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3 daystreewide: refresh kmalloc_obj() conversionsKees Cook
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>
6 daysksmbd: fix tree connection use-after-free in smb2_tree_connect()Cen Zhang (Microsoft Security FORGE Labs)
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: 33b235a6e6eb ("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>
6 daysksmbd: validate COPYCHUNK source and target rangesAlon Shakevsky
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: 8482150a0743 ("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>
6 daysksmbd: fix use-after-free in oplock break notificationAbdifatah Suruur
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: b003086d7696 ("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>
6 daysksmbd: fix sparc build with atomic work stateNamjae Jeon
Use an unsigned int for the work state so xchg() uses a supported 4-byte operation on sparc. Fixes: d12168084c8c ("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>
8 daysksmbd: validate normalized name response lengthAlon Shakevsky
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: 10aeff72ab82 ("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>
8 daysksmbd: fix listener task lifetime on netdev eventsNamjae Jeon
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: 3316a8fc840d ("ksmbd: server: avoid busy polling in accept loop") Reported-by: Farhad Alemi <farhad.alemi@berkeley.edu> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
8 daysksmbd: prevent out-of-bounds reads in share config responsesNamjae Jeon
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: a677ebd8ca2f ("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>
8 daysksmbd: rate limit unmapped SID errorsNamjae Jeon
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: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Reported-by: Cheryl Babcock <cheryl@renat.io> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
8 daysksmbd: propagate DACL parsing errorsNamjae Jeon
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: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Reported-by: Cheryl Babcock <cheryl@renat.io> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
8 daysksmbd: zero pipe read compound paddingNamjae Jeon
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: e2b76ab8b5c9 ("ksmbd: add support for read compound") Reported-by: Cheryl Babcock <cheryl@renat.io> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
8 daysksmbd: safely drain sessions during logoffNamjae Jeon
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>
8 daysksmbd: fill in FileSysIdentifier in FS_POSIX_INFORMATIONAleksandr Khromov
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: e2f34481b24d ("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>
8 daysksmbd: initialize FileSystemControlFlags in FS_CONTROL_INFORMATIONAleksandr Khromov
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: e2f34481b24d ("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>
8 daysksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it inAleksandr Khromov
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: e2f34481b24d ("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>
2026-08-23Merge tag 'ksmbd-for-7.3-rc1' of ↵Linus Torvalds
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 ...
2026-08-20smb: server: remove unused DES crypto headerNamjae Jeon
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: ce812992f239 ("ksmbd: remove NTLMv1 authentication") Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-20smb: server: Remove obsolete "select CRYPTO_LIB_DES" from Kconfig fileThomas Huth
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: ce812992f239f ("ksmbd: remove NTLMv1 authentication") Signed-off-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-20ksmbd: keep TCP timers alive for kernel socketsNamjae Jeon
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>
2026-08-20ksmbd: enable TCP keepalive for accepted connectionsNamjae Jeon
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>
2026-08-17Merge tag 'libcrypto-updates-for-linus' of ↵Linus Torvalds
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
2026-08-17Merge tag 'vfs-7.3-rc1.kthread' of ↵Linus Torvalds
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 ...
2026-08-17smb/server: fix session counter on session removalZe Tan
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: b38f99c1217a ("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>
2026-08-17smb/server: update session counter under sessions table lockZe Tan
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: b38f99c1217a ("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>
2026-08-17smb/server: fix session leak in ksmbd_session_register()Ze Tan
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: f5c779b7ddbd ("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>
2026-08-17smb/server: warn if ksmbd_proc_create() failsZe Tan
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: bound smb_check_perm_dacl() ACE walks by DACL sizeHang Nan
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: 8f0541186e9a ("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>
2026-08-17ksmbd: make RDMA encryption diagnostics conditionalNamjae Jeon
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>
2026-08-17ksmbd: add SMB Direct RDMA encryption transformNamjae Jeon
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: handle encrypted compressed requestsNamjae Jeon
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: a08de24c2b85 ("ksmbd: negotiate and decode SMB2 compression") Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17ksmbd: decrypt requests from expired encrypted sessionsNamjae Jeon
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: fa9415d4024f ("ksmbd: mark SMB2_SESSION_EXPIRED to session when destroying previous session") Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17ksmbd: disconnect on SMB3 decryption failureNamjae Jeon
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: encrypt interim responses to encrypted requestsNamjae Jeon
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>
2026-08-17ksmbd: scope session state changes to bound connectionsNamjae Jeon
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>
2026-08-17ksmbd: fix encrypted request lookup on bound channelsNamjae Jeon
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: f5a544e3bab7 ("ksmbd: add support for SMB3 multichannel") Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17ksmbd: add per-share SMB3 encryption enforcementNamjae Jeon
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>
2026-08-17ksmbd: notify parent directory leases on child createNamjae Jeon
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>
2026-08-17ksmbd: implement SMB2 AppInstanceVersion takeoverNamjae Jeon
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>
2026-08-17ksmbd: accept unspecified volatile ID on durable reconnectNamjae Jeon
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>
2026-08-17smb/server: fix tree connection leak in smb2_tree_connect()Ze Tan
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: e2b76ab8b5c9 ("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>
2026-08-17ksmbd: wait for deferred notify cancellationNamjae Jeon
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>
2026-08-17smb/server: fix use-after-free in ksmbd_conn_transport_destroy()ChenXiaoSong
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>
2026-08-17ksmbd: detach blocked lock requests before freeingNamjae Jeon
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: d63528eb0d43 ("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>
2026-08-17smb: server: Clear Preauth_HashValue in smb2pdu.c with kfree_sensitive()Thomas Huth
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>
2026-08-17smb: server: Free sensitive data in connection.c with kfree_sensitive()Thomas Huth
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>
2026-08-17smb: server: Free session data in user_session.c with kfree_sensitive()Thomas Huth
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>
2026-08-17smb: server: Make sure that passkey is not leaked on the heap in user_config.cThomas Huth
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>
2026-08-17smb: server: Clear sensitive stack and heap data in auth.cThomas Huth
Sensitive data like keys that are stored in stack-local arrays could be leaked via the stack to the calling functions, or via the heap when using only normal kfree() functions. There is no known vulnaribility for this right now, but it's good security style to explicitly zeroize this sensitive matieral as soon as possible to avoid that it could be exploited together with other bugs later. In calc_ntlmv2_hash(), the struct hmac_md5_ctx is normally cleared during hmac_md5_final() already, but in case of errors, this function is skipped and ctx is never zeroized, so add a memzero_explicit(&ctx, sizeof(ctx)) there to fix the problem. In ksmbd_krb5_authenticate(), the ksmbd_spnego_authen_response contains the session key in the payload. It's currently freed with plain kvfree(). Let's better use kvfree_sensitive() instead. In generate_key(), the prfhash[] array is used to calculate the key, but it's never cleared, so it leaks on the stack. Thus clear this with a memzero_explicit(), too. In ksmbd_crypt_message(), the sign[] and key[] arrays are leaked via the stack, too. Make sure to clear them via memzero_explicit() at the end. Signed-off-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17ksmbd: fix heap out-of-bounds write in krb5_authenticate()Ilan Dudnik
In krb5_authenticate(), out_len is calculated to determine available headroom in response_buf for the incoming Kerberos AP-REP token. However, when SMB2_SESSION_SETUP is processed as a non-first element of a compounded SMB2 request, the calculation omits work->next_smb2_rsp_hdr_off. This causes out_len to overstate remaining buffer headroom by the cumulative size of prior responses in the compound chain. Consequently, the length check in ksmbd_krb5_authenticate() (*out_len <= resp->spnego_blob_len) passes erroneously, allowing memcpy() to write the AP-REP blob past the end of response_buf into adjacent kernel heap memory. Fix this by subtracting work->next_smb2_rsp_hdr_off when computing out_len, ensuring it accurately reflects physical remaining buffer space. Signed-off-by: Ilan Dudnik <ilan.dudnik@safebreach.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-08-17smb/server: deny overwriting targets with non-POSIX opensChenXiaoSong
Reproducer: 1. server: systemctl start ksmbd 2. client: mount without `posix` option mount -t cifs //${server_ip}/export /mnt 3. client: touch /mnt/file1 /mnt/file2 4. client: C program: int fd = open("/mnt/file2", O_RDONLY); 5. client: C program: rename("/mnt/file1", "/mnt/file2"); 6. client: C program: struct stat stbuf; fstat(fd, &stbuf); stbuf.st_nlink is 1, should be 0 This patch fixes xfstests generic/035 when mounted without `posix` option. Suggested-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>