From dfd046d0ced19b6ff5f11ec4ceab0a83de924771 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Thu, 15 Aug 2024 08:56:35 +0900 Subject: [PATCH 1/4] ksmbd: Use unsafe_memcpy() for ntlm_negotiate rsp buffer is allocated larger than spnego_blob from smb2_allocate_rsp_buf(). Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/smb2pdu.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 2df1354288e68..3f4c56a10a86f 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -1370,7 +1370,8 @@ static int ntlm_negotiate(struct ksmbd_work *work, } sz = le16_to_cpu(rsp->SecurityBufferOffset); - memcpy((char *)&rsp->hdr.ProtocolId + sz, spnego_blob, spnego_blob_len); + unsafe_memcpy((char *)&rsp->hdr.ProtocolId + sz, spnego_blob, spnego_blob_len, + /* alloc is larger than blob, see smb2_allocate_rsp_buf() */); rsp->SecurityBufferLength = cpu_to_le16(spnego_blob_len); out: @@ -1453,7 +1454,9 @@ static int ntlm_authenticate(struct ksmbd_work *work, return -ENOMEM; sz = le16_to_cpu(rsp->SecurityBufferOffset); - memcpy((char *)&rsp->hdr.ProtocolId + sz, spnego_blob, spnego_blob_len); + unsafe_memcpy((char *)&rsp->hdr.ProtocolId + sz, spnego_blob, + spnego_blob_len, + /* alloc is larger than blob, see smb2_allocate_rsp_buf() */); rsp->SecurityBufferLength = cpu_to_le16(spnego_blob_len); kfree(spnego_blob); } From 76e98a158b207771a6c9a0de0a60522a446a3447 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Sat, 17 Aug 2024 14:03:49 +0900 Subject: [PATCH 2/4] ksmbd: fix race condition between destroy_previous_session() and smb2 operations() If there is ->PreviousSessionId field in the session setup request, The session of the previous connection should be destroyed. During this, if the smb2 operation requests in the previous session are being processed, a racy issue could happen with ksmbd_destroy_file_table(). This patch sets conn->status to KSMBD_SESS_NEED_RECONNECT to block incoming operations and waits until on-going operations are complete (i.e. idle) before desctorying the previous session. Fixes: c8efcc786146 ("ksmbd: add support for durable handles v1/v2") Cc: stable@vger.kernel.org # v6.6+ Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-25040 Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/connection.c | 34 ++++++++++++++++++++++++++++++- fs/smb/server/connection.h | 3 ++- fs/smb/server/mgmt/user_session.c | 9 ++++++++ fs/smb/server/smb2pdu.c | 2 +- 4 files changed, 45 insertions(+), 3 deletions(-) diff --git a/fs/smb/server/connection.c b/fs/smb/server/connection.c index 09e1e7771592f..7889df8112b4e 100644 --- a/fs/smb/server/connection.c +++ b/fs/smb/server/connection.c @@ -165,11 +165,43 @@ void ksmbd_all_conn_set_status(u64 sess_id, u32 status) up_read(&conn_list_lock); } -void ksmbd_conn_wait_idle(struct ksmbd_conn *conn, u64 sess_id) +void ksmbd_conn_wait_idle(struct ksmbd_conn *conn) { wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2); } +int ksmbd_conn_wait_idle_sess_id(struct ksmbd_conn *curr_conn, u64 sess_id) +{ + struct ksmbd_conn *conn; + int rc, retry_count = 0, max_timeout = 120; + int rcount = 1; + +retry_idle: + if (retry_count >= max_timeout) + return -EIO; + + down_read(&conn_list_lock); + list_for_each_entry(conn, &conn_list, conns_list) { + if (conn->binding || xa_load(&conn->sessions, sess_id)) { + if (conn == curr_conn) + rcount = 2; + if (atomic_read(&conn->req_running) >= rcount) { + rc = wait_event_timeout(conn->req_running_q, + atomic_read(&conn->req_running) < rcount, + HZ); + if (!rc) { + up_read(&conn_list_lock); + retry_count++; + goto retry_idle; + } + } + } + } + up_read(&conn_list_lock); + + return 0; +} + int ksmbd_conn_write(struct ksmbd_work *work) { struct ksmbd_conn *conn = work->conn; diff --git a/fs/smb/server/connection.h b/fs/smb/server/connection.h index 5c2845e47cf2d..5b947175c048e 100644 --- a/fs/smb/server/connection.h +++ b/fs/smb/server/connection.h @@ -145,7 +145,8 @@ extern struct list_head conn_list; extern struct rw_semaphore conn_list_lock; bool ksmbd_conn_alive(struct ksmbd_conn *conn); -void ksmbd_conn_wait_idle(struct ksmbd_conn *conn, u64 sess_id); +void ksmbd_conn_wait_idle(struct ksmbd_conn *conn); +int ksmbd_conn_wait_idle_sess_id(struct ksmbd_conn *curr_conn, u64 sess_id); struct ksmbd_conn *ksmbd_conn_alloc(void); void ksmbd_conn_free(struct ksmbd_conn *conn); bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c); diff --git a/fs/smb/server/mgmt/user_session.c b/fs/smb/server/mgmt/user_session.c index 162a12685d2c9..99416ce9f5018 100644 --- a/fs/smb/server/mgmt/user_session.c +++ b/fs/smb/server/mgmt/user_session.c @@ -311,6 +311,7 @@ void destroy_previous_session(struct ksmbd_conn *conn, { struct ksmbd_session *prev_sess; struct ksmbd_user *prev_user; + int err; down_write(&sessions_table_lock); down_write(&conn->session_lock); @@ -325,8 +326,16 @@ void destroy_previous_session(struct ksmbd_conn *conn, memcmp(user->passkey, prev_user->passkey, user->passkey_sz)) goto out; + ksmbd_all_conn_set_status(id, KSMBD_SESS_NEED_RECONNECT); + err = ksmbd_conn_wait_idle_sess_id(conn, id); + if (err) { + ksmbd_all_conn_set_status(id, KSMBD_SESS_NEED_NEGOTIATE); + goto out; + } + ksmbd_destroy_file_table(&prev_sess->file_table); prev_sess->state = SMB2_SESSION_EXPIRED; + ksmbd_all_conn_set_status(id, KSMBD_SESS_NEED_NEGOTIATE); ksmbd_launch_ksmbd_durable_scavenger(); out: up_write(&conn->session_lock); diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 3f4c56a10a86f..cb7f487c96af8 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -2213,7 +2213,7 @@ int smb2_session_logoff(struct ksmbd_work *work) ksmbd_conn_unlock(conn); ksmbd_close_session_fds(work); - ksmbd_conn_wait_idle(conn, sess_id); + ksmbd_conn_wait_idle(conn); /* * Re-lookup session to validate if session is deleted From 4fdd8664c8a94411a01d11d5ed2f083f105f570a Mon Sep 17 00:00:00 2001 From: Victor Timofei Date: Fri, 16 Aug 2024 22:24:52 +0300 Subject: [PATCH 3/4] ksmbd: fix spelling mistakes in documentation There are a couple of spelling mistakes in the documentation. This patch fixes them. Signed-off-by: Victor Timofei Acked-by: Namjae Jeon Signed-off-by: Steve French --- Documentation/filesystems/smb/ksmbd.rst | 26 ++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/Documentation/filesystems/smb/ksmbd.rst b/Documentation/filesystems/smb/ksmbd.rst index 6b30e43a0d11f..67cb68ea6e688 100644 --- a/Documentation/filesystems/smb/ksmbd.rst +++ b/Documentation/filesystems/smb/ksmbd.rst @@ -13,7 +13,7 @@ KSMBD architecture The subset of performance related operations belong in kernelspace and the other subset which belong to operations which are not really related with performance in userspace. So, DCE/RPC management that has historically resulted -into number of buffer overflow issues and dangerous security bugs and user +into a number of buffer overflow issues and dangerous security bugs and user account management are implemented in user space as ksmbd.mountd. File operations that are related with performance (open/read/write/close etc.) in kernel space (ksmbd). This also allows for easier integration with VFS @@ -24,8 +24,8 @@ ksmbd (kernel daemon) When the server daemon is started, It starts up a forker thread (ksmbd/interface name) at initialization time and open a dedicated port 445 -for listening to SMB requests. Whenever new clients make request, Forker -thread will accept the client connection and fork a new thread for dedicated +for listening to SMB requests. Whenever new clients make a request, the Forker +thread will accept the client connection and fork a new thread for a dedicated communication channel between the client and the server. It allows for parallel processing of SMB requests(commands) from clients as well as allowing for new clients to make new connections. Each instance is named ksmbd/1~n(port number) @@ -34,12 +34,12 @@ thread can decide to pass through the commands to the user space (ksmbd.mountd), currently DCE/RPC commands are identified to be handled through the user space. To further utilize the linux kernel, it has been chosen to process the commands as workitems and to be executed in the handlers of the ksmbd-io kworker threads. -It allows for multiplexing of the handlers as the kernel take care of initiating +It allows for multiplexing of the handlers as the kernel takes care of initiating extra worker threads if the load is increased and vice versa, if the load is -decreased it destroys the extra worker threads. So, after connection is -established with client. Dedicated ksmbd/1..n(port number) takes complete +decreased it destroys the extra worker threads. So, after the connection is +established with the client. Dedicated ksmbd/1..n(port number) takes complete ownership of receiving/parsing of SMB commands. Each received command is worked -in parallel i.e., There can be multiple clients commands which are worked in +in parallel i.e., there can be multiple client commands which are worked in parallel. After receiving each command a separated kernel workitem is prepared for each command which is further queued to be handled by ksmbd-io kworkers. So, each SMB workitem is queued to the kworkers. This allows the benefit of load @@ -49,9 +49,9 @@ performance by handling client commands in parallel. ksmbd.mountd (user space daemon) -------------------------------- -ksmbd.mountd is userspace process to, transfer user account and password that +ksmbd.mountd is a userspace process to, transfer the user account and password that are registered using ksmbd.adduser (part of utils for user space). Further it -allows sharing information parameters that parsed from smb.conf to ksmbd in +allows sharing information parameters that are parsed from smb.conf to ksmbd in kernel. For the execution part it has a daemon which is continuously running and connected to the kernel interface using netlink socket, it waits for the requests (dcerpc and share/user info). It handles RPC calls (at a minimum few @@ -124,7 +124,7 @@ How to run 1. Download ksmbd-tools(https://github.com/cifsd-team/ksmbd-tools/releases) and compile them. - - Refer README(https://github.com/cifsd-team/ksmbd-tools/blob/master/README.md) + - Refer to README(https://github.com/cifsd-team/ksmbd-tools/blob/master/README.md) to know how to use ksmbd.mountd/adduser/addshare/control utils $ ./autogen.sh @@ -133,7 +133,7 @@ How to run 2. Create /usr/local/etc/ksmbd/ksmbd.conf file, add SMB share in ksmbd.conf file. - - Refer ksmbd.conf.example in ksmbd-utils, See ksmbd.conf manpage + - Refer to ksmbd.conf.example in ksmbd-utils, See ksmbd.conf manpage for details to configure shares. $ man ksmbd.conf @@ -145,7 +145,7 @@ How to run $ man ksmbd.adduser $ sudo ksmbd.adduser -a -4. Insert ksmbd.ko module after build your kernel. No need to load module +4. Insert the ksmbd.ko module after you build your kernel. No need to load the module if ksmbd is built into the kernel. - Set ksmbd in menuconfig(e.g. $ make menuconfig) @@ -175,7 +175,7 @@ Each layer 1. Enable all component prints # sudo ksmbd.control -d "all" -2. Enable one of components (smb, auth, vfs, oplock, ipc, conn, rdma) +2. Enable one of the components (smb, auth, vfs, oplock, ipc, conn, rdma) # sudo ksmbd.control -d "smb" 3. Show what prints are enabled. From 7c525dddbee71880e654ad44f3917787a4f6042c Mon Sep 17 00:00:00 2001 From: Thorsten Blum Date: Fri, 16 Aug 2024 19:33:39 +0200 Subject: [PATCH 4/4] ksmbd: Replace one-element arrays with flexible-array members Replace the deprecated one-element arrays with flexible-array members in the structs filesystem_attribute_info and filesystem_device_info. There are no binary differences after this conversion. Link: https://github.com/KSPP/linux/issues/79 Signed-off-by: Thorsten Blum Reviewed-by: Gustavo A. R. Silva Acked-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/smb2pdu.c | 4 ++-- fs/smb/server/smb_common.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index cb7f487c96af8..0bc9edf22ba40 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -5360,7 +5360,7 @@ static int smb2_get_info_filesystem(struct ksmbd_work *work, "NTFS", PATH_MAX, conn->local_nls, 0); len = len * 2; info->FileSystemNameLen = cpu_to_le32(len); - sz = sizeof(struct filesystem_attribute_info) - 2 + len; + sz = sizeof(struct filesystem_attribute_info) + len; rsp->OutputBufferLength = cpu_to_le32(sz); break; } @@ -5386,7 +5386,7 @@ static int smb2_get_info_filesystem(struct ksmbd_work *work, len = len * 2; info->VolumeLabelSize = cpu_to_le32(len); info->Reserved = 0; - sz = sizeof(struct filesystem_vol_info) - 2 + len; + sz = sizeof(struct filesystem_vol_info) + len; rsp->OutputBufferLength = cpu_to_le32(sz); break; } diff --git a/fs/smb/server/smb_common.h b/fs/smb/server/smb_common.h index 4a3148b0167f5..cc1d6dfe29d56 100644 --- a/fs/smb/server/smb_common.h +++ b/fs/smb/server/smb_common.h @@ -213,7 +213,7 @@ struct filesystem_attribute_info { __le32 Attributes; __le32 MaxPathNameComponentLength; __le32 FileSystemNameLen; - __le16 FileSystemName[1]; /* do not have to save this - get subset? */ + __le16 FileSystemName[]; /* do not have to save this - get subset? */ } __packed; struct filesystem_device_info { @@ -226,7 +226,7 @@ struct filesystem_vol_info { __le32 SerialNumber; __le32 VolumeLabelSize; __le16 Reserved; - __le16 VolumeLabel[1]; + __le16 VolumeLabel[]; } __packed; struct filesystem_info {