kernel/linux.git/fs/smb/server/mgmt/user_session.c, branch linux-7.0.y

ksmbd: scope conn->binding slowpath to bound sessions only

2026-05-23T11:09:22+00:00

[ Upstream commit b0da97c034b6107d14e537e212d4ce8b22109a58 ] When the binding SESSION_SETUP sets conn->binding = true, the flag stays set after the call so that the global session lookup in ksmbd_session_lookup_all() can find the session, which was not added to conn->sessions. Because the flag is connection-wide, the global lookup path will also resolve any other session by id if asked. Tighten the global lookup so that the returned session must have this connection registered in its channel xarray (sess->ksmbd_chann_list). The channel entry is installed by the existing binding_session path in ntlm_authenticate()/krb5_authenticate() when a SESSION_SETUP completes successfully, so this condition is a strict equivalent of "this connection has been accepted as a channel of this session". Connections that have not bound to a given session cannot reach it via the global table. The existing conn->binding gate for entering the slowpath is preserved so that non-binding connections keep the fast-path-only behavior, and the session->state check is unchanged. Fixes: f5a544e3bab7 ("ksmbd: add support for SMB3 multichannel") Signed-off-by: Hyunwoo Kim Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Sasha Levin

ksmbd: destroy tree_conn_ida in ksmbd_session_destroy()

2026-05-23T11:09:21+00:00

[ Upstream commit c049ee14eb4343b69b6f7755563f961f5e153423 ] When per-session tree_conn_ida was converted from a dynamically allocated ksmbd_ida to an embedded struct ida, ksmbd_ida_free() was removed from ksmbd_session_destroy() but no matching ida_destroy() was added. The session 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 enclosing session is freed. Also move ida_init() to right after the session is allocated so that it is always paired with the destroy call even on the early error paths of __session_create() (ksmbd_init_file_table() or __init_smb2_session() failures), both of which jump to the error label and invoke ksmbd_session_destroy() on a partially initialised session. 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 Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Sasha Levin

ksmbd: validate owner of durable handle on reconnect

2026-04-27T13:30:16+00:00

[ Upstream commit 49110a8ce654bbe56bef7c5e44cce31f4b102b8a ] Currently, ksmbd does not verify if the user attempting to reconnect to a durable handle is the same user who originally opened the file. This allows any authenticated user to hijack an orphaned durable handle by predicting or brute-forcing the persistent ID. According to MS-SMB2, the server MUST verify that the SecurityContext of the reconnect request matches the SecurityContext associated with the existing open. Add a durable_owner structure to ksmbd_file to store the original opener's UID, GID, and account name. and catpure the owner information when a file handle becomes orphaned. and implementing ksmbd_vfs_compare_durable_owner() to validate the identity of the requester during SMB2_CREATE (DHnC). Fixes: c8efcc786146 ("ksmbd: add support for durable handles v1/v2") Reported-by: Davide Ornaghi Reported-by: Navaneeth K Signed-off-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

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

ksmbd: fix non-IPv6 build

2026-02-10T18:58:10+00:00

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 Acked-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: convert tree_conns_lock to rw_semaphore

2026-02-09T23:48:53+00:00

Converts tree_conns_lock to an rw_semaphore to allow sleeping while the lock is held. Additionally, it simplifies the locking logic in ksmbd_tree_conn_session_logoff() and introduces __ksmbd_tree_conn_disconnect() to avoid redundant locking. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: fix missing chann_lock while iterating session channel list

2026-02-09T23:48:51+00:00

Add chann_lock while iterating ksmbd_chann_list in show_proc_session() and show_proc_sessions(). This will prevents a race condition with concurrent channel list modifications. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: add chann_lock to protect ksmbd_chann_list xarray

2026-02-09T15:03:04+00:00

ksmbd_chann_list xarray lacks synchronization, allowing use-after-free in multi-channel sessions (between lookup_chann_list() and ksmbd_chann_del). Adds rw_semaphore chann_lock to struct ksmbd_session and protects all xa_load/xa_store/xa_erase accesses. Cc: stable@vger.kernel.org Reported-by: Igor Stepansky Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: add procfs interface for runtime monitoring and statistics

2026-02-09T02:25:16+00:00

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/) 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 Signed-off-by: Bahubali B Gumaji Signed-off-by: Sang-Soo Lee Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: Fix refcount leak when invalid session is found on session lookup

2025-12-15T00:35:56+00:00

When a session is found but its state is not SMB2_SESSION_VALID, It indicates that no valid session was found, but it is missing to decrement the reference count acquired by the session lookup, which results in a reference count leak. This patch fixes the issue by explicitly calling ksmbd_user_session_put to release the reference to the session. Cc: stable@vger.kernel.org Reported-by: Alexandre Reported-by: Stanislas Polu Signed-off-by: Namjae Jeon Signed-off-by: Steve French