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path: root/fs/smb/server/connection.c
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2026-08-31ksmbd: safely drain sessions during logoffNamjae Jeon1-2/+6
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: 76e98a158b20 ("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>
2026-08-17smb/server: warn if ksmbd_proc_create() failsZe Tan1-1/+2
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>
2026-08-17ksmbd: add SMB Direct RDMA encryption transformNamjae Jeon1-0/+2
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>
2026-08-17ksmbd: disconnect on SMB3 decryption failureNamjae Jeon1-0/+16
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: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17ksmbd: scope session state changes to bound connectionsNamjae Jeon1-6/+31
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: f5a544e3bab7 ("ksmbd: add support for SMB3 multichannel") Fixes: abcc506a9a71 ("ksmbd: fix racy issue from smb2 close and logoff with multichannel") Fixes: c444139cb747 ("ksmbd: rewrite stop_sessions() with restartable iteration") Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17smb: server: Free sensitive data in connection.c with kfree_sensitive()Thomas Huth1-3/+3
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>
2026-08-17ksmbd: free preauth sessions on connection teardownNamjae Jeon1-0/+3
SMB3.1.1 multichannel binding preserves the preauthentication hash in a preauth_session between the NTLM negotiate and authenticate requests. The binding NTLM negotiate allocates this object and returns STATUS_MORE_PROCESSING_REQUIRED. If the client disconnects before it sends the authenticate request, neither the authenticate nor error cleanup paths free the object. Release any remaining preauthentication sessions when tearing down the connection. Initialize the list when allocating the connection so that this cleanup is safe regardless of the negotiated dialect. Reported-by: Runa Takemoto <takemotoruna223@gmail.com> Fixes: f5a544e3bab7 ("ksmbd: add support for SMB3 multichannel") Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17smb/server: cancel async requests when closing connectionChenXiaoSong1-0/+21
An async request may still be waiting when a connection is closed. This can stop the connection from closing. Cancel active async requests before waiting for them to finish. Suggested-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17ksmbd: implement the command sequence windowNamjae Jeon1-0/+8
ksmbd tracked only credit counts (total_credits/outstanding_credits) and never validated the MessageId of an incoming request. As a result a request carrying a MessageId outside the granted range was accepted, a MessageId could be replayed, and a 64-bit sequence wrap was not detected. Maintain a command sequence window per connection: - [seq_low, seq_high) is the range of granted sequence numbers and seq_bitmap records which of them have been granted but not yet consumed. The window starts as { 0 } at connection setup. - smb2_set_rsp_credits() extends seq_high by the number of credits it grants (setting the corresponding bits), capped so the window never spans more than KSMBD_CMD_SEQ_WINDOW (== SMB2_MAX_CREDITS) sequence numbers. This implements the "limit the range of acceptable sequence numbers" allowance and keeps seq_bitmap usable as a ring. - smb2_check_sequence_number(), run for every SMB2 request from ksmbd_smb2_check_message(), verifies that the CreditCharge consecutive sequence numbers starting at MessageId lie within the window and have not already been consumed, then removes them and slides seq_low forward. CANCEL consumes nothing. A violation (out of window, replay, or wrap) tears the connection down. The legacy SMB1 multi-protocol negotiate occupies sequence number 0 but does not pass through ksmbd_smb2_check_message(), so it consumes that sequence number explicitly; otherwise seq_low would stay pinned at 0 after the upgrade to SMB2 and eventually stall credit grants. For an in-order client seq_high - seq_low equals total_credits, so the window-room cap never reduces the number of credits granted. it only engages for a client that withholds low sequence numbers. init_smb2_max_credits() now clamps the configured maximum to SMB2_MAX_CREDITS so the window (and its bitmap) can always represent every outstanding sequence number. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17ksmbd: expose connection runtime state in procfsNamjae Jeon1-12/+84
The clients proc file currently shows only a small subset of the state needed to diagnose stalled or mis-negotiated connections. Report the transport, connection state, outstanding and total credits, session count, lifetime request count, and negotiated signing, encryption, compression, and POSIX features. Report each connection as a key/value record rather than a wide fixed-width table. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17ksmbd: fix malformed procfs status outputNamjae Jeon1-6/+6
The ksmbd procfs monitoring files produce misleading or malformed output. The constant-name helper uses a bitwise test for enum values. This omits zero-valued constants and can print multiple names for one lease state. It also unconditionally emits a newline, splitting entries in the open-file table across two lines. Session capabilities are printed as numeric flag values even though a table of descriptive names is available. Use exact matching for enum values. Print flag names as a comma-separated list, preserving unknown bits as hexadecimal values. Let callers control line termination so each open-file entry remains on one line. Print common session properties once, and report signing and encryption independently. Adjust client and open-file column widths for IPv6 addresses and 64-bit file IDs, and fix the misspelled OPLOCK_EXCLUSIVE name. Also expose and maintain the total request count alongside the per-command counters. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17smb/server: use MSG_EOR for async interim responseChenXiaoSong1-0/+9
Two kernel_sendmsg() calls can still use the same TCP skb if the first skb can take more data. This can happen when ksmbd sends two SMB2 responses very close to each other. Without MSG_EOR, TCP can append the next sendmsg data to the previous skb. Then STATUS_PENDING and the later response can be put into the same TCP skb. MSG_EOR marks the skb as end of record, so TCP will not collapse the next sendmsg data into it. Example: smbtorture //${server_ip}/export -U${username}%${password} smb2.compound_async.write_write Client request: Write Request Len:64 Off:0, File: compound_async_write_write; Write Request Len:64 Off:64 Before this patch, server responses: Write Response, File: compound_async_write_write Write Response SMB2, STATUS_PENDING, Write Response, MessageId 7 SMB2, Write Response, MessageId 7 After this patch: Write Response, File: compound_async_write_write Write Response, Error: STATUS_PENDING Write Response Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17smb/server: introduce struct ksmbd_transport_writeChenXiaoSong1-6/+16
Put the arguments of ksmbd_transport_ops ->writev() into a struct. This makes the function call shorter and easier to read. Add __ksmbd_conn_write() for the common write code. A later patch will use it for another write helper. No functional change. Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-03ksmbd: apply the pre-authentication PDU limit when decompressingSujal Tuladhar1-5/+1
ksmbd_conn_handler_loop() caps a request from an unauthenticated connection at SMB3_MAX_MSGSIZE, and only allows the larger SMB3_MAX_MSGSIZE + conn->vals->max_write_size once the connection has authenticated. ksmbd_decompress_request() runs inside that same loop but applies the authenticated limit unconditionally, and then allocates from it. The unauthenticated cap is not re-applied afterwards, as the caller only refreshes pdu_size from the new RFC1002 header. An unauthenticated client that negotiates SMB 3.1.1 with a compression context can therefore send a 104 byte chained transform whose OriginalCompressedSegmentSize is SMB3_MAX_MSGSIZE + max_write_size and have ksmbd kvmalloc() that much memory, 4210693 bytes by default. The payload costs the client nothing, because a SMB3_COMPRESS_PATTERN payload expands an eight byte structure into arbitrarily many output bytes. The decompressed PDU is rejected later by ksmbd_smb2_check_message(), but that happens in the worker, after the allocation has been made and conn->req_running has been incremented, and it results in an error response rather than dropping the connection. A client that stops reading its socket keeps each work queued for up to KSMBD_TCP_SEND_TIMEOUT while ksmbd_conn_write() holds conn->srv_mutex, so the allocations accumulate up to server_conf.max_inflight_req per connection. Move the limit into ksmbd_max_allowed_pdu_size() and call it from both sites, so the authentication state is consulted in one place and the two ceilings cannot drift apart again. Fixes: a08de24c2b85 ("ksmbd: negotiate and decode SMB2 compression") Signed-off-by: Sujal Tuladhar <sujaltuladhar1231@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-22ksmbd: validate minimum PDU size for transform requestsNamjae Jeon1-5/+11
The receive path applies the minimum SMB2 PDU size check only when ProtocolId is SMB2_PROTO_NUMBER. A packet carrying SMB2_TRANSFORM_PROTO_NUM bypasses the check even when the negotiated dialect does not provide transform handling. On an SMB 2.1 connection, a short transform packet therefore reaches init_smb2_rsp_hdr(), which interprets the request as a full SMB2 header and reads beyond the request allocation. The copied fields can then be returned to the unauthenticated client. Compression transforms are converted to ordinary SMB2 messages before protocol validation. After that conversion, validate ordinary SMB2 requests against SMB2_MIN_SUPPORTED_PDU_SIZE and require encryption transform requests to contain both a transform header and an SMB2 header. This rejects truncated requests before work allocation. Fixes: 368ba06881c3 ("ksmbd: check the validation of pdu_size in ksmbd_conn_handler_loop") Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-31063 Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-06-16ksmbd: negotiate and decode SMB2 compressionNamjae Jeon1-0/+12
Parse the SMB 3.1.1 compression capabilities context and negotiate LZ77 with optional chained Pattern_V1 support. Advertise compression on tree connections and decode compressed requests before normal SMB dispatch. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-05-01ksmbd: fix kernel-doc warnings from ksmbd_conn_get/put()Namjae Jeon1-0/+4
The kernel test robot reported W=1 build warnings for ksmbd_conn_get() and ksmbd_conn_put() due to missing parameter descriptions. Add the @conn description to fix these warnings. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-05-01ksmbd: centralize ksmbd_conn final release to plug transport leakDaeMyung Kang1-15/+86
ksmbd_conn_free() is one of four sites that can observe the last refcount drop of a struct ksmbd_conn. The other three fs/smb/server/connection.c ksmbd_conn_r_count_dec() fs/smb/server/oplock.c __free_opinfo() fs/smb/server/vfs_cache.c session_fd_check() end the conn with a bare kfree(), skipping ida_destroy(&conn->async_ida) and conn->transport->ops->free_transport(conn->transport). Whenever one of them is the last putter, the embedded async_ida and the entire transport struct leak -- for TCP, that is also the struct socket and the kvec iov. __free_opinfo() being a final putter is not theoretical. opinfo_put() queues the callback via call_rcu(&opinfo->rcu, free_opinfo_rcu), so ksmbd_server_terminate_conn() can deposit N opinfo releases in RCU and have ksmbd_conn_free() run in the handler thread before any of them fire. ksmbd_conn_free() then observes refcnt > 0 and short-circuits; the last RCU-delivered __free_opinfo() falls onto its bare kfree(conn) branch and the transport is lost. A/B validation in a QEMU/virtme guest, mounting //127.0.0.1/testshare: each iteration holds 8 files open via sleep processes, force-closes TCP with "ss -K sport = :445", kills the holders, lazy-umounts; repeated 10 times, then ksmbd shutdown and kmemleak scan. state conn_alloc conn_free tcp_free opi_rcu kmemleak ---------- ---------- --------- -------- ------- -------- pre-patch 20 20 10 160 7 with patch 20 20 20 160 0 Pre-patch conn_free=20 with tcp_free=10 directly demonstrates the bare-kfree paths skipping transport cleanup; kmemleak backtraces point into struct tcp_transport / iov. With this patch tcp_free matches conn_free at 20/20 and kmemleak is clean. Move the per-struct final release into __ksmbd_conn_release_work() and route the three bare-kfree final-put sites through a new ksmbd_conn_put(). Those sites now pair ida_destroy() and free_transport() with kfree(conn) regardless of which holder happens to release the last reference. stop_sessions() only triggers the transport shutdown and does not itself drop the last conn reference, so it is unaffected. The centralized release reaches sock_release() -> tcp_close() -> lock_sock_nested() (might_sleep) from every final putter, including __free_opinfo() invoked from an RCU softirq callback, which trips CONFIG_DEBUG_ATOMIC_SLEEP. Defer the release to a dedicated ksmbd_conn_wq workqueue so ksmbd_conn_put() is safe from any non-sleeping context. Make ksmbd_file own a strong connection reference while fp->conn is non-NULL so durable-preserve and final-close paths cannot dereference a stale connection. ksmbd_open_fd() and ksmbd_reopen_durable_fd() take the reference via ksmbd_conn_get() (the latter also reorders the fp->conn / fp->tcon assignments before __open_id() so the published fp is never observed with fp->conn == NULL); session_fd_check() and __ksmbd_close_fd() drop it via ksmbd_conn_put(). With that invariant, session_fd_check() can take a local conn pointer once and use it across the m_op_list and lock_list iterations even though op->conn puts may otherwise drop the last reference. At module exit the workqueue is flushed and destroyed after rcu_barrier(), so any release queued by a trailing RCU callback is drained before the inode hash and module text go away. Fixes: ee426bfb9d09 ("ksmbd: add refcnt to ksmbd_conn struct") Signed-off-by: DaeMyung Kang <charsyam@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-04-29ksmbd: rewrite stop_sessions() with restartable iterationDaeMyung Kang1-8/+38
stop_sessions() walks conn_list with hash_for_each() and, for every entry, drops conn_list_lock across the transport ->shutdown() call before re-acquiring the read lock to continue the loop. The hash walk relies on cross-iteration state (the current bucket and the hlist position), which is not preserved across unlock/relock: if another thread performs a list mutation during the unlocked window, the ongoing iteration becomes unreliable and can re-visit connections that have already been handled or skip connections that have not. The outer `if (!hash_empty(conn_list)) goto again;` retry masks the symptom in the common case but does not address the unsafe iteration itself. Reframe the loop so it never relies on iterator state across unlock/relock. Under conn_list_lock held for read, pick the first connection whose ->shutdown() has not yet been issued by this path, pin it by taking an extra reference, record that fact on the connection and mark it EXITING while still inside the locked walk, then drop the lock. Then call ->shutdown() outside the lock, drop the pin (freeing the connection if the handler already released its reference), and restart from the top. Use a new per-connection flag, conn->stop_called, as the "shutdown issued from stop_sessions()" marker rather than reusing the status state. ksmbd_conn_set_exiting() is also invoked by ksmbd_sessions_deregister() on sibling channels of a multichannel session without issuing a transport shutdown, so treating KSMBD_SESS_EXITING as "already handled here" would skip connections that still need shutdown() to wake their handler out of recv(), leaving the outer retry waiting indefinitely for the hash to drain. stop_sessions() is serialised by init_lock in ksmbd_conn_transport_destroy(), so writing stop_called under the read lock has no other writer. Set EXITING inside the locked walk so the selection, the stop_called marker, and the status transition all happen together, and guard against regressing a connection that has already advanced to KSMBD_SESS_RELEASING on its own (for example, if the handler exited its receive loop for an unrelated reason between teardown steps). When the pin drop is the last put, release the transport and pair ida_destroy(&target->async_ida) with the ida_init() done in ksmbd_conn_alloc(), so stop_sessions() retiring a connection on its own does not leak the xarray backing of the embedded async_ida. The outer retry with msleep() is kept to wait for handler threads to reach ksmbd_conn_free() and drain the hash. Observed with an instrumented build that logs one line per visit and widens the unlocked window before ->shutdown() by 200 ms, under five concurrent cifs mounts (nosharesock, one connection each): * Current code: the same connection address is revisited many times during a single stop_sessions() call and ->shutdown() is invoked well beyond the number of live connections before the hash finally drains. * Rewritten code: each live connection produces exactly one ->shutdown() call; the function returns as soon as the hash is empty. Functional teardown via `ksmbd.control --shutdown` with the same five mounts completes cleanly on the rewritten path. Performance is observably unchanged. Tearing down N concurrent nosharesock cifs connections with `ksmbd.control --shutdown` + `rmmod ksmbd` takes essentially the same wall time before and after the rewrite: N before after 10 4.93s 5.34s 30 7.34s 7.03s 50 7.31s 7.01s (3-run avg: 7.04s vs 7.25s) 100 6.98s 6.78s 200 6.77s 6.89s and the number of ->shutdown() calls equals the number of live connections on both paths when the race is not widened. The teardown is dominated by the msleep(100)-based outer retry waiting for handler threads to run ksmbd_conn_free(), not by the iteration itself; the restartable loop's worst-case O(N^2) visit cost is in the microseconds even at N=200 and sits far below the msleep(100) granularity. Applied alone on top of ksmbd-for-next-next, this patch does not introduce a new leak site. Under the same reproducer (10x concurrent-holders + ss -K + ksmbd.control --shutdown + rmmod), the tree still shows the pre-existing per-connection transport leak count that arises when the last refcount drop lands in one of ksmbd_conn_r_count_dec(), __free_opinfo() or session_fd_check() - all of which end with a bare kfree() today. kmemleak backtraces for the unreferenced objects point into the TCP accept path (sk_clone -> inet_csk_clone_lock, sock_alloc_inode) and none involve stop_sessions(). Plugging those bare-kfree sites is the responsibility of the follow-up patch. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Signed-off-by: DaeMyung Kang <charsyam@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-04-22ksmbd: destroy async_ida in ksmbd_conn_free()DaeMyung Kang1-0/+9
When per-connection async_ida was converted from a dynamically allocated ksmbd_ida to an embedded struct ida, ksmbd_ida_free() was removed from the connection teardown path but no matching ida_destroy() was added. The connection is therefore freed with the IDA's backing xarray still intact. The kernel IDA API expects ida_init() and ida_destroy() to be paired over an object's lifetime, so add the missing cleanup before the connection is freed. No leak has been observed in testing; this is a pairing fix to match the IDA lifetime rules, not a response to a reproduced regression. Fixes: d40012a83f87 ("cifsd: declare ida statically") Signed-off-by: DaeMyung Kang <charsyam@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-04-22ksmbd: reset rcount per connection in ksmbd_conn_wait_idle_sess_id()DaeMyung Kang1-3/+2
rcount is intended to be connection-specific: 2 for curr_conn, 1 for every other connection sharing the same session. However, it is initialised only once before the hash iteration and is never reset. After the loop visits curr_conn, later sibling connections are also checked against rcount == 2, so a sibling with req_running == 1 is incorrectly treated as idle. This makes the outcome depend on the hash iteration order: whether a given sibling is checked against the loose (< 2) or the strict (< 1) threshold is decided by whether it happens to be visited before or after curr_conn. The function's contract is "wait until every connection sharing this session is idle" so that destroy_previous_session() can safely tear the session down. The latched rcount violates that contract and reopens the teardown race window the wait logic was meant to close: destroy_previous_session() may proceed before sibling channels have actually quiesced, overlapping session teardown with in-flight work on those connections. Recompute rcount inside the loop so each connection is compared against its own threshold regardless of iteration order. This is a code-inspection fix for an iteration-order-dependent logic error; a targeted reproducer would require SMB3 multichannel with in-flight work on a sibling channel landing after curr_conn in hash order, which is not something that can be triggered reliably. Fixes: 76e98a158b20 ("ksmbd: fix race condition between destroy_previous_session() and smb2 operations()") Cc: stable@vger.kernel.org Signed-off-by: DaeMyung Kang <charsyam@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-04-15smb: server: no longer use smbdirect_socket_set_custom_workqueue()Stefan Metzmacher1-1/+0
smbdirect.ko has global workqueues now, so we should use these default once. Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: Steve French <smfrench@gmail.com> Cc: Tom Talpey <tom@talpey.com> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Signed-off-by: Stefan Metzmacher <metze@samba.org> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-04-15smb: server: remove unused ksmbd_transport_ops.prepare()Stefan Metzmacher1-4/+0
This is no longer needed for smbdirect. Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: Steve French <smfrench@gmail.com> Cc: Tom Talpey <tom@talpey.com> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Signed-off-by: Stefan Metzmacher <metze@samba.org> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-04-12ksmbd: fix mechToken leak when SPNEGO decode fails after token allocGreg Kroah-Hartman1-0/+1
The kernel ASN.1 BER decoder calls action callbacks incrementally as it walks the input. When ksmbd_decode_negTokenInit() reaches the mechToken [2] OCTET STRING element, ksmbd_neg_token_alloc() allocates conn->mechToken immediately via kmemdup_nul(). If a later element in the same blob is malformed, then the decoder will return nonzero after the allocation is already live. This could happen if mechListMIC [3] overrunse the enclosing SEQUENCE. decode_negotiation_token() then sets conn->use_spnego = false because both the negTokenInit and negTokenTarg grammars failed. The cleanup at the bottom of smb2_sess_setup() is gated on use_spnego: if (conn->use_spnego && conn->mechToken) { kfree(conn->mechToken); conn->mechToken = NULL; } so the kfree is skipped, causing the mechToken to never be freed. This codepath is reachable pre-authentication, so untrusted clients can cause slow memory leaks on a server without even being properly authenticated. Fix this up by not checking check for use_spnego, as it's not required, so the memory will always be properly freed. At the same time, always free the memory in ksmbd_conn_free() incase some other failure path forgot to free it. Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: Steve French <smfrench@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Tom Talpey <tom@talpey.com> Cc: linux-cifs@vger.kernel.org Cc: <stable@kernel.org> Assisted-by: gregkh_clanker_t1000 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook1-1/+1
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-10ksmbd: fix non-IPv6 buildArnd Bergmann1-3/+5
The newly added procfs code fails to build when CONFIG_IPv6 is disabled: fs/smb/server/connection.c: In function 'proc_show_clients': fs/smb/server/connection.c:47:58: error: 'struct ksmbd_conn' has no member named 'inet6_addr'; did you mean 'inet_addr'? 47 | seq_printf(m, "%-20pI6c", &conn->inet6_addr); | ^~~~~~~~~~ | inet_addr make[7]: *** [scripts/Makefile.build:279: fs/smb/server/connection.o] Error 1 fs/smb/server/mgmt/user_session.c: In function 'show_proc_sessions': fs/smb/server/mgmt/user_session.c:215:65: error: 'struct ksmbd_conn' has no member named 'inet6_addr'; did you mean 'inet_addr'? 215 | seq_printf(m, " %-40pI6c", &chan->conn->inet6_addr); | ^~~~~~~~~~ | inet_addr Rearrange the condition to allow adding a simple preprocessor conditional. Fixes: b38f99c1217a ("ksmbd: add procfs interface for runtime monitoring and statistics") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-02-08ksmbd: add procfs interface for runtime monitoring and statisticsBahubali B Gumaji1-0/+57
This patch introduces a /proc filesystem interface to ksmbd, providing visibility into the internal state of the SMB server. This allows administrators and developers to monitor active connections, user sessions, and opened files in real-time without relying on external tools or heavy debugging. Key changes include: - Connection Monitoring (/proc/fs/ksmbd/clients): Displays a list of active network connections, including client IP addresses, SMB dialects, credits, and last active timestamps. - Session Management (/proc/fs/ksmbd/sessions/): Adds a global sessions file to list all authenticated users and their session IDs. - Creates individual session entries (e.g., /proc/fs/ksmbd/sessions/<id>) detailing capabilities (DFS, Multi-channel, etc.), signing/encryption algorithms, and connected tree shares. - File Tracking (/proc/fs/ksmbd/files): Shows all currently opened files across the server, including tree IDs, process IDs (PID), access modes (daccess/saccess), and oplock/lease states. - Statistics & Counters: Implements internal counters for global server metrics, such as the number of tree connections, total sessions, and processed read/write bytes. Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com> Signed-off-by: Bahubali B Gumaji <bahubali.bg@samsung.com> Signed-off-by: Sang-Soo Lee <constant.lee@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-12-21smb/server: fix minimum SMB2 PDU sizeChenXiaoSong1-2/+2
The minimum SMB2 PDU size should be updated to the size of `struct smb2_pdu` (that is, the size of `struct smb2_hdr` + 2). Suggested-by: David Howells <dhowells@redhat.com> Suggested-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-12-21smb/server: fix minimum SMB1 PDU sizeChenXiaoSong1-2/+3
Since the RFC1002 header has been removed from `struct smb_hdr`, the minimum SMB1 PDU size should be updated as well. Fixes: 83bfbd0bb902 ("cifs: Remove the RFC1002 header from smb_hdr") Suggested-by: David Howells <dhowells@redhat.com> Suggested-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-12-21ksmbd: rename smb2_get_msg to smb_get_msgNamjae Jeon1-1/+1
With the removal of the RFC1002 length field from the SMB header, smb2_get_msg is now used to get the smb1 request from the request buffer. Since this function is no longer exclusive to smb2 and now supports smb1 as well, This patch rename it to smb_get_msg to better reflect its usage. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-09-30ksmbd: replace connection list with hash tableNamjae Jeon1-12/+11
Replace connection list with hash table to improve lookup performance. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-09-28smb: server: make use of common smbdirect.hStefan Metzmacher1-2/+2
Cc: Steve French <smfrench@gmail.com> Cc: Tom Talpey <tom@talpey.com> Cc: Long Li <longli@microsoft.com> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: Hyunchul Lee <hyc.lee@gmail.com> Cc: Meetakshi Setiya <meetakshisetiyaoss@gmail.com> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Signed-off-by: Stefan Metzmacher <metze@samba.org> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-08-17smb: server: split ksmbd_rdma_stop_listening() out of ksmbd_rdma_destroy()Stefan Metzmacher1-1/+2
We can't call destroy_workqueue(smb_direct_wq); before stop_sessions()! Otherwise already existing connections try to use smb_direct_wq as a NULL pointer. Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: Steve French <smfrench@gmail.com> Cc: Tom Talpey <tom@talpey.com> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and tranport layers") Signed-off-by: Stefan Metzmacher <metze@samba.org> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-06-17ksmbd: add free_transport ops in ksmbd connectionNamjae Jeon1-1/+1
free_transport function for tcp connection can be called from smbdirect. It will cause kernel oops. This patch add free_transport ops in ksmbd connection, and add each free_transports for tcp and smbdirect. Fixes: 21a4e47578d4 ("ksmbd: fix use-after-free in __smb2_lease_break_noti()") Reviewed-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-04-14ksmbd: fix use-after-free in __smb2_lease_break_noti()Namjae Jeon1-1/+3
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>
2025-03-10ksmbd: prevent connection release during oplock break notificationNamjae Jeon1-0/+20
ksmbd_work could be freed when after connection release. Increment r_count of ksmbd_conn to indicate that requests are not finished yet and to not release the 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>
2024-12-15ksmbd: fix broken transfers when exceeding max simultaneous operationsMarios Makassikis1-2/+11
Since commit 0a77d947f599 ("ksmbd: check outstanding simultaneous SMB operations"), ksmbd enforces a maximum number of simultaneous operations for a connection. The problem is that reaching the limit causes ksmbd to close the socket, and the client has no indication that it should have slowed down. This behaviour can be reproduced by setting "smb2 max credits = 128" (or lower), and transferring a large file (25GB). smbclient fails as below: $ smbclient //192.168.1.254/testshare -U user%pass smb: \> put file.bin cli_push returned NT_STATUS_USER_SESSION_DELETED putting file file.bin as \file.bin smb2cli_req_compound_submit: Insufficient credits. 0 available, 1 needed NT_STATUS_INTERNAL_ERROR closing remote file \file.bin smb: \> smb2cli_req_compound_submit: Insufficient credits. 0 available, 1 needed Windows clients fail with 0x8007003b (with smaller files even). Fix this by delaying reading from the socket until there's room to allocate a request. This effectively applies backpressure on the client, so the transfer completes, albeit at a slower rate. Fixes: 0a77d947f599 ("ksmbd: check outstanding simultaneous SMB operations") Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-12-15ksmbd: count all requests in req_running counterMarios Makassikis1-2/+3
This changes the semantics of req_running to count all in-flight requests on a given connection, rather than the number of elements in the conn->request list. The latter is used only in smb2_cancel, and the counter is not used Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-11-25ksmbd: add debug print for pending request during server shutdownNamjae Jeon1-0/+1
We need to know how many pending requests are left at the end of server shutdown. That means we need to know how long the server will wait to process pending requests in case of a server shutdown. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-11-25ksmbd: use msleep instaed of schedule_timeout_interruptible()Namjae Jeon1-1/+1
use msleep instaed of schedule_timeout_interruptible() to guarantee the task delays as expected. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-11-25ksmbd: use __GFP_RETRY_MAYFAILNamjae Jeon1-2/+2
Prefer to report ENOMEM rather than incur the oom for allocations in ksmbd. __GFP_NORETRY could not achieve that, It would fail the allocations just too easily. __GFP_RETRY_MAYFAIL will keep retrying the allocation until there is no more progress and fail the allocation instead go OOM and let the caller to deal with it. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-11-05ksmbd: check outstanding simultaneous SMB operationsNamjae Jeon1-0/+1
If Client send simultaneous SMB operations to ksmbd, It exhausts too much memory through the "ksmbd_work_cache”. It will cause OOM issue. ksmbd has a credit mechanism but it can't handle this problem. This patch add the check if it exceeds max credits to prevent this problem by assuming that one smb request consumes at least one credit. Cc: stable@vger.kernel.org # v5.15+ 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>
2024-09-25ksmbd: Correct typos in multiple comments across various filesShen Lichuan1-1/+1
Fixed some confusing typos that were currently identified witch codespell, the details are as follows: -in the code comments: fs/smb/common/smb2pdu.h:9: specfication ==> specification fs/smb/common/smb2pdu.h:494: usally ==> usually fs/smb/common/smb2pdu.h:1064: Attrubutes ==> Attributes fs/smb/server/connection.c:28: cleand ==> cleaned fs/smb/server/ksmbd_netlink.h:216: struture ==> structure fs/smb/server/oplock.c:799: conains ==> contains fs/smb/server/oplock.c:1487: containted ==> contained fs/smb/server/server.c:282: proccessing ==> processing fs/smb/server/smb_common.c:491: comforms ==> conforms fs/smb/server/xattr.h:102: ATTRIBUITE ==> ATTRIBUTE Signed-off-by: Shen Lichuan <shenlichuan@vivo.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-09-14ksmbd: add refcnt to ksmbd_conn structNamjae Jeon1-1/+3
When sending an oplock break request, opinfo->conn is used, But freed ->conn can be used on multichannel. This patch add a reference count to the ksmbd_conn struct so that it can be freed when it is no longer used. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-08-18ksmbd: fix race condition between destroy_previous_session() and smb2 ↵Namjae Jeon1-1/+33
operations() If there is ->PreviousSessionId field in the session setup request, The session of the previous connection should be destroyed. During this, if the smb2 operation requests in the previous session are being processed, a racy issue could happen with ksmbd_destroy_file_table(). This patch sets conn->status to KSMBD_SESS_NEED_RECONNECT to block incoming operations and waits until on-going operations are complete (i.e. idle) before desctorying the previous session. Fixes: c8efcc786146 ("ksmbd: add support for durable handles v1/v2") Cc: stable@vger.kernel.org # v6.6+ Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-25040 Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-01-14ksmbd: fix UAF issue in ksmbd_tcp_new_connection()Namjae Jeon1-6/+0
The race is between the handling of a new TCP connection and its disconnection. It leads to UAF on `struct tcp_transport` in ksmbd_tcp_new_connection() function. Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-22991 Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-01-09ksmbd: Add missing set_freezable() for freezable kthreadKevin Hao1-0/+1
The kernel thread function ksmbd_conn_handler_loop() invokes the try_to_freeze() in its loop. But all the kernel threads are non-freezable by default. So if we want to make a kernel thread to be freezable, we have to invoke set_freezable() explicitly. Signed-off-by: Kevin Hao <haokexin@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-10-30ksmbd: no need to wait for binded connection termination at logoffNamjae Jeon1-16/+0
The connection could be binded to the existing session for Multichannel. session will be destroyed when binded connections are released. So no need to wait for that's connection at logoff. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-10-04ksmbd: fix race condition between session lookup and expireNamjae Jeon1-0/+2
Thread A + Thread B ksmbd_session_lookup | smb2_sess_setup sess = xa_load | | | xa_erase(&conn->sessions, sess->id); | | ksmbd_session_destroy(sess) --> kfree(sess) | // UAF! | sess->last_active = jiffies | + This patch add rwsem to fix race condition between ksmbd_session_lookup and ksmbd_expire_session. Reported-by: luosili <rootlab@huawei.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-09-21ksmbd: check iov vector index in ksmbd_conn_write()Namjae Jeon1-0/+3
If ->iov_idx is zero, This means that the iov vector for the response was not added during the request process. In other words, it means that there is a problem in generating a response, So this patch return as an error to avoid NULL pointer dereferencing problem. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>