linux-toradex.git/fs/smb/server/server.c, branch v6.14-rc6 Linux kernel for Apalis and Colibri modules ksmbd: fix broken transfers when exceeding max simultaneous operations 2024-12-16T04:20:03+00:00 Marios Makassikis mmakassikis@freebox.fr 2024-12-14T03:17:23+00:00 43fb7bce8866e793275c4f9f25af6a37745f3416 Since commit 0a77d947f599 ("ksmbd: check outstanding simultaneous SMB operations"), ksmbd enforces a maximum number of simultaneous operations for a connection. The problem is that reaching the limit causes ksmbd to close the socket, and the client has no indication that it should have slowed down. This behaviour can be reproduced by setting "smb2 max credits = 128" (or lower), and transferring a large file (25GB). smbclient fails as below: $ smbclient //192.168.1.254/testshare -U user%pass smb: \> put file.bin cli_push returned NT_STATUS_USER_SESSION_DELETED putting file file.bin as \file.bin smb2cli_req_compound_submit: Insufficient credits. 0 available, 1 needed NT_STATUS_INTERNAL_ERROR closing remote file \file.bin smb: \> smb2cli_req_compound_submit: Insufficient credits. 0 available, 1 needed Windows clients fail with 0x8007003b (with smaller files even). Fix this by delaying reading from the socket until there's room to allocate a request. This effectively applies backpressure on the client, so the transfer completes, albeit at a slower rate. Fixes: 0a77d947f599 ("ksmbd: check outstanding simultaneous SMB operations") Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> 
Since commit 0a77d947f599 ("ksmbd: check outstanding simultaneous SMB
operations"), ksmbd enforces a maximum number of simultaneous operations
for a connection. The problem is that reaching the limit causes ksmbd to
close the socket, and the client has no indication that it should have
slowed down.

This behaviour can be reproduced by setting "smb2 max credits = 128" (or
lower), and transferring a large file (25GB).

smbclient fails as below:

  $ smbclient //192.168.1.254/testshare -U user%pass
  smb: \> put file.bin
  cli_push returned NT_STATUS_USER_SESSION_DELETED
  putting file file.bin as \file.bin smb2cli_req_compound_submit:
  Insufficient credits. 0 available, 1 needed
  NT_STATUS_INTERNAL_ERROR closing remote file \file.bin
  smb: \> smb2cli_req_compound_submit: Insufficient credits. 0 available,
  1 needed

Windows clients fail with 0x8007003b (with smaller files even).

Fix this by delaying reading from the socket until there's room to
allocate a request. This effectively applies backpressure on the client,
so the transfer completes, albeit at a slower rate.

Fixes: 0a77d947f599 ("ksmbd: check outstanding simultaneous SMB operations")
Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
ksmbd: fix racy issue from session lookup and expire 2024-12-10T23:48:06+00:00 Namjae Jeon linkinjeon@kernel.org 2024-12-05T12:38:47+00:00 b95629435b84b9ecc0c765995204a4d8a913ed52 Increment the session reference count within the lock for lookup to avoid racy issue with session expire. Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-25737 Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> 
Increment the session reference count within the lock for lookup to avoid
racy issue with session expire.

Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-25737
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
ksmbd: fix use-after-free in SMB request handling 2024-11-26T00:58:27+00:00 Yunseong Kim yskelg@gmail.com 2024-11-25T07:45:55+00:00 9a8c5d89d327ff58e9b2517f8a6afb4181d32c6e A race condition exists between SMB request handling in `ksmbd_conn_handler_loop()` and the freeing of `ksmbd_conn` in the workqueue handler `handle_ksmbd_work()`. This leads to a UAF. - KASAN: slab-use-after-free Read in handle_ksmbd_work - KASAN: slab-use-after-free in rtlock_slowlock_locked This race condition arises as follows: - `ksmbd_conn_handler_loop()` waits for `conn->r_count` to reach zero: `wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);` - Meanwhile, `handle_ksmbd_work()` decrements `conn->r_count` using `atomic_dec_return(&conn->r_count)`, and if it reaches zero, calls `ksmbd_conn_free()`, which frees `conn`. - However, after `handle_ksmbd_work()` decrements `conn->r_count`, it may still access `conn->r_count_q` in the following line: `waitqueue_active(&conn->r_count_q)` or `wake_up(&conn->r_count_q)` This results in a UAF, as `conn` has already been freed. The discovery of this UAF can be referenced in the following PR for syzkaller's support for SMB requests. Link: https://github.com/google/syzkaller/pull/5524 Fixes: ee426bfb9d09 ("ksmbd: add refcnt to ksmbd_conn struct") Cc: linux-cifs@vger.kernel.org Cc: stable@vger.kernel.org # v6.6.55+, v6.10.14+, v6.11.3+ Cc: syzkaller@googlegroups.com Signed-off-by: Yunseong Kim <yskelg@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> 
A race condition exists between SMB request handling in
`ksmbd_conn_handler_loop()` and the freeing of `ksmbd_conn` in the
workqueue handler `handle_ksmbd_work()`. This leads to a UAF.
- KASAN: slab-use-after-free Read in handle_ksmbd_work
- KASAN: slab-use-after-free in rtlock_slowlock_locked

This race condition arises as follows:
- `ksmbd_conn_handler_loop()` waits for `conn->r_count` to reach zero:
  `wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);`
- Meanwhile, `handle_ksmbd_work()` decrements `conn->r_count` using
  `atomic_dec_return(&conn->r_count)`, and if it reaches zero, calls
  `ksmbd_conn_free()`, which frees `conn`.
- However, after `handle_ksmbd_work()` decrements `conn->r_count`,
  it may still access `conn->r_count_q` in the following line:
  `waitqueue_active(&conn->r_count_q)` or `wake_up(&conn->r_count_q)`
  This results in a UAF, as `conn` has already been freed.

The discovery of this UAF can be referenced in the following PR for
syzkaller's support for SMB requests.
Link: https://github.com/google/syzkaller/pull/5524

Fixes: ee426bfb9d09 ("ksmbd: add refcnt to ksmbd_conn struct")
Cc: linux-cifs@vger.kernel.org
Cc: stable@vger.kernel.org # v6.6.55+, v6.10.14+, v6.11.3+
Cc: syzkaller@googlegroups.com
Signed-off-by: Yunseong Kim <yskelg@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
ksmbd: use __GFP_RETRY_MAYFAIL 2024-11-26T00:58:02+00:00 Namjae Jeon linkinjeon@kernel.org 2024-11-22T07:33:25+00:00 0066f623bce8f98b69b752ee03d46a5047c281b8 Prefer to report ENOMEM rather than incur the oom for allocations in ksmbd. __GFP_NORETRY could not achieve that, It would fail the allocations just too easily. __GFP_RETRY_MAYFAIL will keep retrying the allocation until there is no more progress and fail the allocation instead go OOM and let the caller to deal with it. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> 
Prefer to report ENOMEM rather than incur the oom for allocations in
ksmbd. __GFP_NORETRY could not achieve that, It would fail the allocations
just too easily. __GFP_RETRY_MAYFAIL will keep retrying the allocation
until there is no more progress and fail the allocation instead go OOM
and let the caller to deal with it.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
ksmbd: check outstanding simultaneous SMB operations 2024-11-05T00:26:38+00:00 Namjae Jeon linkinjeon@kernel.org 2024-11-04T04:43:06+00:00 0a77d947f599b1f39065015bec99390d0c0022ee If Client send simultaneous SMB operations to ksmbd, It exhausts too much memory through the "ksmbd_work_cache”. It will cause OOM issue. ksmbd has a credit mechanism but it can't handle this problem. This patch add the check if it exceeds max credits to prevent this problem by assuming that one smb request consumes at least one credit. Cc: stable@vger.kernel.org # v5.15+ Reported-by: Norbert Szetei <norbert@doyensec.com> Tested-by: Norbert Szetei <norbert@doyensec.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> 
If Client send simultaneous SMB operations to ksmbd, It exhausts too much
memory through the "ksmbd_work_cache”. It will cause OOM issue.
ksmbd has a credit mechanism but it can't handle this problem. This patch
add the check if it exceeds max credits to prevent this problem by assuming
that one smb request consumes at least one credit.

Cc: stable@vger.kernel.org # v5.15+
Reported-by: Norbert Szetei <norbert@doyensec.com>
Tested-by: Norbert Szetei <norbert@doyensec.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
ksmbd: fix slab-use-after-free in smb3_preauth_hash_rsp 2024-11-05T00:26:37+00:00 Namjae Jeon linkinjeon@kernel.org 2024-11-04T04:40:41+00:00 b8fc56fbca7482c1e5c0e3351c6ae78982e25ada ksmbd_user_session_put should be called under smb3_preauth_hash_rsp(). It will avoid freeing session before calling smb3_preauth_hash_rsp(). Cc: stable@vger.kernel.org # v5.15+ Reported-by: Norbert Szetei <norbert@doyensec.com> Tested-by: Norbert Szetei <norbert@doyensec.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> 
ksmbd_user_session_put should be called under smb3_preauth_hash_rsp().
It will avoid freeing session before calling smb3_preauth_hash_rsp().

Cc: stable@vger.kernel.org # v5.15+
Reported-by: Norbert Szetei <norbert@doyensec.com>
Tested-by: Norbert Szetei <norbert@doyensec.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
ksmbd: fix user-after-free from session log off 2024-10-10T02:23:17+00:00 Namjae Jeon linkinjeon@kernel.org 2024-10-08T13:42:57+00:00 7aa8804c0b67b3cb263a472d17f2cb50d7f1a930 There is racy issue between smb2 session log off and smb2 session setup. It will cause user-after-free from session log off. This add session_lock when setting SMB2_SESSION_EXPIRED and referece count to session struct not to free session while it is being used. Cc: stable@vger.kernel.org # v5.15+ Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-25282 Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> 
There is racy issue between smb2 session log off and smb2 session setup.
It will cause user-after-free from session log off.
This add session_lock when setting SMB2_SESSION_EXPIRED and referece
count to session struct not to free session while it is being used.

Cc: stable@vger.kernel.org # v5.15+
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-25282
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
ksmbd: Correct typos in multiple comments across various files 2024-09-26T02:33:22+00:00 Shen Lichuan shenlichuan@vivo.com 2024-09-25T07:43:23+00:00 9e676e571d39eb6189bf6d55a9c401ba2dd13410 Fixed some confusing typos that were currently identified witch codespell, the details are as follows: -in the code comments: fs/smb/common/smb2pdu.h:9: specfication ==> specification fs/smb/common/smb2pdu.h:494: usally ==> usually fs/smb/common/smb2pdu.h:1064: Attrubutes ==> Attributes fs/smb/server/connection.c:28: cleand ==> cleaned fs/smb/server/ksmbd_netlink.h:216: struture ==> structure fs/smb/server/oplock.c:799: conains ==> contains fs/smb/server/oplock.c:1487: containted ==> contained fs/smb/server/server.c:282: proccessing ==> processing fs/smb/server/smb_common.c:491: comforms ==> conforms fs/smb/server/xattr.h:102: ATTRIBUITE ==> ATTRIBUTE Signed-off-by: Shen Lichuan <shenlichuan@vivo.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> 
Fixed some confusing typos that were currently identified witch codespell,
the details are as follows:

-in the code comments:
fs/smb/common/smb2pdu.h:9: specfication ==> specification
fs/smb/common/smb2pdu.h:494: usally ==> usually
fs/smb/common/smb2pdu.h:1064: Attrubutes ==> Attributes
fs/smb/server/connection.c:28: cleand ==> cleaned
fs/smb/server/ksmbd_netlink.h:216: struture ==> structure
fs/smb/server/oplock.c:799: conains ==> contains
fs/smb/server/oplock.c:1487: containted ==> contained
fs/smb/server/server.c:282: proccessing ==> processing
fs/smb/server/smb_common.c:491: comforms ==> conforms
fs/smb/server/xattr.h:102: ATTRIBUITE ==> ATTRIBUTE

Signed-off-by: Shen Lichuan <shenlichuan@vivo.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
smb: move SMB2 Status code to common header file 2024-09-15T15:42:44+00:00 ChenXiaoSong chenxiaosong@kylinos.cn 2024-08-22T08:21:00+00:00 78181a5504a401e421e65d0257a33f904e0e7c29 There are only 4 different definitions between the client and server: - STATUS_SERVER_UNAVAILABLE: from client/smb2status.h - STATUS_FILE_NOT_AVAILABLE: from client/smb2status.h - STATUS_NO_PREAUTH_INTEGRITY_HASH_OVERLAP: from server/smbstatus.h - STATUS_INVALID_LOCK_RANGE: from server/smbstatus.h Rename client/smb2status.h to common/smb2status.h, and merge the 2 different definitions of server to common header file. Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> 
There are only 4 different definitions between the client and server:

  - STATUS_SERVER_UNAVAILABLE: from client/smb2status.h
  - STATUS_FILE_NOT_AVAILABLE: from client/smb2status.h
  - STATUS_NO_PREAUTH_INTEGRITY_HASH_OVERLAP: from server/smbstatus.h
  - STATUS_INVALID_LOCK_RANGE: from server/smbstatus.h

Rename client/smb2status.h to common/smb2status.h, and merge the
2 different definitions of server to common header file.

Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
ksmbd: add durable scavenger timer 2024-07-15T02:45:40+00:00 Namjae Jeon linkinjeon@kernel.org 2024-07-14T23:29:39+00:00 d484d621d40f4a8b8959008802d79bef3609641b Launch ksmbd-durable-scavenger kernel thread to scan durable fps that have not been reclaimed by a client within the configured time. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> 
Launch ksmbd-durable-scavenger kernel thread to scan durable fps that
have not been reclaimed by a client within the configured time.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>