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path: root/fs/smb/server/server.c
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2025-03-10ksmbd: prevent connection release during oplock break notificationNamjae Jeon
ksmbd_work could be freed when after connection release. Increment r_count of ksmbd_conn to indicate that requests are not finished yet and to not release the connection. Cc: stable@vger.kernel.org Reported-by: Norbert Szetei <norbert@doyensec.com> Tested-by: Norbert Szetei <norbert@doyensec.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-12-15ksmbd: fix broken transfers when exceeding max simultaneous operationsMarios Makassikis
Since commit 0a77d947f599 ("ksmbd: check outstanding simultaneous SMB operations"), ksmbd enforces a maximum number of simultaneous operations for a connection. The problem is that reaching the limit causes ksmbd to close the socket, and the client has no indication that it should have slowed down. This behaviour can be reproduced by setting "smb2 max credits = 128" (or lower), and transferring a large file (25GB). smbclient fails as below: $ smbclient //192.168.1.254/testshare -U user%pass smb: \> put file.bin cli_push returned NT_STATUS_USER_SESSION_DELETED putting file file.bin as \file.bin smb2cli_req_compound_submit: Insufficient credits. 0 available, 1 needed NT_STATUS_INTERNAL_ERROR closing remote file \file.bin smb: \> smb2cli_req_compound_submit: Insufficient credits. 0 available, 1 needed Windows clients fail with 0x8007003b (with smaller files even). Fix this by delaying reading from the socket until there's room to allocate a request. This effectively applies backpressure on the client, so the transfer completes, albeit at a slower rate. Fixes: 0a77d947f599 ("ksmbd: check outstanding simultaneous SMB operations") Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-12-10ksmbd: fix racy issue from session lookup and expireNamjae Jeon
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>
2024-11-25ksmbd: fix use-after-free in SMB request handlingYunseong Kim
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>
2024-11-25ksmbd: use __GFP_RETRY_MAYFAILNamjae Jeon
Prefer to report ENOMEM rather than incur the oom for allocations in ksmbd. __GFP_NORETRY could not achieve that, It would fail the allocations just too easily. __GFP_RETRY_MAYFAIL will keep retrying the allocation until there is no more progress and fail the allocation instead go OOM and let the caller to deal with it. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-11-05ksmbd: check outstanding simultaneous SMB operationsNamjae Jeon
If Client send simultaneous SMB operations to ksmbd, It exhausts too much memory through the "ksmbd_work_cache”. It will cause OOM issue. ksmbd has a credit mechanism but it can't handle this problem. This patch add the check if it exceeds max credits to prevent this problem by assuming that one smb request consumes at least one credit. Cc: stable@vger.kernel.org # v5.15+ Reported-by: Norbert Szetei <norbert@doyensec.com> Tested-by: Norbert Szetei <norbert@doyensec.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-11-05ksmbd: fix slab-use-after-free in smb3_preauth_hash_rspNamjae Jeon
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>
2024-10-09ksmbd: fix user-after-free from session log offNamjae Jeon
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>
2024-09-25ksmbd: Correct typos in multiple comments across various filesShen Lichuan
Fixed some confusing typos that were currently identified witch codespell, the details are as follows: -in the code comments: fs/smb/common/smb2pdu.h:9: specfication ==> specification fs/smb/common/smb2pdu.h:494: usally ==> usually fs/smb/common/smb2pdu.h:1064: Attrubutes ==> Attributes fs/smb/server/connection.c:28: cleand ==> cleaned fs/smb/server/ksmbd_netlink.h:216: struture ==> structure fs/smb/server/oplock.c:799: conains ==> contains fs/smb/server/oplock.c:1487: containted ==> contained fs/smb/server/server.c:282: proccessing ==> processing fs/smb/server/smb_common.c:491: comforms ==> conforms fs/smb/server/xattr.h:102: ATTRIBUITE ==> ATTRIBUTE Signed-off-by: Shen Lichuan <shenlichuan@vivo.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-09-15smb: move SMB2 Status code to common header fileChenXiaoSong
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>
2024-07-14ksmbd: add durable scavenger timerNamjae Jeon
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>
2024-04-19ksmbd: fix slab-out-of-bounds in smb2_allocate_rsp_bufNamjae Jeon
If ->ProtocolId is SMB2_TRANSFORM_PROTO_NUM, smb2 request size validation could be skipped. if request size is smaller than sizeof(struct smb2_query_info_req), slab-out-of-bounds read can happen in smb2_allocate_rsp_buf(). This patch allocate response buffer after decrypting transform request. smb3_decrypt_req() will validate transform request size and avoid slab-out-of-bound in smb2_allocate_rsp_buf(). Reported-by: Norbert Szetei <norbert@doyensec.com> Cc: stable@vger.kernel.org Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-03-18ksmbd: remove module versionNamjae Jeon
ksmbd module version marking is not needed. Since there is a Linux kernel version, there is no point in increasing it anymore. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-10-04ksmbd: fix race condition between tree conn lookup and disconnectNamjae Jeon
if thread A in smb2_write is using work-tcon, other thread B use smb2_tree_disconnect free the tcon, then thread A will use free'd tcon. Time + Thread A | Thread A smb2_write | smb2_tree_disconnect | | | kfree(tree_conn) | // UAF! | work->tcon->share_conf | + This patch add state, reference count and lock for tree conn to fix race condition issue. Reported-by: luosili <rootlab@huawei.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-09-21ksmbd: return invalid parameter error response if smb2 request is invalidNamjae Jeon
If smb2 request from client is invalid, The following kernel oops could happen. The patch e2b76ab8b5c9: "ksmbd: add support for read compound" leads this issue. When request is invalid, It doesn't set anything in the response buffer. This patch add missing set invalid parameter error response. [ 673.085542] ksmbd: cli req too short, len 184 not 142. cmd:5 mid:109 [ 673.085580] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 673.085591] #PF: supervisor read access in kernel mode [ 673.085600] #PF: error_code(0x0000) - not-present page [ 673.085608] PGD 0 P4D 0 [ 673.085620] Oops: 0000 [#1] PREEMPT SMP NOPTI [ 673.085631] CPU: 3 PID: 1039 Comm: kworker/3:0 Not tainted 6.6.0-rc2-tmt #16 [ 673.085643] Hardware name: AZW U59/U59, BIOS JTKT001 05/05/2022 [ 673.085651] Workqueue: ksmbd-io handle_ksmbd_work [ksmbd] [ 673.085719] RIP: 0010:ksmbd_conn_write+0x68/0xc0 [ksmbd] [ 673.085808] RAX: 0000000000000000 RBX: ffff88811ade4f00 RCX: 0000000000000000 [ 673.085817] RDX: 0000000000000000 RSI: ffff88810c2a9780 RDI: ffff88810c2a9ac0 [ 673.085826] RBP: ffffc900005e3e00 R08: 0000000000000000 R09: 0000000000000000 [ 673.085834] R10: ffffffffa3168160 R11: 63203a64626d736b R12: ffff8881057c8800 [ 673.085842] R13: ffff8881057c8820 R14: ffff8882781b2380 R15: ffff8881057c8800 [ 673.085852] FS: 0000000000000000(0000) GS:ffff888278180000(0000) knlGS:0000000000000000 [ 673.085864] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 673.085872] CR2: 0000000000000000 CR3: 000000015b63c000 CR4: 0000000000350ee0 [ 673.085883] Call Trace: [ 673.085890] <TASK> [ 673.085900] ? show_regs+0x6a/0x80 [ 673.085916] ? __die+0x25/0x70 [ 673.085926] ? page_fault_oops+0x154/0x4b0 [ 673.085938] ? tick_nohz_tick_stopped+0x18/0x50 [ 673.085954] ? __irq_work_queue_local+0xba/0x140 [ 673.085967] ? do_user_addr_fault+0x30f/0x6c0 [ 673.085979] ? exc_page_fault+0x79/0x180 [ 673.085992] ? asm_exc_page_fault+0x27/0x30 [ 673.086009] ? ksmbd_conn_write+0x68/0xc0 [ksmbd] [ 673.086067] ? ksmbd_conn_write+0x46/0xc0 [ksmbd] [ 673.086123] handle_ksmbd_work+0x28d/0x4b0 [ksmbd] [ 673.086177] process_one_work+0x178/0x350 [ 673.086193] ? __pfx_worker_thread+0x10/0x10 [ 673.086202] worker_thread+0x2f3/0x420 [ 673.086210] ? _raw_spin_unlock_irqrestore+0x27/0x50 [ 673.086222] ? __pfx_worker_thread+0x10/0x10 [ 673.086230] kthread+0x103/0x140 [ 673.086242] ? __pfx_kthread+0x10/0x10 [ 673.086253] ret_from_fork+0x39/0x60 [ 673.086263] ? __pfx_kthread+0x10/0x10 [ 673.086274] ret_from_fork_asm+0x1b/0x30 Fixes: e2b76ab8b5c9 ("ksmbd: add support for read compound") Reported-by: Tom Talpey <tom@talpey.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-09-03ksmbd: remove experimental warningSteve French
ksmbd has made significant improvements over the past two years and is regularly tested and used. Remove the experimental warning. Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-08-29ksmbd: add support for read compoundNamjae Jeon
MacOS sends a compound request including read to the server (e.g. open-read-close). So far, ksmbd has not handled read as a compound request. For compatibility between ksmbd and an OS that supports SMB, This patch provides compound support for read requests. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-07-23ksmbd: fix out of bounds in init_smb2_rsp_hdr()Namjae Jeon
If client send smb2 negotiate request and then send smb1 negotiate request, init_smb2_rsp_hdr is called for smb1 negotiate request since need_neg is set to false. This patch ignore smb1 packets after ->need_neg is set to false. Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-21541 Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-06-16ksmbd: validate session id and tree id in the compound requestNamjae Jeon
This patch validate session id and tree id in compound request. If first operation in the compound is SMB2 ECHO request, ksmbd bypass session and tree validation. So work->sess and work->tcon could be NULL. If secound request in the compound access work->sess or tcon, It cause NULL pointer dereferecing error. Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-21165 Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-05-24smb: move client and server files to common directory fs/smbSteve French
Move CIFS/SMB3 related client and server files (cifs.ko and ksmbd.ko and helper modules) to new fs/smb subdirectory: fs/cifs --> fs/smb/client fs/ksmbd --> fs/smb/server fs/smbfs_common --> fs/smb/common Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
generated by cgit (git 2.34.1) at 2025-07-25 16:07:09 +0000