These definitions are exactly the same on both client and server,
so move them to new 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>
Rename get_rfc1002_length() to get_rfc1002_len(), then move duplicate
definitions to common header file.
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>
Merge the struct members of the server and the client:
- req_capabilities: from client
- header_preamble_size: from client
- cap_unicode: from client
- capabilities: from server, rename to req_capabilities
- max_read_size: from server
- max_write_size: from server
- max_trans_size: from server
- max_credits: from server
- create_durable_size: from server
- create_durable_v2_size: from server
- create_mxac_size: from server
- create_disk_id_size: from server
- create_posix_size: from server
Then move duplicate definitions to common header file.
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>
"cifs" is a legacy name, rename it to "smbglob.h" according to
Namjae's suggestions.
Co-developed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: ZhangGuoDong <zhangguodong@kylinos.cn>
Suggested-by: Namjae Jeon <linkinjeon@kernel.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
As the SMB1 and SMB2/3 calc_signature functions are called from separate
sign and verify paths, just call them directly rather than using a function
pointer. The SMB3 calc_signature then jumps to the SMB2 variant if
necessary.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
cc: Paulo Alcantara <pc@manguebit.org>
cc: Shyam Prasad N <sprasad@microsoft.com>
cc: Tom Talpey <tom@talpey.com>
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Fix TCP_Server_Info::credits to be signed, just as echo_credits and
oplock_credits are. This also fixes what ought to get at least a
compilation warning if not an outright error in *get_credits_field() as a
pointer to the unsigned server->credits field is passed back as a pointer
to a signed int.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cifs@vger.kernel.org
Cc: stable@vger.kernel.org
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Acked-by: Pavel Shilovskiy <pshilovskiy@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Now that the SMB client accesses MD5, HMAC-MD5, HMAC-SHA256, and SHA-512
only via the library API and not via crypto_shash, allocating
crypto_shash objects for these algorithms is no longer necessary.
Remove all these allocations, their corresponding kconfig selections,
and their corresponding module soft dependencies.
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
In order to maintain the code more easily, move duplicate definitions to
new common header file.
Co-developed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: ZhangGuoDong <zhangguodong@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>
Don't call ->set_file_info() on open handle to prevent the server from
stopping [cm]time updates automatically as per MS-FSA 2.1.4.17.
Fix this by checking for ATTR_OPEN bit earlier in cifs_setattr() to
prevent ->set_file_info() from being called when opening a file with
O_TRUNC. Do the truncation in ->open() instead.
This also saves two roundtrips when opening a file with O_TRUNC and
there are currently no open handles to be reused.
Before patch:
$ mount.cifs //srv/share /mnt -o ...
$ cd /mnt
$ exec 3>foo; stat -c 'old: %z %y' foo; sleep 2; echo test >&3; exec 3>&-; sleep 2; stat -c 'new: %z %y' foo
old: 2025-10-03 13:26:23.151030500 -0300 2025-10-03 13:26:23.151030500 -0300
new: 2025-10-03 13:26:23.151030500 -0300 2025-10-03 13:26:23.151030500 -0300
After patch:
$ mount.cifs //srv/share /mnt -o ...
$ cd /mnt
$ exec 3>foo; stat -c 'old: %z %y' foo; sleep 2; echo test >&3; exec 3>&-; sleep 2; stat -c 'new: %z %y' foo
$ exec 3>foo; stat -c 'old: %z %y' foo; sleep 2; echo test >&3; exec 3>&-; sleep 2; stat -c 'new: %z %y' foo
old: 2025-10-03 13:28:13.911933800 -0300 2025-10-03 13:28:13.911933800 -0300
new: 2025-10-03 13:28:26.647492700 -0300 2025-10-03 13:28:26.647492700 -0300
Reported-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
This will allow us to move to common functions in future too.
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
This belongs to the SMB layer not to the transport layer, it
just uses the negotiated transport parameters to adjust the
value if needed.
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Rename of open files in SMB2+ has been broken for a very long time,
resulting in data loss as the CIFS client would fail the rename(2)
call with -ENOENT and then removing the target file.
Fix this by implementing ->rename_pending_delete() for SMB2+, which
will rename busy files to random filenames (e.g. silly rename) during
unlink(2) or rename(2), and then marking them to delete-on-close.
Besides, introduce a FIND_WR_NO_PENDING_DELETE flag to prevent open(2)
from reusing open handles that had been marked as delete pending.
Handle it in cifs_get_readable_path() as well.
Reported-by: Jean-Baptiste Denis <jbdenis@pasteur.fr>
Closes: https://marc.info/?i=16aeb380-30d4-4551-9134-4e7d1dc833c0@pasteur.fr
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Cc: Frank Sorenson <sorenson@redhat.com>
Cc: Olga Kornievskaia <okorniev@redhat.com>
Cc: Benjamin Coddington <bcodding@redhat.com>
Cc: Scott Mayhew <smayhew@redhat.com>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
This is step 4/4 of a patch series to fix mid_q_entry memory leaks
caused by race conditions in callback execution.
In compound_send_recv(), when wait_for_response() is interrupted by
signals, the code attempts to cancel pending requests by changing
their callbacks to cifs_cancelled_callback. However, there's a race
condition between signal interruption and network response processing
that causes both mid_q_entry and server buffer leaks:
```
User foreground process cifsd
cifs_readdir
open_cached_dir
cifs_send_recv
compound_send_recv
smb2_setup_request
smb2_mid_entry_alloc
smb2_get_mid_entry
smb2_mid_entry_alloc
mempool_alloc // alloc mid
kref_init(&temp->refcount); // refcount = 1
mid[0]->callback = cifs_compound_callback;
mid[1]->callback = cifs_compound_last_callback;
smb_send_rqst
rc = wait_for_response
wait_event_state TASK_KILLABLE
cifs_demultiplex_thread
allocate_buffers
server->bigbuf = cifs_buf_get()
standard_receive3
->find_mid()
smb2_find_mid
__smb2_find_mid
kref_get(&mid->refcount) // +1
cifs_handle_standard
handle_mid
/* bigbuf will also leak */
mid->resp_buf = server->bigbuf
server->bigbuf = NULL;
dequeue_mid
/* in for loop */
mids[0]->callback
cifs_compound_callback
/* Signal interrupts wait: rc = -ERESTARTSYS */
/* if (... || midQ[i]->mid_state == MID_RESPONSE_RECEIVED) *?
midQ[0]->callback = cifs_cancelled_callback;
cancelled_mid[i] = true;
/* The change comes too late */
mid->mid_state = MID_RESPONSE_READY
release_mid // -1
/* cancelled_mid[i] == true causes mid won't be released
in compound_send_recv cleanup */
/* cifs_cancelled_callback won't executed to release mid */
```
The root cause is that there's a race between callback assignment and
execution.
Fix this by introducing per-mid locking:
- Add spinlock_t mid_lock to struct mid_q_entry
- Add mid_execute_callback() for atomic callback execution
- Use mid_lock in cancellation paths to ensure atomicity
This ensures that either the original callback or the cancellation
callback executes atomically, preventing reference count leaks when
requests are interrupted by signals.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=220404
Fixes: ee258d7915 ("CIFS: Move credit processing to mid callbacks for SMB3")
Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This is step 3/4 of a patch series to fix mid_q_entry memory leaks
caused by race conditions in callback execution.
Replace the mid_flags bitmask with dedicated boolean fields to
simplify locking logic and improve code readability:
- Replace MID_DELETED with bool deleted_from_q
- Replace MID_WAIT_CANCELLED with bool wait_cancelled
- Remove mid_flags field entirely
The new boolean fields have clearer semantics:
- deleted_from_q: whether mid has been removed from pending_mid_q
- wait_cancelled: whether request was cancelled during wait
This change reduces memory usage (from 4-byte bitmask to 2 boolean
flags) and eliminates confusion about which lock protects which
flag bits, preparing for per-mid locking in the next patch.
Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
This is step 2/4 of a patch series to fix mid_q_entry memory leaks
caused by race conditions in callback execution.
Add a dedicated mid_counter_lock to protect current_mid counter,
separating it from mid_queue_lock which protects pending_mid_q
operations. This reduces lock contention and prepares for finer-
grained locking in subsequent patches.
Changes:
- Add TCP_Server_Info->mid_counter_lock spinlock
- Rename CurrentMid to current_mid for consistency
- Use mid_counter_lock to protect current_mid access
- Update locking documentation in cifsglob.h
This separation allows mid allocation to proceed without blocking
queue operations, improving performance under heavy load.
Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
This is step 1/4 of a patch series to fix mid_q_entry memory leaks
caused by race conditions in callback execution.
The current mid_lock name is somewhat ambiguous about what it protects.
To prepare for splitting this lock into separate, more granular locks,
this patch renames mid_lock to mid_queue_lock to clearly indicate its
specific responsibility for protecting the pending_mid_q list and
related queue operations.
No functional changes are made in this patch - it only prepares the
codebase for the lock splitting that follows.
- mid_queue_lock for queue operations
- mid_counter_lock for mid counter operations
- per-mid locks for individual mid state management
Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
SMB3.1.1 POSIX mounts support native symlinks that are created with
IO_REPARSE_TAG_SYMLINK reparse points, so skip the checking of
FILE_SUPPORTS_REPARSE_POINTS as some servers might not have it set.
Cc: linux-cifs@vger.kernel.org
Cc: Ralph Boehme <slow@samba.org>
Cc: David Howells <dhowells@redhat.com>
Cc: <stable@vger.kernel.org>
Reported-by: Matthew Richardson <m.richardson@ed.ac.uk>
Closes: https://marc.info/?i=1124e7cd-6a46-40a6-9f44-b7664a66654b@ed.ac.uk
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
SMB1 already supports querying reparse points and detecting types of
symlink, fifo, socket, block and char.
This change implements the missing part - ability to create a new reparse
points over SMB1. This includes everything which SMB2+ already supports:
- native SMB symlinks and sockets
- NFS style of special files (symlinks, fifos, sockets, char/block devs)
- WSL style of special files (symlinks, fifos, sockets, char/block devs)
Attaching a reparse point to an existing file or directory is done via
SMB1 SMB_COM_NT_TRANSACT/NT_TRANSACT_IOCTL/FSCTL_SET_REPARSE_POINT command
and implemented in a new cifs_create_reparse_inode() function.
This change introduce a new callback ->create_reparse_inode() which creates
a new reperse point file or directory and returns inode. For SMB1 it is
provided via that new cifs_create_reparse_inode() function.
Existing reparse.c code was only slightly updated to call new protocol
callback ->create_reparse_inode() instead of hardcoded SMB2+ function.
This make the whole reparse.c code to work with every SMB dialect.
The original callback ->create_reparse_symlink() is not needed anymore as
the implementation of new create_reparse_symlink() function is dialect
agnostic too. So the link.c code was updated to call that function directly
(and not via callback).
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
When the SMB server reboots and the client immediately accesses the mount
point, a race condition can occur that causes operations to fail with
"Host is down" error.
Reproduction steps:
# Mount SMB share
mount -t cifs //192.168.245.109/TEST /mnt/ -o xxxx
ls /mnt
# Reboot server
ssh root@192.168.245.109 reboot
ssh root@192.168.245.109 /path/to/cifs_server_setup.sh
ssh root@192.168.245.109 systemctl stop firewalld
# Immediate access fails
ls /mnt
ls: cannot access '/mnt': Host is down
# But works if there is a delay
The issue is caused by a race condition between negotiate and reconnect.
The 20-second negotiate timeout mechanism can interfere with the normal
recovery process when both are triggered simultaneously.
ls cifsd
---------------------------------------------------
cifs_getattr
cifs_revalidate_dentry
cifs_get_inode_info
cifs_get_fattr
smb2_query_path_info
smb2_compound_op
SMB2_open_init
smb2_reconnect
cifs_negotiate_protocol
smb2_negotiate
cifs_send_recv
smb_send_rqst
wait_for_response
cifs_demultiplex_thread
cifs_read_from_socket
cifs_readv_from_socket
server_unresponsive
cifs_reconnect
__cifs_reconnect
cifs_abort_connection
mid->mid_state = MID_RETRY_NEEDED
cifs_wake_up_task
cifs_sync_mid_result
// case MID_RETRY_NEEDED
rc = -EAGAIN;
// In smb2_negotiate()
rc = -EHOSTDOWN;
The server_unresponsive() timeout triggers cifs_reconnect(), which aborts
ongoing mid requests and causes the ls command to receive -EAGAIN, leading
to -EHOSTDOWN.
Fix this by introducing a dedicated `neg_start` field to
precisely tracks when the negotiate process begins. The timeout check
now uses this accurate timestamp instead of `lstrp`, ensuring that:
1. Timeout is only triggered after negotiate has actually run for 20s
2. The mechanism doesn't interfere with concurrent recovery processes
3. Uninitialized timestamps (value 0) don't trigger false timeouts
Fixes: 7ccc146546 ("smb: client: fix hang in wait_for_response() for negproto")
Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Fix cifs_signal_cifsd_for_reconnect() to take the correct lock order
and prevent the following deadlock from happening
======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc3-build2+ #1301 Tainted: G S W
------------------------------------------------------
cifsd/6055 is trying to acquire lock:
ffff88810ad56038 (&tcp_ses->srv_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x134/0x200
but task is already holding lock:
ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&ret_buf->chan_lock){+.+.}-{3:3}:
validate_chain+0x1cf/0x270
__lock_acquire+0x60e/0x780
lock_acquire.part.0+0xb4/0x1f0
_raw_spin_lock+0x2f/0x40
cifs_setup_session+0x81/0x4b0
cifs_get_smb_ses+0x771/0x900
cifs_mount_get_session+0x7e/0x170
cifs_mount+0x92/0x2d0
cifs_smb3_do_mount+0x161/0x460
smb3_get_tree+0x55/0x90
vfs_get_tree+0x46/0x180
do_new_mount+0x1b0/0x2e0
path_mount+0x6ee/0x740
do_mount+0x98/0xe0
__do_sys_mount+0x148/0x180
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #1 (&ret_buf->ses_lock){+.+.}-{3:3}:
validate_chain+0x1cf/0x270
__lock_acquire+0x60e/0x780
lock_acquire.part.0+0xb4/0x1f0
_raw_spin_lock+0x2f/0x40
cifs_match_super+0x101/0x320
sget+0xab/0x270
cifs_smb3_do_mount+0x1e0/0x460
smb3_get_tree+0x55/0x90
vfs_get_tree+0x46/0x180
do_new_mount+0x1b0/0x2e0
path_mount+0x6ee/0x740
do_mount+0x98/0xe0
__do_sys_mount+0x148/0x180
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #0 (&tcp_ses->srv_lock){+.+.}-{3:3}:
check_noncircular+0x95/0xc0
check_prev_add+0x115/0x2f0
validate_chain+0x1cf/0x270
__lock_acquire+0x60e/0x780
lock_acquire.part.0+0xb4/0x1f0
_raw_spin_lock+0x2f/0x40
cifs_signal_cifsd_for_reconnect+0x134/0x200
__cifs_reconnect+0x8f/0x500
cifs_handle_standard+0x112/0x280
cifs_demultiplex_thread+0x64d/0xbc0
kthread+0x2f7/0x310
ret_from_fork+0x2a/0x230
ret_from_fork_asm+0x1a/0x30
other info that might help us debug this:
Chain exists of:
&tcp_ses->srv_lock --> &ret_buf->ses_lock --> &ret_buf->chan_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ret_buf->chan_lock);
lock(&ret_buf->ses_lock);
lock(&ret_buf->chan_lock);
lock(&tcp_ses->srv_lock);
*** DEADLOCK ***
3 locks held by cifsd/6055:
#0: ffffffff857de398 (&cifs_tcp_ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x7b/0x200
#1: ffff888119c64060 (&ret_buf->ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x9c/0x200
#2: ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200
Cc: linux-cifs@vger.kernel.org
Reported-by: David Howells <dhowells@redhat.com>
Fixes: d7d7a66aac ("cifs: avoid use of global locks for high contention data")
Reviewed-by: David Howells <dhowells@redhat.com>
Tested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Today, during smb2_reconnect, session_mutex is released as soon as
the tcon is reconnected and is in a good state. However, in case
multichannel is enabled, there is also a query of server interfaces that
follows. We've seen that this query can race with reconnects of other
channels, causing them to step on each other with reconnects.
This change extends the hold of session_mutex till after the query of
server interfaces is complete. In order to avoid recursive smb2_reconnect
checks during query ioctl, this change also introduces a session flag
for sessions where such a query is in progress.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
The lock ordering rules listed as comments in cifsglob.h were
missing some lock details and also the fid_lock.
Updated those notes in this commit.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
According to MS-SMB2 3.2.4.3.8, when opening a file the client must
lookup its parent directory, copy that entry’s LeaseKey into
ParentLeaseKey, and set SMB2_LEASE_FLAG_PARENT_LEASE_KEY_SET.
Extend lease context functions to carry a parent_lease_key and
lease_flags and to add them to the lease context buffer accordingly in
smb3_create_lease_buf. Also add a parent_lease_key field to struct
cifs_fid and lease_flags to cifs_open_parms.
Only applies to the SMB 3.x dialect family.
Fixes: f047390a09 ("CIFS: Add create lease v2 context for SMB3")
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
[MS-CIFS] specification in section 2.2.4.53.1 where is described
SMB_COM_SESSION_SETUP_ANDX Request, for SessionKey field says:
The client MUST set this field to be equal to the SessionKey field in
the SMB_COM_NEGOTIATE Response for this SMB connection.
Linux SMB client currently set this field to zero. This is working fine
against Windows NT SMB servers thanks to [MS-CIFS] product behavior <94>:
Windows NT Server ignores the client's SessionKey.
For compatibility with [MS-CIFS], set this SessionKey field in Session
Setup Request to value retrieved from Negotiate response.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Parsing reparse point buffer is generic for all SMB versions and is already
implemented by global function parse_reparse_point().
Getting reparse point buffer from the SMB response is SMB version specific,
so introduce for it a new callback get_reparse_point_buffer.
This functionality split is needed for followup change - getting reparse
point buffer without parsing it.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Now all NetBIOS session logic is handled in ip_rfc1001_connect() function,
so cleanup is_smb_response() function which contains generic handling of
incoming SMB packets. Note that function is_smb_response() is not used
directly or indirectly (e.g. over cifs_demultiplex_thread() by
ip_rfc1001_connect() function.
Except the Negative Session Response and the Session Keep Alive packet, the
cifs_demultiplex_thread() should not receive any NetBIOS session packets.
And Session Keep Alive packet may be received only when the NetBIOS session
was established by ip_rfc1001_connect() function. So treat any such packet
as error and schedule reconnect.
Negative Session Response packet is returned from Windows SMB server (from
Windows 98 and also from Windows Server 2022) if client sent over port 139
SMB negotiate request without previously establishing a NetBIOS session.
The common scenario is that Negative Session Response packet is returned
for the SMB negotiate packet, which is the first one which SMB client
sends (if it is not establishing a NetBIOS session).
Note that server port 139 may be forwarded and mapped between virtual
machines to different number. And Linux SMB client do not call function
ip_rfc1001_connect() when prot is not 139. So nowadays when using port
mapping or port forwarding between VMs, it is not so uncommon to see this
error.
Currently the logic on Negative Session Response packet changes server port
to 445 and force reconnection. But this logic does not work when using
non-standard port numbers and also does not help if the server on specified
port is requiring establishing a NetBIOS session.
Fix this Negative Session Response logic and instead of changing server
port (on which server does not have to listen), force reconnection with
establishing a NetBIOS session.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Currently SMB client always tries to initialize NetBIOS session when the
server port is 139. This is useful for default cases, but nowadays when
using non-standard routing or testing between VMs, it is common that
servers are listening on non-standard ports.
So add a new mount option -o nbsessinit and -o nonbsessinit which either
forces initialization or disables initialization regardless of server port
number.
This allows Linux SMB client to connect to older SMB1 server listening on
non-standard port, which requires initialization of NetBIOS session, by
using additional mount options -o port= and -o nbsessinit.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Currently, when a SMB connection is reset and renegotiated with the
server, there's no way to update all related mount points with new
negotiated sizes. This is because while superblocks (cifs_sb_info)
maintain references to tree connections (tcon) through tcon_link
structures, there is no reverse mapping from a tcon back to all the
superblocks using it.
This patch adds a bidirectional relationship between tcon and
cifs_sb_info structures by:
1. Adding a cifs_sb_list to tcon structure with appropriate locking
2. Adding tcon_sb_link to cifs_sb_info to join the list
3. Managing the list entries during mount and umount operations
The bidirectional relationship enables future functionality to locate and
update all superblocks connected to a specific tree connection, such as:
- Updating negotiated parameters after reconnection
- Efficiently notifying all affected mounts of capability changes
This is the first part of a series to improve connection resilience
by keeping all mount parameters in sync with server capabilities
after reconnection.
Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
SMB1 protocol supports non-UNICODE (8-bit OEM character set) and
UNICODE (UTF-16) modes.
Linux SMB1 client implements both of them but currently does not allow to
choose non-UNICODE mode when SMB1 server announce UNICODE mode support.
This change adds a new mount option -o nounicode to disable UNICODE mode
and force usage of non-UNICODE (8-bit OEM character set) mode.
This allows to test non-UNICODE implementation of Linux SMB1 client against
any SMB1 server, including modern and recent Windows SMB1 server.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
If a file size has bits 0x410 = ATTR_DIRECTORY | ATTR_REPARSE set
then during queryinfo (stat) the file is regarded as a directory
and subsequent opens can fail. A simple test example is trying
to open any file 1040 bytes long when mounting with "posix"
(SMB3.1.1 POSIX/Linux Extensions).
The cause of this bug is that Attributes field in smb2_file_all_info
struct occupies the same place that EndOfFile field in
smb311_posix_qinfo, and sometimes the latter struct is incorrectly
processed as if it was the first one.
Reported-by: Oleh Nykyforchyn <oleh.nyk@gmail.com>
Tested-by: Oleh Nykyforchyn <oleh.nyk@gmail.com>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.
So, in order to avoid ending up with flexible-array members in the
middle of other structs, we use the `__struct_group()` helper to
separate the flexible arrays from the rest of the members in the
flexible structures. We then use the newly created tagged `struct
smb2_file_link_info_hdr` and `struct smb2_file_rename_info_hdr`
to replace the type of the objects causing trouble: `rename_info`
and `link_info` in `struct smb2_compound_vars`.
We also want to ensure that when new members need to be added to the
flexible structures, they are always included within the newly created
tagged structs. For this, we use `static_assert()`. This ensures that the
memory layout for both the flexible structure and the new tagged struct
is the same after any changes.
So, with these changes, fix 86 of the following warnings:
fs/smb/client/cifsglob.h:2335:36: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
fs/smb/client/cifsglob.h:2334:38: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The netfs library could break down a read request into
multiple subrequests. When multichannel is used, there is
potential to improve performance when each of these
subrequests pick a different channel.
Today we call cifs_pick_channel when the main read request
is initialized in cifs_init_request. This change moves this to
cifs_prepare_read, which is the right place to pick channel since
it gets called for each subrequest.
Interestingly cifs_prepare_write already does channel selection
for individual subreq, but looks like it was missed for read.
This is especially important when multichannel is used with
increased rasize.
In my test setup, with rasize set to 8MB, a sequential read
of large file was taking 11.5s without this change. With the
change, it completed in 9s. The difference is even more signigicant
with bigger rasize.
Cc: <stable@vger.kernel.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
MS-SMB2 section 2.2.13.2.10 specifies that 'epoch' should be a 16-bit
unsigned integer used to track lease state changes. Change the data
type of all instances of 'epoch' from unsigned int to __u16. This
simplifies the epoch change comparisons and makes the code more
compliant with the protocol spec.
Cc: stable@vger.kernel.org
Signed-off-by: Meetakshi Setiya <msetiya@microsoft.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
There are now more servers which advertise support for IAKerb (passthrough
Kerberos authentication via proxy). IAKerb is a public extension industry
standard Kerberos protocol that allows a client without line-of-sight
to a Domain Controller to authenticate. There can be cases where we
would fail to mount if the server only advertises the OID for IAKerb
in SPNEGO/GSSAPI. Add code to allow us to still upcall to userspace
in these cases to obtain the Kerberos ticket.
Signed-off-by: Steve French <stfrench@microsoft.com>
struct FILE_ALL_INFO for level 263 (0x107) used by QPathInfo does not have
any IndexNumber, AccessFlags, IndexNumber1, CurrentByteOffset, Mode or
AlignmentRequirement members. So remove all of them.
Also adjust code in move_cifs_info_to_smb2() function which converts struct
FILE_ALL_INFO to struct smb2_file_all_info.
Fixed content of struct FILE_ALL_INFO was verified that is correct against:
* [MS-CIFS] section 2.2.8.3.10 SMB_QUERY_FILE_ALL_INFO
* Samba server implementation of trans2 query file/path for level 263
* Packet structure tests against Windows SMB servers
This change fixes CIFSSMBQFileInfo() and CIFSSMBQPathInfo() functions which
directly copy received FILE_ALL_INFO network buffers into kernel structures
of FILE_ALL_INFO type.
struct FILE_ALL_INFO is the response structure returned by the SMB server.
So the incorrect definition of this structure can lead to returning bogus
information in stat() call.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
This new mount option allows to completely disable creating new reparse
points. When -o sfu or -o mfsymlinks or -o symlink= is not specified then
creating any special file (fifo, socket, symlink, block and char) will fail
with -EOPNOTSUPP error.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Currently Linux CIFS client creates a new symlink of the first flavor which
is allowed by mount options, parsed in this order: -o (no)mfsymlinks,
-o (no)sfu, -o (no)unix (+ its aliases) and -o reparse=[type].
Introduce a new mount option -o symlink= for explicitly choosing a symlink
flavor. Possible options are:
-o symlink=default - The default behavior, like before this change.
-o symlink=none - Disallow creating a new symlinks
-o symlink=native - Create as native SMB symlink reparse point
-o symlink=unix - Create via SMB1 unix extension command
-o symlink=mfsymlinks - Create as regular file of mfsymlinks format
-o symlink=sfu - Create as regular system file of SFU format
-o symlink=nfs - Create as NFS reparse point
-o symlink=wsl - Create as WSL reparse point
So for example specifying -o sfu,mfsymlinks,symlink=native will allow to
parse symlinks also of SFU and mfsymlinks types (which are disabled by
default unless mount option is explicitly specified), but new symlinks will
be created under native SMB type (which parsing is always enabled).
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Member 'symlink' is part of the union in struct cifs_open_info_data. Its
value is assigned on few places, but is always read through another union
member 'reparse_point'. So to make code more readable, always use only
'reparse_point' member and drop whole union structure. No function change.
Signed-off-by: Pali Rohár <pali@kernel.org>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Linux SMB client already supports more reparse point types but only the
reparse_posix_data is defined in union of struct cifs_open_info_data.
This union is currently used as implicit casting between point types.
With this code style, it hides information that union is used for pointer
casting, and just in mknod_nfs() and posix_reparse_to_fattr() functions.
Other reparse point buffers do not use this kind of casting. So remove
reparse_posix_data from reparse part of struct cifs_open_info_data and for
all cases of reparse buffer use just struct reparse_data_buffer *buf.
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
TCP_Server_Info::leaf_fullpath is allocated in cifs_get_tcp_session()
and never changed afterwards, so there is no need to serialize its
access.
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Old Windows servers will return not fully qualified DFS targets by
default as specified in
MS-DFSC 3.2.5.5 Receiving a Root Referral Request or Link Referral
Request
| Servers SHOULD<30> return fully qualified DNS host names of
| targets in responses to root referral requests and link referral
| requests.
| ...
| <30> Section 3.2.5.5: By default, Windows Server 2003, Windows
| Server 2008, Windows Server 2008 R2, Windows Server 2012, and
| Windows Server 2012 R2 return DNS host names that are not fully
| qualified for targets.
Fix this by converting all NetBIOS host names from DFS targets to
FQDNs and try resolving them first if DNS domain name was provided in
NTLMSSP CHALLENGE_MESSAGE message from previous SMB2_SESSION_SETUP.
This also prevents the client from translating the DFS target
hostnames to another domain depending on the network domain search
order.
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Parse FQDN of the domain in CHALLENGE_MESSAGE message as it's gonna be
useful when mounting DFS shares against old Windows Servers (2012 R2
or earlier) that return not fully qualified hostnames for DFS targets
by default.
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The unmount process (cifs_kill_sb() calling close_all_cached_dirs()) can
race with various cached directory operations, which ultimately results
in dentries not being dropped and these kernel BUGs:
BUG: Dentry ffff88814f37e358{i=1000000000080,n=/} still in use (2) [unmount of cifs cifs]
VFS: Busy inodes after unmount of cifs (cifs)
------------[ cut here ]------------
kernel BUG at fs/super.c:661!
This happens when a cfid is in the process of being cleaned up when, and
has been removed from the cfids->entries list, including:
- Receiving a lease break from the server
- Server reconnection triggers invalidate_all_cached_dirs(), which
removes all the cfids from the list
- The laundromat thread decides to expire an old cfid.
To solve these problems, dropping the dentry is done in queued work done
in a newly-added cfid_put_wq workqueue, and close_all_cached_dirs()
flushes that workqueue after it drops all the dentries of which it's
aware. This is a global workqueue (rather than scoped to a mount), but
the queued work is minimal.
The final cleanup work for cleaning up a cfid is performed via work
queued in the serverclose_wq workqueue; this is done separate from
dropping the dentries so that close_all_cached_dirs() doesn't block on
any server operations.
Both of these queued works expect to invoked with a cfid reference and
a tcon reference to avoid those objects from being freed while the work
is ongoing.
While we're here, add proper locking to close_all_cached_dirs(), and
locking around the freeing of cfid->dentry.
Fixes: ebe98f1447 ("cifs: enable caching of directories for which a lease is held")
Cc: stable@vger.kernel.org
Signed-off-by: Paul Aurich <paul@darkrain42.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
SMB symlink which has SYMLINK_FLAG_RELATIVE set is relative (as opposite of
the absolute) and it can be relative either to the current directory (where
is the symlink stored) or relative to the top level export path. To what it
is relative depends on the first character of the symlink target path.
If the first character is path separator then symlink is relative to the
export, otherwise to the current directory. Linux (and generally POSIX
systems) supports only symlink paths relative to the current directory
where is symlink stored.
Currently if Linux SMB client reads relative SMB symlink with first
character as path separator (slash), it let as is. Which means that Linux
interpret it as absolute symlink pointing from the root (/). But this
location is different than the top level directory of SMB export (unless
SMB export was mounted to the root) and thefore SMB symlinks relative to
the export are interpreted wrongly by Linux SMB client.
Fix this problem. As Linux does not have equivalent of the path relative to
the top of the mount point, convert such symlink target path relative to
the current directory. Do this by prepending "../" pattern N times before
the SMB target path, where N is the number of path separators found in SMB
symlink path.
So for example, if SMB share is mounted to Linux path /mnt/share/, symlink
is stored in file /mnt/share/test/folder1/symlink (so SMB symlink path is
test\folder1\symlink) and SMB symlink target points to \test\folder2\file,
then convert symlink target path to Linux path ../../test/folder2/file.
Deduplicate code for parsing SMB symlinks in native form from functions
smb2_parse_symlink_response() and parse_reparse_native_symlink() into new
function smb2_parse_native_symlink() and pass into this new function a new
full_path parameter from callers, which specify SMB full path where is
symlink stored.
This change fixes resolving of the native Windows symlinks relative to the
top level directory of the SMB share.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
After commit f7f291e14d ("cifs: fix oops during encryption"), the
encryption layer can handle vmalloc'd buffers as well as kmalloc'd
buffers, so there is no need to inefficiently squash request iovs
into a single one to handle padding in compound requests.
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
In the current implementation, the SMB filesystem on a mount point can
trigger upcalls from the kernel to the userspace to enable certain
functionalities like spnego, dns_resolution, amongst others. These upcalls
usually either happen in the context of the mount or in the context of an
application/user. The upcall handler for cifs, cifs.upcall already has
existing code which switches the namespaces to the caller's namespace
before handling the upcall. This behaviour is expected for scenarios like
multiuser mounts, but might not cover all single user scenario with
services such as Kubernetes, where the mount can happen from different
locations such as on the host, from an app container, or a driver pod
which does the mount on behalf of a different pod.
This patch introduces a new mount option called upcall_target, to
customise the upcall behaviour. upcall_target can take 'mount' and 'app'
as possible values. This aids use cases like Kubernetes where the mount
happens on behalf of the application in another container altogether.
Having this new mount option allows the mount command to specify where the
upcall should happen: 'mount' for resolving the upcall to the host
namespace, and 'app' for resolving the upcall to the ns of the calling
thread. This will enable both the scenarios where the Kerberos credentials
can be found on the application namespace or the host namespace to which
just the mount operation is "delegated".
Reviewed-by: Shyam Prasad <shyam.prasad@microsoft.com>
Reviewed-by: Bharath S M <bharathsm@microsoft.com>
Reviewed-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: Ritvik Budhiraja <rbudhiraja@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Due to server permission control, the client does not have access to
the shared root directory, but can access subdirectories normally, so
users usually mount the shared subdirectories directly. In this case,
queryfs should use the actual path instead of the root directory to
avoid the call returning an error (EACCES).
Signed-off-by: wangrong <wangrong@uniontech.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
ChenXiaoSong
ZhangGuoDong
David Howells
Eric Biggers
Paulo Alcantara
Stefan Metzmacher
Wang Zhaolong
Pali Rohár
Shyam Prasad N
Henrique Carvalho
Wang Zhaolong
Steve French
Gustavo A. R. Silva
Meetakshi Setiya
Paulo Alcantara
Paul Aurich
Ritvik Budhiraja
Shen Lichuan
wangrong