We had cases in the previous patch where we were sending the security
descriptor context on SMB3 open (file create) in cases when we hadn't
mounted with with "modefromsid" mount option.
Add check for that mount flag before calling ad_sd_context in
open init.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
When using the special SID to store the mode bits in an ACE (See
http://technet.microsoft.com/en-us/library/hh509017(v=ws.10).aspx)
which is enabled with mount parm "modefromsid" we were not
passing in the mode via SMB3 create (although chmod was enabled).
SMB3 create allows a security descriptor context to be passed
in (which is more atomic and thus preferable to setting the mode
bits after create via a setinfo).
This patch enables setting the mode bits on create when using
modefromsid mount option. In addition it fixes an endian
error in the definition of the Control field flags in the SMB3
security descriptor. It also makes the ACE type of the special
SID better match the documentation (and behavior of servers
which use this to store mode bits in SMB3 ACLs).
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Since timestamps on files on most servers can be updated at
close, and since timestamps on our dentries default to one
second we can have stale timestamps in some common cases
(e.g. open, write, close, stat, wait one second, stat - will
show different mtime for the first and second stat).
The SMB2/SMB3 protocol allows querying timestamps at close
so add the code to request timestamp and attr information
(which is cheap for the server to provide) to be returned
when a file is closed (it is not needed for the many
paths that call SMB2_close that are from compounded
query infos and close nor is it needed for some of
the cases where a directory close immediately follows a
directory open.
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
close was relayered to allow passing in an async flag which
is no longer needed in this path. Remove the unneeded parameter
"flags" passed in on close.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
The pointer pneg_ctxt is being initialized with a value that is never
read and it is being updated later with a new value. The assignment
is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We used to skip reconnects on all SMB2_IOCTL commands due to SMB3+
FSCTL_VALIDATE_NEGOTIATE_INFO - which made sense since we're still
establishing a SMB session.
However, when refresh_cache_worker() calls smb2_get_dfs_refer() and
we're under reconnect, SMB2_ioctl() will not be able to get a proper
status error (e.g. -EHOSTDOWN in case we failed to reconnect) but an
-EAGAIN from cifs_send_recv() thus looping forever in
refresh_cache_worker().
Fixes: e99c63e4d8 ("SMB3: Fix deadlock in validate negotiate hits reconnect")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Suggested-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
After doing mount() successfully we call cifs_try_adding_channels()
which will open as many channels as it can.
Channels are closed when the master session is closed.
The master connection becomes the first channel.
,-------------> global cifs_tcp_ses_list <-------------------------.
| |
'- TCP_Server_Info <--> TCP_Server_Info <--> TCP_Server_Info <-'
(master con) (chan#1 con) (chan#2 con)
| ^ ^ ^
v '--------------------|--------------------'
cifs_ses |
- chan_count = 3 |
- chans[] ---------------------'
- smb3signingkey[]
(master signing key)
Note how channel connections don't have sessions. That's because
cifs_ses can only be part of one linked list (list_head are internal
to the elements).
For signing keys, each channel has its own signing key which must be
used only after the channel has been bound. While it's binding it must
use the master session signing key.
For encryption keys, since channel connections do not have sessions
attached we must now find matching session by looping over all sessions
in smb2_get_enc_key().
Each channel is opened like a regular server connection but at the
session setup request step it must set the
SMB2_SESSION_REQ_FLAG_BINDING flag and use the session id to bind to.
Finally, while sending in compound_send_recv() for requests that
aren't negprot, ses-setup or binding related, use a channel by cycling
through the available ones (round-robin).
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Currently a lot of the code to initialize a connection & session uses
the cifs_ses as input. But depending on if we are opening a new session
or a new channel we need to use different server pointers.
Add a "binding" flag in cifs_ses and a helper function that returns
the server ptr a session should use (only in the sess establishment
code path).
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
If Close command is interrupted before sending a request
to the server the client ends up leaking an open file
handle. This wastes server resources and can potentially
block applications that try to remove the file or any
directory containing this file.
Fix this by putting the close command into a worker queue,
so another thread retries it later.
Cc: Stable <stable@vger.kernel.org>
Tested-by: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Message was intended only for developer temporary build
In addition cleanup two minor warnings noticed by Coverity
and a trivial change to workaround a sparse warning
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Now that sparse has been fixed, it spotted a couple recent minor
endian errors (and removed one additional sparse warning).
Thanks to Luc Van Oostenryck for his help fixing sparse.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
We need to populate an ACL (security descriptor open context)
on file and directory correct. This patch passes in the
mode. Followon patch will build the open context and the
security descriptor (from the mode) that goes in the open
context.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Fix sparse warnings:
fs/cifs/smb2pdu.c:3200:1: warning: symbol 'SMB2_notify_init' was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We were not bumping up the "open on server" (num_remote_opens)
counter (in some cases) on opens of the share root so
could end up showing as a negative value.
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
SMB3 change notify is important to allow applications to wait
on directory change events of different types (e.g. adding
and deleting files from others systems). Add worker functions
for this.
Acked-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
In some cases to work around server bugs or performance
problems it can be helpful to be able to disable requesting
SMB2.1/SMB3 leases on a particular mount (not to all servers
and all shares we are mounted to). Add new mount parm
"nolease" which turns off requesting leases on directory
or file opens. Currently the only way to disable leases is
globally through a module load parameter. This is more
granular.
Suggested-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
When a share is deleted, returning EIO is confusing and no useful
information is logged. Improve the handling of this case by
at least logging a better error for this (and also mapping the error
differently to EREMCHG). See e.g. the new messages that would be logged:
[55243.639530] server share \\192.168.1.219\scratch deleted
[55243.642568] CIFS VFS: \\192.168.1.219\scratch BAD_NETWORK_NAME: \\192.168.1.219\scratch
In addition for the case where a share is deleted and then recreated
with the same name, have now fixed that so it works. This is sometimes
done for example, because the admin had to move a share to a different,
bigger local drive when a share is running low on space.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Where we have a tcon available we can log \\server\share as part
of the message. Only do this for the VFS log level.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Code cleanup in the 5.1 kernel changed the array
passed into signing verification on large reads leading
to warning messages being logged when copying files to local
systems from remote.
SMB signature verification returned error = -5
This changeset fixes verification of SMB3 signatures of large
reads.
Suggested-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
The assignment of pointer server dereferences pointer ses, however,
this dereference occurs before ses is null checked and hence we
have a potential null pointer dereference. Fix this by only
dereferencing ses after it has been null checked.
Addresses-Coverity: ("Dereference before null check")
Fixes: 2808c6639104 ("cifs: add new debugging macro cifs_server_dbg")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
which can be used from contexts where we have a TCP_Server_Info *server.
This new macro will prepend the debugging string with "Server:<servername> "
which will help when debugging issues on hosts with many cifs connections
to several different servers.
Convert a bunch of cifs_dbg(VFS) calls to cifs_server_dbg(VFS)
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
It is not null terminated (length was off by two).
Also see similar change to Samba:
https://gitlab.com/samba-team/samba/merge_requests/666
Reported-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Variable rc is being initialized with a value that is never read
and rc is being re-assigned a little later on. The assignment is
redundant and hence can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Create smb2_flush_init() and smb2_flush_free() so we can use the flush command
in compounds.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We had a report of a server which did not do a DFS referral
because the session setup Capabilities field was set to 0
(unlike negotiate protocol where we set CAP_DFS). Better to
send it session setup in the capabilities as well (this also
more closely matches Windows client behavior).
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Currently we skip SMB2_TREE_CONNECT command when checking during
reconnect because Tree Connect happens when establishing
an SMB session. For SMB 3.0 protocol version the code also calls
validate negotiate which results in SMB2_IOCL command being sent
over the wire. This may deadlock on trying to acquire a mutex when
checking for reconnect. Fix this by skipping SMB2_IOCL command
when doing the reconnect check.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
We can cut one third of the traffic on open by not querying the
inode number explicitly via SMB3 query_info since it is now
returned on open in the qfid context.
This is better in multiple ways, and
speeds up file open about 10% (more if network is slow).
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We can cut the number of roundtrips on open (may also
help some rename cases as well) by returning the inode
number in the SMB2 open request itself instead of
querying it afterwards via a query FILE_INTERNAL_INFO.
This should significantly improve the performance of
posix open.
Add SMB2_CREATE_QUERY_ON_DISK_ID create context request
on open calls so that when server supports this we
can save a roundtrip for QUERY_INFO on every open.
Follow on patch will add the response processing for
SMB2_CREATE_QUERY_ON_DISK_ID context and optimize
smb2_open_file to avoid the extra network roundtrip
on every posix open. This patch adds the context on
SMB2/SMB3 open requests.
Signed-off-by: Steve French <stfrench@microsoft.com>
Since in theory a server could respond with compressed read
responses even if not requested on read request (assuming that
a compression negcontext is sent in negotiate protocol) - do
not send compression information during negotiate protocol
unless the user asks for compression explicitly (compression
is experimental), and add a mount warning that compression
is experimental.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
GCM is faster. Request it during negotiate protocol.
Followon patch will add callouts to GCM crypto
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Use kmemdup rather than duplicating its implementation
This was reported by coccinelle.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
RH Bugzilla: 1702264
We need to protect so that the call to smb2_reconnect() in
smb2_reconnect_server() does not end up freeing the session
because it can lead to a use after free and crash.
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
The 2nd buffer could be NULL even if iov_len is not zero. This can
trigger a panic when handling symlinks. It's easy to reproduce with
LTP fs_racer scripts[1] which are randomly craete/delete/link files
and dirs. Fix this panic by checking if the 2nd buffer is padding
before kfree, like what we do in SMB2_open_free.
[1] https://github.com/linux-test-project/ltp/tree/master/testcases/kernel/fs/racer
Fixes: 2c87d6a94d ("cifs: Allocate memory for all iovs in smb2_ioctl")
Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie sahlberg <lsahlber@redhat.com>
Currently in the case where SMB2_ioctl returns the -EOPNOTSUPP error
there is a memory leak of pneg_inbuf. Fix this by returning via
the out_free_inbuf exit path that will perform the relevant kfree.
Addresses-Coverity: ("Resource leak")
Fixes: 969ae8e8d4 ("cifs: Accept validate negotiate if server return NT_STATUS_NOT_SUPPORTED")
CC: Stable <stable@vger.kernel.org> # v5.1+
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
An IOCTL uses up to 2 iovs. The 1st iov is the command itself, the 2nd iov is
optional data for that command. The 1st iov is always allocated on the heap
but the 2nd iov may point to a variable on the stack. This will trigger an
error when passing the 2nd iov for RDMA I/O.
Fix this by allocating a buffer for the 2nd iov.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie sahlberg <lsahlber@redhat.com>
New negotiate context (3) allows the server and client to
negotiate which compression algorithms to use. Add support
for this and save it off in the server structure.
Also now displayed in /proc/fs/cifs/DebugData (see below example
to Windows 10) where compression algoirthm "LZ77" was negotiated:
Servers:
Number of credits: 326 Dialect 0x311 COMPRESS_LZ77 signed
1) Name: 192.168.92.17 Uses: 1 Capability: 0x300067 Session Status: 1 TCP status: 1 Instance: 1
See MS-XCA and MS-SMB2 2.2.3.1 for more details.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
The flags were named confusingly.
CIFS_ASYNC_OP now just means that we will not block waiting for credits
to become available so we thus rename this to be CIFS_NON_BLOCKING.
Change CIFS_NO_RESP to CIFS_NO_RSP_BUF to clarify that we will actually get a
response from the server but we will not get/do not want a response buffer.
Delete CIFSSMBNotify. This is an SMB1 function that is not used.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Useful for improved copy performance as well as for
applications which query allocated ranges of sparse
files.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
See the latest MS-SMB2 protocol specification updates.
These will be needed for implementing compression support
on the wire for example.
Signed-off-by: Steve French <stfrench@microsoft.com>
Memory registration failure doesn't mean this I/O has failed, it means the
transport is hitting I/O error or needs reconnect. This error is not from
the server.
Indicate this error to upper layer, and let upper layer decide how to
reconnect and proceed with this I/O.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Commit 088aaf17aa introduced a leak where
if SMB2_read() returned an error we would return without freeing the
request buffer.
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
There is a KASAN slab-out-of-bounds:
BUG: KASAN: slab-out-of-bounds in _copy_from_iter_full+0x783/0xaa0
Read of size 80 at addr ffff88810c35e180 by task mount.cifs/539
CPU: 1 PID: 539 Comm: mount.cifs Not tainted 4.19 #10
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0xdd/0x12a
print_address_description+0xa7/0x540
kasan_report+0x1ff/0x550
check_memory_region+0x2f1/0x310
memcpy+0x2f/0x80
_copy_from_iter_full+0x783/0xaa0
tcp_sendmsg_locked+0x1840/0x4140
tcp_sendmsg+0x37/0x60
inet_sendmsg+0x18c/0x490
sock_sendmsg+0xae/0x130
smb_send_kvec+0x29c/0x520
__smb_send_rqst+0x3ef/0xc60
smb_send_rqst+0x25a/0x2e0
compound_send_recv+0x9e8/0x2af0
cifs_send_recv+0x24/0x30
SMB2_open+0x35e/0x1620
open_shroot+0x27b/0x490
smb2_open_op_close+0x4e1/0x590
smb2_query_path_info+0x2ac/0x650
cifs_get_inode_info+0x1058/0x28f0
cifs_root_iget+0x3bb/0xf80
cifs_smb3_do_mount+0xe00/0x14c0
cifs_do_mount+0x15/0x20
mount_fs+0x5e/0x290
vfs_kern_mount+0x88/0x460
do_mount+0x398/0x31e0
ksys_mount+0xc6/0x150
__x64_sys_mount+0xea/0x190
do_syscall_64+0x122/0x590
entry_SYSCALL_64_after_hwframe+0x44/0xa9
It can be reproduced by the following step:
1. samba configured with: server max protocol = SMB2_10
2. mount -o vers=default
When parse the mount version parameter, the 'ops' and 'vals'
was setted to smb30, if negotiate result is smb21, just
update the 'ops' to smb21, but the 'vals' is still smb30.
When add lease context, the iov_base is allocated with smb21
ops, but the iov_len is initiallited with the smb30. Because
the iov_len is longer than iov_base, when send the message,
copy array out of bounds.
we need to keep the 'ops' and 'vals' consistent.
Fixes: 9764c02fcb ("SMB3: Add support for multidialect negotiate (SMB2.1 and later)")
Fixes: d5c7076b77 ("smb3: add smb3.1.1 to default dialect list")
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
There is a KASAN use-after-free:
BUG: KASAN: use-after-free in SMB2_read+0x1136/0x1190
Read of size 8 at addr ffff8880b4e45e50 by task ln/1009
Should not release the 'req' because it will use in the trace.
Fixes: eccb4422cf ("smb3: Add ftrace tracepoints for improved SMB3 debugging")
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org> 4.18+
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
There is a KASAN use-after-free:
BUG: KASAN: use-after-free in SMB2_write+0x1342/0x1580
Read of size 8 at addr ffff8880b6a8e450 by task ln/4196
Should not release the 'req' because it will use in the trace.
Fixes: eccb4422cf ("smb3: Add ftrace tracepoints for improved SMB3 debugging")
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org> 4.18+
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reconnecting after server or network failure can be improved
(to maintain availability and protect data integrity) by allowing
the client to choose the default persistent (or resilient)
handle timeout in some use cases. Today we default to 0 which lets
the server pick the default timeout (usually 120 seconds) but this
can be problematic for some workloads. Add the new mount parameter
to cifs.ko for SMB3 mounts "handletimeout" which enables the user
to override the default handle timeout for persistent (mount
option "persistenthandles") or resilient handles (mount option
"resilienthandles"). Maximum allowed is 16 minutes (960000 ms).
Units for the timeout are expressed in milliseconds. See
section 2.2.14.2.12 and 2.2.31.3 of the MS-SMB2 protocol
specification for more information.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
Some servers (see MS-SMB2 protocol specification
section 3.3.5.15.1) expect that the FSCTL enumerate snapshots
is done twice, with the first query having EXACTLY the minimum
size response buffer requested (16 bytes) which refreshes
the snapshot list (otherwise that and subsequent queries get
an empty list returned). So had to add code to set
the maximum response size differently for the first snapshot
query (which gets the size needed for the second query which
contains the actual list of snapshots).
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org> # 4.19+
Workaround problem with Samba responses to SMB3.1.1
null user (guest) mounts. The server doesn't set the
expected flag in the session setup response so we have
to do a similar check to what is done in smb3_validate_negotiate
where we also check if the user is a null user (but not sec=krb5
since username might not be passed in on mount for Kerberos case).
Note that the commit below tightened the conditions and forced signing
for the SMB2-TreeConnect commands as per MS-SMB2.
However, this should only apply to normal user sessions and not for
cases where there is no user (even if server forgets to set the flag
in the response) since we don't have anything useful to sign with.
This is especially important now that the more secure SMB3.1.1 protocol
is in the default dialect list.
An earlier patch ("cifs: allow guest mounts to work for smb3.11") fixed
the guest mounts to Windows.
Fixes: 6188f28bf6 ("Tree connect for SMB3.1.1 must be signed for non-encrypted shares")
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>