Commit Graph

298 Commits

Author SHA1 Message Date
Guenter Roeck
d1e8b015bc smb/server: Fix another refcount leak in smb2_open()
[ Upstream commit c15e7c62fe ]

If ksmbd_override_fsids() fails, we jump to err_out2. At that point, fp is
NULL because it hasn't been assigned dh_info.fp yet, so ksmbd_fd_put(work,
fp) will not be called. However, dh_info.fp was already inserted into the
session file table by ksmbd_reopen_durable_fd(), so it will leak in the
session file table until the session is closed.

Move fp = dh_info.fp; ahead of the ksmbd_override_fsids() check to fix the
problem.

Found by an experimental AI code review agent at Google.

Fixes: c8efcc7861 ("ksmbd: add support for durable handles v1/v2")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-25 11:08:26 +01:00
Namjae Jeon
4c2ca31608 ksmbd: add chann_lock to protect ksmbd_chann_list xarray
[ Upstream commit 4f3a06cc57 ]

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 <igor.stepansky@orca.security>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-13 17:20:30 +01:00
Namjae Jeon
c9c00b85b8 ksmbd: check return value of xa_store() in krb5_authenticate
[ Upstream commit ecd9d6bf88 ]

xa_store() may fail so check its return value and return error code if
error occurred.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Stable-dep-of: 4f3a06cc57 ("ksmbd: add chann_lock to protect ksmbd_chann_list xarray")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-13 17:20:30 +01:00
Henrique Carvalho
baf664fc90 smb: server: fix leak of active_num_conn in ksmbd_tcp_new_connection()
commit 77ffbcac4e upstream.

On kthread_run() failure in ksmbd_tcp_new_connection(), the transport is
freed via free_transport(), which does not decrement active_num_conn,
leaking this counter.

Replace free_transport() with ksmbd_tcp_disconnect().

Fixes: 0d0d4680db ("ksmbd: add max connections parameter")
Cc: stable@vger.kernel.org
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-16 10:18:43 +01:00
Namjae Jeon
f7b1c2f564 ksmbd: fix infinite loop caused by next_smb2_rcv_hdr_off reset in error paths
commit 010eb01ce2 upstream.

The problem occurs when a signed request fails smb2 signature verification
check. In __process_request(), if check_sign_req() returns an error,
set_smb2_rsp_status(work, STATUS_ACCESS_DENIED) is called.
set_smb2_rsp_status() set work->next_smb2_rcv_hdr_off as zero. By resetting
next_smb2_rcv_hdr_off to zero, the pointer to the next command in the chain
is lost. Consequently, is_chained_smb2_message() continues to point to
the same request header instead of advancing. If the header's NextCommand
field is non-zero, the function returns true, causing __handle_ksmbd_work()
to repeatedly process the same failed request in an infinite loop.
This results in the kernel log being flooded with "bad smb2 signature"
messages and high CPU usage.

This patch fixes the issue by changing the return value from
SERVER_HANDLER_CONTINUE to SERVER_HANDLER_ABORT. This ensures that
the processing loop terminates immediately rather than attempting to
continue from an invalidated offset.

Reported-by: tianshuo han <hantianshuo233@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-16 10:18:43 +01:00
ZhangGuoDong
8a15107c4c smb/server: fix refcount leak in parse_durable_handle_context()
[ Upstream commit 3296c3012a ]

When the command is a replay operation and -ENOEXEC is returned,
the refcount of ksmbd_file must be released.

Signed-off-by: ZhangGuoDong <zhangguodong@kylinos.cn>
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-02-11 13:40:19 +01:00
ZhangGuoDong
39ca11ff15 smb/server: fix refcount leak in smb2_open()
[ Upstream commit f416c55699 ]

When ksmbd_vfs_getattr() fails, the reference count of ksmbd_file
must be released.

Suggested-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: ZhangGuoDong <zhangguodong@kylinos.cn>
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-02-11 13:40:19 +01:00
ZhangGuoDong
ac18761b53 smb/server: call ksmbd_session_rpc_close() on error path in create_smb2_pipe()
[ Upstream commit 7c28f8eef5 ]

When ksmbd_iov_pin_rsp() fails, we should call ksmbd_session_rpc_close().

Signed-off-by: ZhangGuoDong <zhangguodong@kylinos.cn>
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-02-11 13:40:19 +01:00
Thomas Fourier
70ba85e439 ksmbd: smbd: fix dma_unmap_sg() nents
[ Upstream commit 98e3e2b561 ]

The dma_unmap_sg() functions should be called with the same nents as the
dma_map_sg(), not the value the map function returned.

Fixes: 0626e6641f ("cifsd: add server handler for central processing and tranport layers")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
[ Context ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-06 16:55:49 +01:00
Zilin Guan
6769070042 ksmbd: Fix memory leak in get_file_all_info()
[ Upstream commit 0c56693b06 ]

In get_file_all_info(), if vfs_getattr() fails, the function returns
immediately without freeing the allocated filename, leading to a memory
leak.

Fix this by freeing the filename before returning in this error case.

Fixes: 5614c8c487 ("ksmbd: replace generic_fillattr with vfs_getattr")
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-08 10:14:37 +01:00
Namjae Jeon
d26af6d14d ksmbd: fix buffer validation by including null terminator size in EA length
commit 95d7a890e4 upstream.

The smb2_set_ea function, which handles Extended Attributes (EA),
was performing buffer validation checks that incorrectly omitted the size
of the null terminating character (+1 byte) for EA Name.
This patch fixes the issue by explicitly adding '+ 1' to EaNameLength where
the null terminator is expected to be present in the buffer, ensuring
the validation accurately reflects the total required buffer size.

Cc: stable@vger.kernel.org
Reported-by: Roger <roger.andersen@protonmail.com>
Reported-by: Stanislas Polu <spolu@dust.tt>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-08 10:14:06 +01:00
Namjae Jeon
02e06785e8 ksmbd: Fix refcount leak when invalid session is found on session lookup
commit cafb57f7bd upstream.

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 <roger.andersen@protonmail.com>
Reported-by: Stanislas Polu <spolu@dust.tt>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-08 10:14:06 +01:00
Qianchang Zhao
a6f4cfa378 ksmbd: skip lock-range check on equal size to avoid size==0 underflow
commit 5d510ac316 upstream.

When size equals the current i_size (including 0), the code used to call
check_lock_range(filp, i_size, size - 1, WRITE), which computes `size - 1`
and can underflow for size==0. Skip the equal case.

Cc: stable@vger.kernel.org
Reported-by: Qianchang Zhao <pioooooooooip@gmail.com>
Reported-by: Zhitong Liu <liuzhitong1993@gmail.com>
Signed-off-by: Qianchang Zhao <pioooooooooip@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-08 10:14:06 +01:00
Qianchang Zhao
ccc7878104 ksmbd: vfs: fix race on m_flags in vfs_cache
[ Upstream commit 991f8a79db ]

ksmbd maintains delete-on-close and pending-delete state in
ksmbd_inode->m_flags. In vfs_cache.c this field is accessed under
inconsistent locking: some paths read and modify m_flags under
ci->m_lock while others do so without taking the lock at all.

Examples:

 - ksmbd_query_inode_status() and __ksmbd_inode_close() use
   ci->m_lock when checking or updating m_flags.
 - ksmbd_inode_pending_delete(), ksmbd_set_inode_pending_delete(),
   ksmbd_clear_inode_pending_delete() and ksmbd_fd_set_delete_on_close()
   used to read and modify m_flags without ci->m_lock.

This creates a potential data race on m_flags when multiple threads
open, close and delete the same file concurrently. In the worst case
delete-on-close and pending-delete bits can be lost or observed in an
inconsistent state, leading to confusing delete semantics (files that
stay on disk after delete-on-close, or files that disappear while still
in use).

Fix it by:

 - Making ksmbd_query_inode_status() look at m_flags under ci->m_lock
   after dropping inode_hash_lock.
 - Adding ci->m_lock protection to all helpers that read or modify
   m_flags (ksmbd_inode_pending_delete(), ksmbd_set_inode_pending_delete(),
   ksmbd_clear_inode_pending_delete(), ksmbd_fd_set_delete_on_close()).
 - Keeping the existing ci->m_lock protection in __ksmbd_inode_close(),
   and moving the actual unlink/xattr removal outside the lock.

This unifies the locking around m_flags and removes the data race while
preserving the existing delete-on-close behaviour.

Reported-by: Qianchang Zhao <pioooooooooip@gmail.com>
Reported-by: Zhitong Liu <liuzhitong1993@gmail.com>
Signed-off-by: Qianchang Zhao <pioooooooooip@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-08 10:13:58 +01:00
Namjae Jeon
21a3d01fc6 ksmbd: fix use-after-free in ksmbd_tree_connect_put under concurrency
[ Upstream commit b39a1833cc ]

Under high concurrency, A tree-connection object (tcon) is freed on
a disconnect path while another path still holds a reference and later
executes *_put()/write on it.

Reported-by: Qianchang Zhao <pioooooooooip@gmail.com>
Reported-by: Zhitong Liu <liuzhitong1993@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-08 10:13:58 +01:00
ChenXiaoSong
2770b46167 smb/server: fix return value of smb2_ioctl()
[ Upstream commit 269df046c1 ]

__process_request() will not print error messages if smb2_ioctl()
always returns 0.

Fix this by returning the correct value at the end of function.

Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-08 10:13:58 +01:00
Qianchang Zhao
5ac763713a ksmbd: ipc: fix use-after-free in ipc_msg_send_request
commit 1fab1fa091 upstream.

ipc_msg_send_request() waits for a generic netlink reply using an
ipc_msg_table_entry on the stack. The generic netlink handler
(handle_generic_event()/handle_response()) fills entry->response under
ipc_msg_table_lock, but ipc_msg_send_request() used to validate and free
entry->response without holding the same lock.

Under high concurrency this allows a race where handle_response() is
copying data into entry->response while ipc_msg_send_request() has just
freed it, leading to a slab-use-after-free reported by KASAN in
handle_generic_event():

  BUG: KASAN: slab-use-after-free in handle_generic_event+0x3c4/0x5f0 [ksmbd]
  Write of size 12 at addr ffff888198ee6e20 by task pool/109349
  ...
  Freed by task:
    kvfree
    ipc_msg_send_request [ksmbd]
    ksmbd_rpc_open -> ksmbd_session_rpc_open [ksmbd]

Fix by:
- Taking ipc_msg_table_lock in ipc_msg_send_request() while validating
  entry->response, freeing it when invalid, and removing the entry from
  ipc_msg_table.
- Returning the final entry->response pointer to the caller only after
  the hash entry is removed under the lock.
- Returning NULL in the error path, preserving the original API
  semantics.

This makes all accesses to entry->response consistent with
handle_response(), which already updates and fills the response buffer
under ipc_msg_table_lock, and closes the race that allowed the UAF.

Cc: stable@vger.kernel.org
Reported-by: Qianchang Zhao <pioooooooooip@gmail.com>
Reported-by: Zhitong Liu <liuzhitong1993@gmail.com>
Signed-off-by: Qianchang Zhao <pioooooooooip@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-12 18:37:18 +01:00
Joshua Rogers
4587a7826b ksmbd: close accepted socket when per-IP limit rejects connection
commit 98a5fd31cb upstream.

When the per-IP connection limit is exceeded in ksmbd_kthread_fn(),
the code sets ret = -EAGAIN and continues the accept loop without
closing the just-accepted socket. That leaks one socket per rejected
attempt from a single IP and enables a trivial remote DoS.

Release client_sk before continuing.

This bug was found with ZeroPath.

Cc: stable@vger.kernel.org
Signed-off-by: Joshua Rogers <linux@joshua.hu>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-24 10:35:59 +01:00
ZhangGuoDong
dcc51dfe6f smb/server: fix possible refcount leak in smb2_sess_setup()
[ Upstream commit 379510a815 ]

Reference count of ksmbd_session will leak when session need reconnect.
Fix this by adding the missing ksmbd_user_session_put().

Co-developed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: ZhangGuoDong <zhangguodong@kylinos.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24 10:35:48 +01:00
ZhangGuoDong
f130558773 smb/server: fix possible memory leak in smb2_read()
[ Upstream commit 6fced056d2 ]

Memory leak occurs when ksmbd_vfs_read() fails.
Fix this by adding the missing kvfree().

Co-developed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: ZhangGuoDong <zhangguodong@kylinos.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24 10:35:48 +01:00
Namjae Jeon
c55305efbc ksmbd: use sock_create_kern interface to create kernel socket
[ Upstream commit 3677ca67b9 ]

we should use sock_create_kern() if the socket resides in kernel space.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-13 15:34:32 -05:00
Qianchang Zhao
898d527ed9 ksmbd: transport_ipc: validate payload size before reading handle
commit 6f40e50ceb upstream.

handle_response() dereferences the payload as a 4-byte handle without
verifying that the declared payload size is at least 4 bytes. A malformed
or truncated message from ksmbd.mountd can lead to a 4-byte read past the
declared payload size. Validate the size before dereferencing.

This is a minimal fix to guard the initial handle read.

Fixes: 0626e6641f ("cifsd: add server handler for central processing and tranport layers")
Cc: stable@vger.kernel.org
Reported-by: Qianchang Zhao <pioooooooooip@gmail.com>
Signed-off-by: Qianchang Zhao <pioooooooooip@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-29 14:09:02 +01:00
Stefan Metzmacher
a135fc271d smb: server: let smb_direct_flush_send_list() invalidate a remote key first
[ Upstream commit 1b53426334 ]

If we want to invalidate a remote key we should do that as soon as
possible, so do it in the first send work request.

Acked-by: 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>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-29 14:08:53 +01:00
Marios Makassikis
4602b8cee1 ksmbd: fix recursive locking in RPC handle list access
[ Upstream commit 88f170814f ]

Since commit 305853cce3 ("ksmbd: Fix race condition in RPC handle list
access"), ksmbd_session_rpc_method() attempts to lock sess->rpc_lock.

This causes hung connections / tasks when a client attempts to open
a named pipe. Using Samba's rpcclient tool:

 $ rpcclient //192.168.1.254 -U user%password
 $ rpcclient $> srvinfo
 <connection hung here>

Kernel side:
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:kworker/0:0 state:D stack:0 pid:5021 tgid:5021 ppid:2 flags:0x00200000
  Workqueue: ksmbd-io handle_ksmbd_work
  Call trace:
  __schedule from schedule+0x3c/0x58
  schedule from schedule_preempt_disabled+0xc/0x10
  schedule_preempt_disabled from rwsem_down_read_slowpath+0x1b0/0x1d8
  rwsem_down_read_slowpath from down_read+0x28/0x30
  down_read from ksmbd_session_rpc_method+0x18/0x3c
  ksmbd_session_rpc_method from ksmbd_rpc_open+0x34/0x68
  ksmbd_rpc_open from ksmbd_session_rpc_open+0x194/0x228
  ksmbd_session_rpc_open from create_smb2_pipe+0x8c/0x2c8
  create_smb2_pipe from smb2_open+0x10c/0x27ac
  smb2_open from handle_ksmbd_work+0x238/0x3dc
  handle_ksmbd_work from process_scheduled_works+0x160/0x25c
  process_scheduled_works from worker_thread+0x16c/0x1e8
  worker_thread from kthread+0xa8/0xb8
  kthread from ret_from_fork+0x14/0x38
  Exception stack(0x8529ffb0 to 0x8529fff8)

The task deadlocks because the lock is already held:
  ksmbd_session_rpc_open
    down_write(&sess->rpc_lock)
    ksmbd_rpc_open
      ksmbd_session_rpc_method
        down_read(&sess->rpc_lock)   <-- deadlock

Adjust ksmbd_session_rpc_method() callers to take the lock when necessary.

Fixes: 305853cce3 ("ksmbd: Fix race condition in RPC handle list access")
Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-23 16:20:30 +02:00
Namjae Jeon
8173dcfafe ksmbd: add max ip connections parameter
commit d8b6dc9256 upstream.

This parameter set the maximum number of connections per ip address.
The default is 8.

Cc: stable@vger.kernel.org
Fixes: c0d41112f1 ("ksmbd: extend the connection limiting mechanism to support IPv6")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-15 12:00:22 +02:00
Matvey Kovalev
b613671dc1 ksmbd: fix error code overwriting in smb2_get_info_filesystem()
commit 88daf2f448 upstream.

If client doesn't negotiate with SMB3.1.1 POSIX Extensions,
then proper error code won't be returned due to overwriting.

Return error immediately.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org
Signed-off-by: Matvey Kovalev <matvey.kovalev@ispras.ru>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-15 12:00:22 +02:00
Yunseong Kim
5cc679ba0f ksmbd: Fix race condition in RPC handle list access
commit 305853cce3 upstream.

The 'sess->rpc_handle_list' XArray manages RPC handles within a ksmbd
session. Access to this list is intended to be protected by
'sess->rpc_lock' (an rw_semaphore). However, the locking implementation was
flawed, leading to potential race conditions.

In ksmbd_session_rpc_open(), the code incorrectly acquired only a read lock
before calling xa_store() and xa_erase(). Since these operations modify
the XArray structure, a write lock is required to ensure exclusive access
and prevent data corruption from concurrent modifications.

Furthermore, ksmbd_session_rpc_method() accessed the list using xa_load()
without holding any lock at all. This could lead to reading inconsistent
data or a potential use-after-free if an entry is concurrently removed and
the pointer is dereferenced.

Fix these issues by:
1. Using down_write() and up_write() in ksmbd_session_rpc_open()
   to ensure exclusive access during XArray modification, and ensuring
   the lock is correctly released on error paths.
2. Adding down_read() and up_read() in ksmbd_session_rpc_method()
   to safely protect the lookup.

Fixes: a1f46c99d9 ("ksmbd: fix use-after-free in ksmbd_session_rpc_open")
Fixes: b685757c7b ("ksmbd: Implements sess->rpc_handle_list as xarray")
Cc: stable@vger.kernel.org
Signed-off-by: Yunseong Kim <ysk@kzalloc.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-15 12:00:22 +02:00
Stefan Metzmacher
180bb95b69 smb: server: fix IRD/ORD negotiation with the client
[ Upstream commit fad988a215 ]

Already do real negotiation in smb_direct_handle_connect_request()
where we see the requested initiator_depth and responder_resources
from the client.

We should detect legacy iwarp clients using MPA v1
with the custom IRD/ORD negotiation.

We need to send the custom IRD/ORD in big endian,
but we need to try to let clients with broken requests
using little endian (older cifs.ko) to work.

Note the reason why this uses u8 for
initiator_depth and responder_resources is
that the rdma layer also uses it.

Acked-by: 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
Cc: linux-rdma@vger.kernel.org
Fixes: 0626e6641f ("cifsd: add server handler for central processing and tranport layers")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 11:59:55 +02:00
Stefan Metzmacher
ecb6383b79 smb: server: use disable_work_sync in transport_rdma.c
[ Upstream commit f7f8925017 ]

This makes it safer during the disconnect and avoids
requeueing.

It's ok to call disable_work[_sync]() more than 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
Fixes: 0626e6641f ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-02 13:44:08 +02:00
Stefan Metzmacher
1d6e5bd5b6 smb: server: don't use delayed_work for post_recv_credits_work
[ Upstream commit 1cde0a74a7 ]

If we are using a hardcoded delay of 0 there's no point in
using delayed_work it only adds confusion.

The client also uses a normal work_struct and now
it is easier to move it to the common smbdirect_socket.

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: 0626e6641f ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-02 13:44:08 +02:00
Stefan Metzmacher
9644798294 ksmbd: smbdirect: verify remaining_data_length respects max_fragmented_recv_size
commit e1868ba37f upstream.

This is inspired by the check for data_offset + data_length.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: stable@vger.kernel.org
Fixes: 2ea086e35c ("ksmbd: add buffer validation for smb direct")
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-25 11:13:45 +02:00
Namjae Jeon
8be498fcbd ksmbd: smbdirect: validate data_offset and data_length field of smb_direct_data_transfer
commit 5282491fc4 upstream.

If data_offset and data_length of smb_direct_data_transfer struct are
invalid, out of bounds issue could happen.
This patch validate data_offset and data_length field in recv_done.

Cc: stable@vger.kernel.org
Fixes: 2ea086e35c ("ksmbd: add buffer validation for smb direct")
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reported-by: Luigino Camastra, Aisle Research <luigino.camastra@aisle.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-25 11:13:44 +02:00
Stefan Metzmacher
003e6a3150 smb: server: split ksmbd_rdma_stop_listening() out of ksmbd_rdma_destroy()
[ Upstream commit bac7b996d4 ]

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: 0626e6641f ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28 16:31:08 +02:00
Namjae Jeon
d5ab785183 ksmbd: extend the connection limiting mechanism to support IPv6
commit c0d41112f1 upstream.

Update the connection tracking logic to handle both IPv4 and IPv6
address families.

Cc: stable@vger.kernel.org
Fixes: e6bb919397 ("ksmbd: limit repeated connections from clients with the same IP")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:30:55 +02:00
Ziyan Xu
36e010bb86 ksmbd: fix refcount leak causing resource not released
commit 89bb430f62 upstream.

When ksmbd_conn_releasing(opinfo->conn) returns true,the refcount was not
decremented properly, causing a refcount leak that prevents the count from
reaching zero and the memory from being released.

Cc: stable@vger.kernel.org
Signed-off-by: Ziyan Xu <ziyan@securitygossip.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:30:55 +02:00
NeilBrown
814cfdb635 smb/server: avoid deadlock when linking with ReplaceIfExists
[ Upstream commit d5fc1400a3 ]

If smb2_create_link() is called with ReplaceIfExists set and the name
does exist then a deadlock will happen.

ksmbd_vfs_kern_path_locked() will return with success and the parent
directory will be locked.  ksmbd_vfs_remove_file() will then remove the
file.  ksmbd_vfs_link() will then be called while the parent is still
locked.  It will try to lock the same parent and will deadlock.

This patch moves the ksmbd_vfs_kern_path_unlock() call to *before*
ksmbd_vfs_link() and then simplifies the code, removing the file_present
flag variable.

Signed-off-by: NeilBrown <neil@brown.name>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-20 18:30:19 +02:00
Thorsten Blum
f54eef9be3 smb: server: Fix extension string in ksmbd_extract_shortname()
commit 8e7d178d06 upstream.

In ksmbd_extract_shortname(), strscpy() is incorrectly called with the
length of the source string (excluding the NUL terminator) rather than
the size of the destination buffer. This results in "__" being copied
to 'extension' rather than "___" (two underscores instead of three).

Use the destination buffer size instead to ensure that the string "___"
(three underscores) is copied correctly.

Cc: stable@vger.kernel.org
Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-15 12:14:11 +02:00
Namjae Jeon
7e5d91d3e6 ksmbd: limit repeated connections from clients with the same IP
commit e6bb919397 upstream.

Repeated connections from clients with the same IP address may exhaust
the max connections and prevent other normal client connections.
This patch limit repeated connections from clients with the same IP.

Reported-by: tianshuo han <hantianshuo233@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-15 12:14:11 +02:00
Namjae Jeon
68300f2738 ksmbd: fix corrupted mtime and ctime in smb2_open
commit 4f8ff9486f upstream.

If STATX_BASIC_STATS flags are not given as an argument to vfs_getattr,
It can not get ctime and mtime in kstat.

This causes a problem showing mtime and ctime outdated from cifs.ko.
File: /xfstest.test/foo
Size: 4096            Blocks: 8          IO Block: 1048576 regular file
Device: 0,65    Inode: 2033391     Links: 1
Access: (0755/-rwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)
Context: system_u:object_r:cifs_t:s0
Access: 2025-07-23 22:15:30.136051900 +0100
Modify: 1970-01-01 01:00:00.000000000 +0100
Change: 1970-01-01 01:00:00.000000000 +0100
Birth: 2025-07-23 22:15:30.136051900 +0100

Cc: stable@vger.kernel.org
Reported-by: David Howells <dhowells@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-15 12:14:11 +02:00
Namjae Jeon
edeecc7871 ksmbd: fix Preauh_HashValue race condition
commit 44a3059c4c upstream.

If client send multiple session setup requests to ksmbd,
Preauh_HashValue race condition could happen.
There is no need to free sess->Preauh_HashValue at session setup phase.
It can be freed together with session at connection termination phase.

Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-27661
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-15 12:14:11 +02:00
Namjae Jeon
2a30ed6428 ksmbd: fix null pointer dereference error in generate_encryptionkey
commit 9b493ab6f3 upstream.

If client send two session setups with krb5 authenticate to ksmbd,
null pointer dereference error in generate_encryptionkey could happen.
sess->Preauth_HashValue is set to NULL if session is valid.
So this patch skip generate encryption key if session is valid.

Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-27654
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-15 12:14:11 +02:00
Stefan Metzmacher
0d6d86b0a5 smb: server: let recv_done() avoid touching data_transfer after cleanup/move
[ Upstream commit a6c015b7ac ]

Calling enqueue_reassembly() and wake_up_interruptible(&t->wait_reassembly_queue)
or put_receive_buffer() means the recvmsg/data_transfer pointer might
get re-used by another thread, which means these should be
the last operations before calling return.

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: 0626e6641f ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15 12:14:08 +02:00
Stefan Metzmacher
3d970a2f24 smb: server: let recv_done() consistently call put_recvmsg/smb_direct_disconnect_rdma_connection
[ Upstream commit cfe76fdbb9 ]

We should call put_recvmsg() before smb_direct_disconnect_rdma_connection()
in order to call it before waking up the callers.

In all error cases we should call smb_direct_disconnect_rdma_connection()
in order to avoid stale connections.

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: 0626e6641f ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15 12:14:08 +02:00
Stefan Metzmacher
896af4c261 smb: server: make sure we call ib_dma_unmap_single() only if we called ib_dma_map_single already
[ Upstream commit afb4108c92 ]

In case of failures either ib_dma_map_single() might not be called yet
or ib_dma_unmap_single() was already called.

We should make sure put_recvmsg() only calls ib_dma_unmap_single() if needed.

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: 0626e6641f ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15 12:14:07 +02:00
Stefan Metzmacher
17d675f639 smb: server: remove separate empty_recvmsg_queue
[ Upstream commit 01027a62b5 ]

There's no need to maintain two lists, we can just
have a single list of receive buffers, which are free to use.

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: 0626e6641f ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15 12:14:07 +02:00
Namjae Jeon
815f1161d6 ksmbd: fix potential use-after-free in oplock/lease break ack
commit 50f930db22 upstream.

If ksmbd_iov_pin_rsp return error, use-after-free can happen by
accessing opinfo->state and opinfo_put and ksmbd_fd_put could
called twice.

Reported-by: Ziyan Xu <research@securitygossip.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-17 18:37:24 +02:00
Al Viro
3b16c9b8ba ksmbd: fix a mount write count leak in ksmbd_vfs_kern_path_locked()
commit 277627b431 upstream.

If the call of ksmbd_vfs_lock_parent() fails, we drop the parent_path
references and return an error.  We need to drop the write access we
just got on parent_path->mnt before we drop the mount reference - callers
assume that ksmbd_vfs_kern_path_locked() returns with mount write
access grabbed if and only if it has returned 0.

Fixes: 864fb5d371 ("ksmbd: fix possible deadlock in smb2_open")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-17 18:37:15 +02:00
Stefan Metzmacher
92c2c005a8 smb: server: make use of rdma_destroy_qp()
commit 0c2b53997e upstream.

The qp is created by rdma_create_qp() as t->cm_id->qp
and t->qp is just a shortcut.

rdma_destroy_qp() also calls ib_destroy_qp(cm_id->qp) internally,
but it is protected by a mutex, clears the cm_id and also calls
trace_cm_qp_destroy().

This should make the tracing more useful as both
rdma_create_qp() and rdma_destroy_qp() are traces and it makes
the code look more sane as functions from the same layer are used
for the specific qp object.

trace-cmd stream -e rdma_cma:cm_qp_create -e rdma_cma:cm_qp_destroy
shows this now while doing a mount and unmount from a client:

  <...>-80   [002] 378.514182: cm_qp_create:  cm.id=1 src=172.31.9.167:5445 dst=172.31.9.166:37113 tos=0 pd.id=0 qp_type=RC send_wr=867 recv_wr=255 qp_num=1 rc=0
  <...>-6283 [001] 381.686172: cm_qp_destroy: cm.id=1 src=172.31.9.167:5445 dst=172.31.9.166:37113 tos=0 qp_num=1

Before we only saw the first line.

Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <stfrench@microsoft.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Hyunchul Lee <hyc.lee@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Fixes: 0626e6641f ("cifsd: add server handler for central processing and tranport layers")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Tom Talpey <tom@talpey.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-17 18:37:15 +02:00
Namjae Jeon
229aa5b810 ksmbd: provide zero as a unique ID to the Mac client
[ Upstream commit 571781eb7f ]

The Mac SMB client code seems to expect the on-disk file identifier
to have the semantics of HFS+ Catalog Node Identifier (CNID).
ksmbd provides the inode number as a unique ID to the client,
but in the case of subvolumes of btrfs, there are cases where different
files have the same inode number, so the mac smb client treats it
as an error. There is a report that a similar problem occurs
when the share is ZFS.
Returning UniqueId of zero will make the Mac client to stop using and
trusting the file id returned from the server.

Reported-by: Justin Turner Arthur <justinarthur@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-06 11:01:33 +02:00
Namjae Jeon
0fce0027a5 ksmbd: allow a filename to contain special characters on SMB3.1.1 posix extension
[ Upstream commit dc3e0f17f7 ]

If client send SMB2_CREATE_POSIX_CONTEXT to ksmbd, Allow a filename
to contain special characters.

Reported-by: Philipp Kerling <pkerling@casix.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-06 11:01:33 +02:00