernel.

  PID 1 now gets a completely separate fs_struct. All kthreads are
  anchored in a private SB_KERNMOUNT instance of nullfs that cannot be
  mounted on and cannot be used to follow other mounts. Userspace init
  can no longer affect kthread filesystem state and kthreads can no
  longer affect userspace fs state without explicit opting in to that.

  Path lookup from a kthread now fails by default. It makes it
  deliberately hard to offload security sensitive operations into init's
  filesystem state from a kthread.

  Places that legitimately need to look something up there opt in
  through the new scoped_with_init_fs() which temporarily overrides the
  caller's fs_struct with init's. usermodehelpers remain the only kernel
  tasks that genuinely share init's filesystem state, since they execute
  random binaries in the root filesystem (excellent...).

  The visible result is that /proc/2/root is a nullfs with an empty
  mountinfo while /proc/1/root is the real root"

* tag 'vfs-7.3-rc1.kthread' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (26 commits)
  initramfs_test: use test init/exit hooks to override init fs
  fs: stop rewriting paths for PF_EXITING | PF_DUMPCORE
  fs: stop rewriting kthread fs structs
  fs: start all kthreads in nullfs
  nullfs: make nullfs multi-instance
  devtmpfs: create private mount namespace
  fs: add umh argument to struct kernel_clone_args
  fs: stop sharing fs_struct between init_task and pid 1
  af_unix: use scoped_with_init_fs() for coredump socket lookup
  initramfs: use scoped_with_init_fs() for rootfs unpacking
  pnfs/blocklayout: use scoped_with_init_fs() for SCSI device lookup
  ksmbd: use scoped_with_init_fs() for VFS path operations
  ksmbd: use scoped_with_init_fs() for filesystem info path lookup
  ksmbd: use scoped_with_init_fs() for share path resolution
  fs: use scoped_with_init_fs() for kernel_read_file_from_path_initns()
  coredump: use scoped_with_init_fs() for coredump path resolution
  btrfs: use scoped_with_init_fs() for update_dev_time()
  scsi: target: use scoped_with_init_fs() for APTPL metadata
  scsi: target: use scoped_with_init_fs() for ALUA metadata
  crypto: ccp: use scoped_with_init_fs() for SEV file access
  ...
2026-08-17 11:35:12 -07:00
Ze Tan
7de5cf9bcf smb/server: fix session counter on session removal
See the procedure below:

  smb2_sess_setup
    ksmbd_smb2_session_create
      __session_create
        hash_add(sessions_table, &sess->hlist, sess->id)
        ksmbd_counter_inc(KSMBD_COUNTER_SESSIONS)
  ksmbd_conn_handler_loop
    ksmbd_server_terminate_conn
      ksmbd_sessions_deregister
        hash_del(&sess->hlist)
        // do not decrement KSMBD_COUNTER_SESSIONS

KSMBD_COUNTER_SESSIONS tracks sessions published in sessions_table, but
session removal does not decrement it. The value therefore keeps growing
after sessions are expired, rejected during registration, or removed on
the last channel disconnect.

Fixes: b38f99c121 ("ksmbd: add procfs interface for runtime monitoring and statistics")
Signed-off-by: Ze Tan <tanze@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:27 +09:00
Ze Tan
492b24b5b6 smb/server: update session counter under sessions table lock
KSMBD_COUNTER_SESSIONS tracks sessions published in sessions_table.
Increment it while holding sessions_table_lock so publishing a session and
updating the counter happen together.

Fixes: b38f99c121 ("ksmbd: add procfs interface for runtime monitoring and statistics")
Signed-off-by: Ze Tan <tanze@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:26 +09:00
Ze Tan
99b25b046e smb/server: fix session leak in ksmbd_session_register()
See the procedure below:

  smb2_sess_setup
    ksmbd_smb2_session_create
      __session_create
        atomic_set(&sess->refcnt, 2)
        hash_add(sessions_table, &sess->hlist, sess->id)
    ksmbd_session_register
      xa_store(&conn->sessions, sess->id, sess) // fail
    ksmbd_user_session_put
      atomic_dec(&sess->refcnt) // refcnt is 1, session is not freed

Remove the session from sessions_table and drop its table reference if
xa_store() fails.

Fixes: f5c779b7dd ("ksmbd: fix racy issue from session setup and logoff")
Signed-off-by: Ze Tan <tanze@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:26 +09:00
Ze Tan
9a74739026 smb/server: warn if ksmbd_proc_create() fails
Print a warning if the sessions procfs entry cannot be created.

Signed-off-by: Ze Tan <tanze@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:26 +09:00
Hang Nan
79decd88dd ksmbd: bound smb_check_perm_dacl() ACE walks by DACL size
smb_check_perm_dacl() validates that the DACL fits inside the NT
security descriptor, but then bounds its two ACE walks by the
remaining NTSD length (acl_size) rather than the DACL's declared
size (pdacl_size).

When pdacl->size is smaller than the trailing NTSD buffer, bytes
after the declared DACL boundary - still inside the stored security
descriptor - are parsed as ACEs during access checks.  A crafted
DACL can place an access-granting ACE beyond pdacl->size, and the
current code accepts it during SMB2_CREATE access validation, while
parse_dacl() and smb_inherit_dacl() stop at pdacl_size.

Bound both ACE walks by pdacl_size to match the DACL boundary
semantics used elsewhere in the server.

Validation:
- semantic KUnit harness shows the post-boundary ACE is selected
  before the fix and rejected (EACCES) after it
- linux master (7.2-rc6), x86_64

Fixes: 8f0541186e ("ksmbd: fix heap-based overflow in set_ntacl_dacl()")
Signed-off-by: Hang Nan <2122295973@qq.com>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:26 +09:00
Namjae Jeon
f7157d148d ksmbd: make RDMA encryption diagnostics conditional
The temporary RDMA encryption diagnostics logged every SMB3 request
and successful payload operation with pr_err(), which made normal
traffic too noisy.

Keep only negotiation, RDMA READ preparation, RDMA WRITE transform
metadata, crypto completion, and final transfer completion messages as
KSMBD_DEBUG_RDMA diagnostics. Keep error reports for malformed metadata,
crypto, RDMA transfer, and file write failures at error level.

This preserves the diagnostics needed to verify RDMA transform
operation without flooding the kernel error log during normal I/O.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:26 +09:00
Namjae Jeon
05c978948e ksmbd: add SMB Direct RDMA encryption transform
Port SMB Direct RDMA payload encryption support to the current ksmbd tree.
The current tree already supports all-state lookup for encrypted expired
sessions, so the overlapping lookup hunk from the original patch is
intentionally omitted.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:25 +09:00
Namjae Jeon
6639b6928b ksmbd: handle encrypted compressed requests
SMB3 permits a message to be compressed before it is encrypted. After
decrypting such a request, ksmbd must trim the AEAD tag using
OriginalMessageSize, decompress the nested compression transform, and
validate the resulting SMB2 PDU.

Share the decompression helper between the connection receive path and
the post-decryption work path so unencrypted and encrypted compressed
requests follow the same validation.

Fixes: a08de24c2b ("ksmbd: negotiate and decode SMB2 compression")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:25 +09:00
Namjae Jeon
d8fc4fc7e5 ksmbd: decrypt requests from expired encrypted sessions
Previous-session replacement marks the old session expired but retains its
SMB3 encryption key. An in-flight encrypted request can still arrive on
that connection. Rejecting the expired session before decryption made ksmbd
treat the request as a key failure and abort the transport, causing
reconnect failures.

Allow key lookup for expired sessions that have encryption enabled. Keep
the session reference during validation so the normal
STATUS_USER_SESSION_DELETED response is encrypted with the old key. The
session remains expired and no command is executed.

Fixes: fa9415d402 ("ksmbd: mark SMB2_SESSION_EXPIRED to session when destroying previous session")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:25 +09:00
Namjae Jeon
12a6680ce5 ksmbd: disconnect on SMB3 decryption failure
MS-SMB2 requires the server to disconnect a connection when an
encrypted transform cannot be associated with a session or fails
authenticated decryption. This includes an encrypted request that
still carries a SessionId invalidated through PreviousSessionId.

Move the connection to EXITING and shut down its transport when
decrypt_req() fails. Add the missing TCP shutdown callback so a receive
blocked in kernel_recvmsg() is released; SMB Direct already provides
the corresponding callback.

Plaintext requests using an invalidated SessionId do not take this
path and continue to receive STATUS_USER_SESSION_DELETED.

Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:25 +09:00
Namjae Jeon
2a0e037648 ksmbd: encrypt interim responses to encrypted requests
The normal response path applies an SMB3 transform when the request was
encrypted.  Async interim responses, completed compound prefixes and two
CHANGE_NOTIFY cleanup paths write their synthetic response work directly,
bypassing that encryption step.

A packet capture shows FE SMB2 STATUS_PENDING, CREATE and CHANGE_NOTIFY
responses following FD SMB3 requests.  The client resets the connection
immediately after receiving those plaintext responses.

Send synthetic interim work through a common helper that applies the
session encryption transform first.  A compound prefix shares the original
work's response iov, which encryption would replace in place, so flatten it
into an independently owned work before encrypting and sending it.

Fixes: 64bfa9d49026 ("smb/server: use MSG_EOR for async interim response")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:24 +09:00
Namjae Jeon
c50e628122 ksmbd: scope session state changes to bound connections
ksmbd_all_conn_set_status() treats every connection whose transient
binding flag is set as belonging to the target SessionId.  A logoff or
session replacement can consequently move an unrelated connection to
NEED_RECONNECT or NEED_SETUP.

Pass the target session itself and select connections using either the
connection-local session xarray or the session's permanent channel list.
Use the same association test while waiting for requests to drain.

Serialize session-wide status changes under request_lock and do not
overwrite EXITING or RELEASING. Protect the shutdown transition with the
same lock so a concurrent session update cannot revive a closing
connection.

Fixes: f5a544e3ba ("ksmbd: add support for SMB3 multichannel")
Fixes: abcc506a9a ("ksmbd: fix racy issue from smb2 close and logoff with multichannel")
Fixes: c444139cb7 ("ksmbd: rewrite stop_sessions() with restartable iteration")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:24 +09:00
Namjae Jeon
2cbd4a8bf4 ksmbd: fix encrypted request lookup on bound channels
An SMB3 multichannel binding registers the secondary connection in the
session channel list, but does not insert the session into the secondary
connection's session xarray.

The decryption path only searches the connection-local xarray.  As a
result, every encrypted request received on a bound channel fails with
"Could not get decryption key".

Use the channel-aware session lookup for decryption.  Also stop using the
temporary conn->binding flag to decide whether the global lookup is
allowed.  Validate the permanent channel association under chann_lock
instead.

Fixes: f5a544e3ba ("ksmbd: add support for SMB3 multichannel")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:24 +09:00
Namjae Jeon
50a400cff5 ksmbd: add per-share SMB3 encryption enforcement
Add a share flag for requiring SMB3 encryption on an individual share.

Advertise SMB2_SHAREFLAG_ENCRYPT_DATA in TREE_CONNECT responses and
reject both unencrypted TREE_CONNECT attempts and plaintext requests for
shares carrying the flag.

Keep BIT(19) reserved for the existing ksmbd-tools WIDE_LINKS flag and
use BIT(20) for the new netlink ABI flag.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:24 +09:00
Namjae Jeon
abe5acb342 ksmbd: notify parent directory leases on child create
BVT_DirectoryLeasing_ReadWriteHandleCaching requires a parent directory
lease break notification when another client creates a child in the
leased directory. A child CREATE without a lease context did not notify
the parent lease holders because the notification path expected a
non-NULL lease context.

Allow the parent lease notification helper to handle a NULL child lease
context and notify matching parent leases. Invoke it after a child is
created without a lease context while preserving the existing lease-key
filtering for requests that provide one.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:24 +09:00
Namjae Jeon
5213c36863 ksmbd: implement SMB2 AppInstanceVersion takeover
BVT_AppInstanceVersion_SMB311_GreaterVersion,
BVT_AppInstanceVersion_SMB311_SameVersion,
BVT_AppInstanceVersion_SMB311_LowerAppInstanceVersionHigh, and
BVT_AppInstanceVersion_SMB311_LowerAppInstanceVersionLow exercise
ordered opens using the same AppInstanceId. ksmbd tracked the
AppInstanceId, but did not parse the version context or enforce the
version ordering, so versioned opens returned incorrect sharing
violations.

Parse and retain the 24-byte AppInstanceVersion context with each open.
Reject a version that is lower than or equal to the active version with
STATUS_FILE_FORCED_CLOSED, reject an unversioned open against a versioned
handle, and close the previous handle for a newer takeover. Do not apply
the takeover check to durable reconnect or replay requests.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:23 +09:00
Namjae Jeon
68f3508e4c ksmbd: accept unspecified volatile ID on durable reconnect
BVT_DurableHandleV1_Reconnect_WithBatchOplock,
BVT_DurableHandleV1_Reconnect_WithLeaseV1,
BVT_DurableHandleV2_Reconnect_WithBatchOplock, and
BVT_DurableHandleV2_Reconnect_WithLeaseV1 fail to reconnect a durable
handle when the request leaves VolatileFileId unset.

A durable reconnect request may omit VolatileFileId by setting it to
zero. Treating zero as an ID makes ksmbd reject the request whenever the
saved volatile ID is nonzero.

Only compare the saved and requested volatile IDs when the request
contains a nonzero value. Explicit mismatches continue to be rejected.

This allows SMB2 durable handle V1 and V2 reconnects that identify the
handle through the persistent ID and reconnect context.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:23 +09:00
Ze Tan
39f2032096 smb/server: fix tree connection leak in smb2_tree_connect()
See the procedure below:

  smb2_tree_connect
    ksmbd_tree_conn_connect
      xa_store(&sess->tree_conns, tree_conn->id, tree_conn)
      ksmbd_counter_inc(KSMBD_COUNTER_TREE_CONNS)
      ksmbd_share_tree_conn_inc(sc)
    ksmbd_iov_pin_rsp // fail
    status.ret = KSMBD_TREE_CONN_STATUS_NOMEM
    // do not disconnect tree_conn

Disconnect the new tree connection if ksmbd_iov_pin_rsp() fails.

Fixes: e2b76ab8b5 ("ksmbd: add support for read compound")
Signed-off-by: Ze Tan <tanze@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:23 +09:00
Namjae Jeon
4818df5aaa ksmbd: wait for deferred notify cancellation
A cancelled SMB2 CHANGE_NOTIFY request is completed from system_wq. The
deferred work keeps a reference to the connection, but it is not included
in the connection's r_count. During connection teardown,
ksmbd_conn_transport_destroy() can therefore finish the connection handler
and destroy session proc entries before the deferred response runs.

Account for the deferred cancellation work in r_count. The connection
handler now waits for the deferred response to finish before it
deregisters sessions and removes their proc entries.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:22 +09:00
ChenXiaoSong
93a3cda161 smb/server: fix use-after-free in ksmbd_conn_transport_destroy()
Reproducer (Link[1]):

  1. Build kernel with CONFIG_KASAN=y
  2. server: systemctl start ksmbd
  3. client: mount -t cifs //localhost/export /mnt
  4. client: umount /mnt
  5. server: modprobe -r ksmbd

The error message is as follows:

  ==================================================================
  BUG: KASAN: slab-use-after-free in proc_remove+0x3e/0x80
  Read of size 8 at addr ffff88810654e098 by task modprobe/785
  ...
  Call Trace:
   <TASK>
   __dump_stack+0x19/0x30
   dump_stack_lvl+0x49/0x60
   print_address_description+0x7b/0x200
   print_report+0x5b/0x70
   kasan_report+0xed/0x130
   __asan_report_load8_noabort+0x18/0x20
   proc_remove+0x3e/0x80
   ksmbd_conn_transport_destroy+0x2b/0x320 [ksmbd]
   cleanup_module+0x33/0xe00 [ksmbd]
   __se_sys_delete_module+0x276/0x400
   __x64_sys_delete_module+0x5f/0x70
   x64_sys_call+0x2675/0x3030
   do_syscall_64+0xf0/0x3b0
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f5b56d2b02b
  ...
   </TASK>

  Allocated by task 159:
   kasan_save_track+0x2f/0x70
   kasan_save_alloc_info+0x40/0x50
   __kasan_slab_alloc+0x52/0x70
   kmem_cache_alloc_noprof+0x168/0x3e0
   __proc_create+0x20b/0x710
   proc_create_single_data+0x78/0x150
   ksmbd_proc_create+0x24/0x30 [ksmbd]
   ksmbd_conn_transport_init+0x4f/0x80 [ksmbd]
   server_ctrl_handle_work+0x64/0x2c0 [ksmbd]
   process_scheduled_works+0x788/0xec0
   worker_thread+0x894/0xc10
   kthread+0x2e5/0x3c0
   ret_from_fork+0x168/0x4f0
   ret_from_fork_asm+0x1a/0x30

  Freed by task 785:
   kasan_save_track+0x2f/0x70
   kasan_save_free_info+0x4a/0x60
   __kasan_slab_free+0x47/0x70
   kmem_cache_free+0x122/0x410
   pde_put+0xfd/0x160
   remove_proc_subtree+0x365/0x540
   proc_remove+0x6a/0x80
   ksmbd_proc_cleanup+0x1f/0x60 [ksmbd]
   cleanup_module+0x18/0xe00 [ksmbd]
   __se_sys_delete_module+0x276/0x400
   __x64_sys_delete_module+0x5f/0x70
   x64_sys_call+0x2675/0x3030
   do_syscall_64+0xf0/0x3b0
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  ==================================================================

Reported-by: Kyenghwan Hwang <obnred@gmail.com>
Link[1]: https://lore.kernel.org/linux-cifs/8ea028f5-90f4-4d21-b1ac-a343f0f04d88@chenxiaosong.com/
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:22 +09:00
Namjae Jeon
215e8816b1 ksmbd: detach blocked lock requests before freeing
A file_lock retained by ksmbd for byte-range lock bookkeeping can still
be part of the VFS blocked-request graph. In particular, the VFS can
chain a new waiter below an already blocked request through
flc_blocked_requests. The ksmbd_file reference count does not cover that
graph.

Both __ksmbd_close_fd() and the cross-request unlock path free these
retained file_lock objects directly. If a dependent waiter is still
attached, locks_release_private() hits
BUG_ON(!list_empty(&flc->flc_blocked_requests)). The same lifetime
mismatch can leave a freed ksmbd_lock reachable through its request-local
llist.

Detach the file_lock from the blocked-request graph before freeing it in
the close, cross-request unlock, and rollback paths. locks_delete_block()
also wakes requests chained below the object. Remove llist when a
completed lock is published so a globally visible ksmbd_lock no longer
points into the submitting worker's stack.

Fixes: d63528eb0d ("ksmbd: free ksmbd_lock when file is closed")
Reported-by: Kyenghwan Hwang <obnred@gmail.com>
Tested-by: Kyenghwan Hwang <obnred@gmail.com>
Tested-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:22 +09:00
Thomas Huth
5b90f78dc2 smb: server: Clear Preauth_HashValue in smb2pdu.c with kfree_sensitive()
struct preauth_session contains the Preauth_HashValue[] array that
might contain sensitive data. Use kfree_sensitive() to clear it
before returning the memory to the heap.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:22 +09:00
Thomas Huth
0cb81ed8b5 smb: server: Free sensitive data in connection.c with kfree_sensitive()
struct ksmbd_conn contains an embedded struct ntlmssp_auth with the
ciphertext[] and cryptkey[] arrays, so to avoid leaking this information
via the heap, it should be freed with kfree_sensitive().

While we're at it, also use kfree_sensitive() for freeing preauth_info
in ksmbd_conn_free() to avoid that the Preauth_HashValue[] could leak
via the heap here, too.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:22 +09:00
Thomas Huth
9a4bd6507c smb: server: Free session data in user_session.c with kfree_sensitive()
struct ksmbd_session contains some arrays with sensitive information, like
sess_key, smb3encryptionkey, smb3decryptionkey and smb3signingkey. Thus
let's make sure that this information cannot leak via the heap and use
kfree_sensitive() to free it.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:21 +09:00
Thomas Huth
2c5a176882 smb: server: Make sure that passkey is not leaked on the heap in user_config.c
Use kfree_sensitive() to free the user->passkey (and the struct
ksmbd_login_response in ksmbd_login_user() that contains the same
information) to avoid that this information could leak somewhere
else via the heap.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17 22:38:21 +09:00