Commit Graph

48 Commits

Author SHA1 Message Date
Steve French 35f834265e smb3: fix broken reconnect when password changing on the server by allowing password rotation
There are various use cases that are becoming more common in which password
changes are scheduled on a server(s) periodically but the clients connected
to this server need to stay connected (even in the face of brief network
reconnects) due to mounts which can not be easily unmounted and mounted at
will, and servers that do password rotation do not always have the ability
to tell the clients exactly when to the new password will be effective,
so add support for an alt password ("password2=") on mount (and also
remount) so that we can anticipate the upcoming change to the server
without risking breaking existing mounts.

An alternative would have been to use the kernel keyring for this but the
processes doing the reconnect do not have access to the keyring but do
have access to the ses structure.

Reviewed-by: Bharath SM <bharathsm@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-04-11 16:03:48 -05:00
Paulo Alcantara e0e50401cc smb: client: fix potential UAF in cifs_signal_cifsd_for_reconnect()
Skip sessions that are being teared down (status == SES_EXITING) to
avoid UAF.

Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-04-03 14:45:15 -05:00
Paulo Alcantara 93cee45ccf smb: client: serialise cifs_construct_tcon() with cifs_mount_mutex
Serialise cifs_construct_tcon() with cifs_mount_mutex to handle
parallel mounts that may end up reusing the session and tcon created
by it.

Cc: stable@vger.kernel.org # 6.4+
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-04-02 10:12:22 -05:00
Paulo Alcantara 4a5ba0e0bf smb: client: handle DFS tcons in cifs_construct_tcon()
The tcons created by cifs_construct_tcon() on multiuser mounts must
also be able to failover and refresh DFS referrals, so set the
appropriate fields in order to get a full DFS tcon.  They could be
shared among different superblocks later, too.

Cc: stable@vger.kernel.org # 6.4+
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202404021518.3Xu2VU4s-lkp@intel.com/
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-04-02 10:12:13 -05:00
Paulo Alcantara 062a7f0ff4 smb: client: guarantee refcounted children from parent session
Avoid potential use-after-free bugs when walking DFS referrals,
mounting and performing DFS failover by ensuring that all children
from parent @tcon->ses are also refcounted.  They're all needed across
the entire DFS mount.  Get rid of @tcon->dfs_ses_list while we're at
it, too.

Cc: stable@vger.kernel.org # 6.4+
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202404021527.ZlRkIxgv-lkp@intel.com/
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-04-02 10:09:57 -05:00
Paulo Alcantara 24a9799aa8 smb: client: fix UAF in smb2_reconnect_server()
The UAF bug is due to smb2_reconnect_server() accessing a session that
is already being teared down by another thread that is executing
__cifs_put_smb_ses().  This can happen when (a) the client has
connection to the server but no session or (b) another thread ends up
setting @ses->ses_status again to something different than
SES_EXITING.

To fix this, we need to make sure to unconditionally set
@ses->ses_status to SES_EXITING and prevent any other threads from
setting a new status while we're still tearing it down.

The following can be reproduced by adding some delay to right after
the ipc is freed in __cifs_put_smb_ses() - which will give
smb2_reconnect_server() worker a chance to run and then accessing
@ses->ipc:

kinit ...
mount.cifs //srv/share /mnt/1 -o sec=krb5,nohandlecache,echo_interval=10
[disconnect srv]
ls /mnt/1 &>/dev/null
sleep 30
kdestroy
[reconnect srv]
sleep 10
umount /mnt/1
...
CIFS: VFS: Verify user has a krb5 ticket and keyutils is installed
CIFS: VFS: \\srv Send error in SessSetup = -126
CIFS: VFS: Verify user has a krb5 ticket and keyutils is installed
CIFS: VFS: \\srv Send error in SessSetup = -126
general protection fault, probably for non-canonical address
0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP NOPTI
CPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc2 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39
04/01/2014
Workqueue: cifsiod smb2_reconnect_server [cifs]
RIP: 0010:__list_del_entry_valid_or_report+0x33/0xf0
Code: 4f 08 48 85 d2 74 42 48 85 c9 74 59 48 b8 00 01 00 00 00 00 ad
de 48 39 c2 74 61 48 b8 22 01 00 00 00 00 74 69 <48> 8b 01 48 39 f8 75
7b 48 8b 72 08 48 39 c6 0f 85 88 00 00 00 b8
RSP: 0018:ffffc900001bfd70 EFLAGS: 00010a83
RAX: dead000000000122 RBX: ffff88810da53838 RCX: 6b6b6b6b6b6b6b6b
RDX: 6b6b6b6b6b6b6b6b RSI: ffffffffc02f6878 RDI: ffff88810da53800
RBP: ffff88810da53800 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88810c064000
R13: 0000000000000001 R14: ffff88810c064000 R15: ffff8881039cc000
FS: 0000000000000000(0000) GS:ffff888157c00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe3728b1000 CR3: 000000010caa4000 CR4: 0000000000750ef0
PKRU: 55555554
Call Trace:
 <TASK>
 ? die_addr+0x36/0x90
 ? exc_general_protection+0x1c1/0x3f0
 ? asm_exc_general_protection+0x26/0x30
 ? __list_del_entry_valid_or_report+0x33/0xf0
 __cifs_put_smb_ses+0x1ae/0x500 [cifs]
 smb2_reconnect_server+0x4ed/0x710 [cifs]
 process_one_work+0x205/0x6b0
 worker_thread+0x191/0x360
 ? __pfx_worker_thread+0x10/0x10
 kthread+0xe2/0x110
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x34/0x50
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-04-01 13:39:20 -05:00
David Howells 5b142b37c7 cifs: Move some extern decls from .c files to .h
Move the following:

        extern mempool_t *cifs_sm_req_poolp;
        extern mempool_t *cifs_req_poolp;
        extern mempool_t *cifs_mid_poolp;
        extern bool disable_legacy_dialects;

from various .c files to cifsglob.h.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-03-20 11:49:24 -05:00
Shyam Prasad N 13c0a74747 cifs: make sure server interfaces are requested only for SMB3+
Some code paths for querying server interfaces make a false
assumption that it will only get called for SMB3+. Since this
function now can get called from a generic code paths, the correct
thing to do is to have specific handler for this functionality
per SMB dialect, and call this handler.

This change adds such a handler and implements this handler only
for SMB 3.0 and 3.1.1.

Cc: stable@vger.kernel.org
Cc: Jan Čermák <sairon@sairon.cz>
Reported-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-03-14 13:54:27 -05:00
Enzo Matsumiya 8fe7062b7d smb: client: negotiate compression algorithms
Change "compress=" mount option to a boolean flag, that, if set,
will enable negotiating compression algorithms with the server.

Do not de/compress anything for now.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-03-10 19:52:42 -05:00
Paulo Alcantara eb90e8ecb2 smb: client: introduce reparse mount option
Allow the user to create special files and symlinks by choosing
between WSL and NFS reparse points via 'reparse={nfs,wsl}' mount
options.  If unset or 'reparse=default', the client will default to
creating them via NFS reparse points.

Creating WSL reparse points isn't supported yet, so simply return
error when attempting to mount with 'reparse=wsl' for now.

Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-03-10 19:33:54 -05:00
Steve French 4860abb91f smb: Fix regression in writes when non-standard maximum write size negotiated
The conversion to netfs in the 6.3 kernel caused a regression when
maximum write size is set by the server to an unexpected value which is
not a multiple of 4096 (similarly if the user overrides the maximum
write size by setting mount parm "wsize", but sets it to a value that
is not a multiple of 4096).  When negotiated write size is not a
multiple of 4096 the netfs code can skip the end of the final
page when doing large sequential writes, causing data corruption.

This section of code is being rewritten/removed due to a large
netfs change, but until that point (ie for the 6.3 kernel until now)
we can not support non-standard maximum write sizes.

Add a warning if a user specifies a wsize on mount that is not
a multiple of 4096 (and round down), also add a change where we
round down the maximum write size if the server negotiates a value
that is not a multiple of 4096 (we also have to check to make sure that
we do not round it down to zero).

Reported-by: R. Diez" <rdiez-2006@rd10.de>
Fixes: d08089f649 ("cifs: Change the I/O paths to use an iterator rather than a page list")
Suggested-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Acked-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Tested-by: Matthew Ruffell <matthew.ruffell@canonical.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Cc: stable@vger.kernel.org # v6.3+
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-02-15 22:19:23 -06:00
Shyam Prasad N a39c757bf0 cifs: handle cases where multiple sessions share connection
Based on our implementation of multichannel, it is entirely
possible that a server struct may not be found in any channel
of an SMB session.

In such cases, we should be prepared to move on and search for
the server struct in the next session.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-02-09 14:43:25 -06:00
Shyam Prasad N c6e02eefd6 cifs: change tcon status when need_reconnect is set on it
When a tcon is marked for need_reconnect, the intention
is to have it reconnected.

This change adjusts tcon->status in cifs_tree_connect
when need_reconnect is set. Also, this change has a minor
correction in resetting need_reconnect on success. It makes
sure that it is done with tc_lock held.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-02-09 14:43:23 -06:00
Shyam Prasad N ce09f8d8a7 cifs: new mount option called retrans
We have several places in the code where we treat the
error -EAGAIN very differently. Some code retry for
arbitrary number of times.

Introducing this new mount option named "retrans", so
that all these handlers of -EAGAIN can retry a fixed
number of times. This applies only to soft mounts.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-01-19 10:31:57 -06:00
Pierre Mariani 0108ce08ae smb: client: Fix minor whitespace errors and warnings
Fixes no-op checkpatch errors and warnings.

Signed-off-by: Pierre Mariani <pierre.mariani@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-01-07 15:46:05 -06:00
Shyam Prasad N 7257bcf3bd cifs: cifs_chan_is_iface_active should be called with chan_lock held
cifs_chan_is_iface_active checks the channels of a session to see
if the associated iface is active. This should always happen
with chan_lock held. However, these two callers of this function
were missing this locking.

This change makes sure the function calls are protected with
proper locking.

Fixes: b54034a73b ("cifs: during reconnect, update interface if necessary")
Fixes: fa1d0508bd ("cifs: account for primary channel in the interface list")
Cc: stable@vger.kernel.org
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-12-29 09:08:59 -06:00
Shyam Prasad N 27e1fd343f cifs: after disabling multichannel, mark tcon for reconnect
Once the server disables multichannel for an active multichannel
session, on the following reconnect, the client would reduce
the number of channels to 1. However, it could be the case that
the tree connect was active on one of these disabled channels.
This results in an unrecoverable state.

This change fixes that by making sure that whenever a channel
is being terminated, the session and tcon are marked for
reconnect too. This could mean a few redundant tree connect
calls to the server, but considering that this is not a frequent
event, we should be okay.

Fixes: ee1d21794e ("cifs: handle when server stops supporting multichannel")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-12-29 09:03:08 -06:00
Paulo Alcantara a8f68b1115 smb: client: fix OOB in cifsd when receiving compounded resps
Validate next header's offset in ->next_header() so that it isn't
smaller than MID_HEADER_SIZE(server) and then standard_receive3() or
->receive() ends up writing off the end of the buffer because
'pdu_length - MID_HEADER_SIZE(server)' wraps up to a huge length:

  BUG: KASAN: slab-out-of-bounds in _copy_to_iter+0x4fc/0x840
  Write of size 701 at addr ffff88800caf407f by task cifsd/1090

  CPU: 0 PID: 1090 Comm: cifsd Not tainted 6.7.0-rc4 #5
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
  rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
  Call Trace:
   <TASK>
   dump_stack_lvl+0x4a/0x80
   print_report+0xcf/0x650
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __phys_addr+0x46/0x90
   kasan_report+0xd8/0x110
   ? _copy_to_iter+0x4fc/0x840
   ? _copy_to_iter+0x4fc/0x840
   kasan_check_range+0x105/0x1b0
   __asan_memcpy+0x3c/0x60
   _copy_to_iter+0x4fc/0x840
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? hlock_class+0x32/0xc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __pfx__copy_to_iter+0x10/0x10
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? lock_is_held_type+0x90/0x100
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __might_resched+0x278/0x360
   ? __pfx___might_resched+0x10/0x10
   ? srso_alias_return_thunk+0x5/0xfbef5
   __skb_datagram_iter+0x2c2/0x460
   ? __pfx_simple_copy_to_iter+0x10/0x10
   skb_copy_datagram_iter+0x6c/0x110
   tcp_recvmsg_locked+0x9be/0xf40
   ? __pfx_tcp_recvmsg_locked+0x10/0x10
   ? mark_held_locks+0x5d/0x90
   ? srso_alias_return_thunk+0x5/0xfbef5
   tcp_recvmsg+0xe2/0x310
   ? __pfx_tcp_recvmsg+0x10/0x10
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? lock_acquire+0x14a/0x3a0
   ? srso_alias_return_thunk+0x5/0xfbef5
   inet_recvmsg+0xd0/0x370
   ? __pfx_inet_recvmsg+0x10/0x10
   ? __pfx_lock_release+0x10/0x10
   ? do_raw_spin_trylock+0xd1/0x120
   sock_recvmsg+0x10d/0x150
   cifs_readv_from_socket+0x25a/0x490 [cifs]
   ? __pfx_cifs_readv_from_socket+0x10/0x10 [cifs]
   ? srso_alias_return_thunk+0x5/0xfbef5
   cifs_read_from_socket+0xb5/0x100 [cifs]
   ? __pfx_cifs_read_from_socket+0x10/0x10 [cifs]
   ? __pfx_lock_release+0x10/0x10
   ? do_raw_spin_trylock+0xd1/0x120
   ? _raw_spin_unlock+0x23/0x40
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __smb2_find_mid+0x126/0x230 [cifs]
   cifs_demultiplex_thread+0xd39/0x1270 [cifs]
   ? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs]
   ? __pfx_lock_release+0x10/0x10
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? mark_held_locks+0x1a/0x90
   ? lockdep_hardirqs_on_prepare+0x136/0x210
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __kthread_parkme+0xce/0xf0
   ? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs]
   kthread+0x18d/0x1d0
   ? kthread+0xdb/0x1d0
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0x34/0x60
   ? __pfx_kthread+0x10/0x10
   ret_from_fork_asm+0x1b/0x30
   </TASK>

Fixes: 8ce79ec359 ("cifs: update multiplex loop to handle compounded responses")
Cc: stable@vger.kernel.org
Reported-by: Robert Morris <rtm@csail.mit.edu>
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-12-17 19:00:12 -06:00
Shyam Prasad N 04909192ad cifs: reconnect worker should take reference on server struct unconditionally
Reconnect worker currently assumes that the server struct
is alive and only takes reference on the server if it needs
to call smb2_reconnect.

With the new ability to disable channels based on whether the
server has multichannel disabled, this becomes a problem when
we need to disable established channels. While disabling the
channels and deallocating the server, there could be reconnect
work that could not be cancelled (because it started).

This change forces the reconnect worker to unconditionally
take a reference on the server when it runs.

Also, this change now allows smb2_reconnect to know if it was
called by the reconnect worker. Based on this, the cifs_put_tcp_session
can decide whether it can cancel the reconnect work synchronously or not.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-12-06 11:04:23 -06:00
Shyam Prasad N 8233425248 Revert "cifs: reconnect work should have reference on server struct"
This reverts commit 19a4b9d6c3.

This earlier commit was making an assumption that each mod_delayed_work
called for the reconnect work would result in smb2_reconnect_server
being called twice. This assumption turns out to be untrue. So reverting
this change for now.

I will submit a follow-up patch to fix the actual problem in a different
way.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-12-06 11:03:36 -06:00
Shyam Prasad N 29954d5b1e cifs: fix leak of iface for primary channel
My last change in this area introduced a change which
accounted for primary channel in the interface ref count.
However, it did not reduce this ref count on deallocation
of the primary channel. i.e. during umount.

Fixing this leak here, by dropping this ref count for
primary channel while freeing up the session.

Fixes: fa1d0508bd ("cifs: account for primary channel in the interface list")
Cc: stable@vger.kernel.org
Reported-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-14 11:38:00 -06:00
Shyam Prasad N ee1d21794e cifs: handle when server stops supporting multichannel
When a server stops supporting multichannel, we will
keep attempting reconnects to the secondary channels today.
Avoid this by freeing extra channels when negotiate
returns no multichannel support.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-10 09:33:19 -06:00
Shyam Prasad N 705fc522fe cifs: handle when server starts supporting multichannel
When the user mounts with multichannel option, but the
server does not support it, there can be a time in future
where it can be supported.

With this change, such a case is handled.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
2023-11-10 09:33:15 -06:00
Shyam Prasad N 19a4b9d6c3 cifs: reconnect work should have reference on server struct
The delayed work for reconnect takes server struct
as a parameter. But it does so without holding a ref
to it. Normally, this may not show a problem as
the reconnect work is only cancelled on umount.

However, since we now plan to support scaling down of
channels, and the scale down can happen from reconnect
work itself, we need to fix it.

This change takes a reference on the server struct
before it is passed to the delayed work. And drops
the reference in the delayed work itself. Or if
the delayed work is successfully cancelled, by the
process that cancels it.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-09 10:25:32 -06:00
Shyam Prasad N 9599d59eb8 cifs: do not pass cifs_sb when trying to add channels
The only reason why cifs_sb gets passed today to cifs_try_adding_channels
is to pass the local_nls field for the new channels and binding session.
However, the ses struct already has local_nls field that is setup during
the first cifs_setup_session. So there is no need to pass cifs_sb.

This change removes cifs_sb from the arg list for this and the functions
that it calls and uses ses->local_nls instead.

Cc: stable@vger.kernel.org
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-09 10:25:21 -06:00
Shyam Prasad N 0c51cc6f2c cifs: handle cases where a channel is closed
So far, SMB multichannel could only scale up, but not
scale down the number of channels. In this series of
patch, we now allow the client to deal with the case
of multichannel disabled on the server when the share
is mounted. With that change, we now need the ability
to scale down the channels.

This change allows the client to deal with cases of
missing channels more gracefully.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-09 10:25:14 -06:00
Shyam Prasad N d9a6d78096 cifs: force interface update before a fresh session setup
During a session reconnect, it is possible that the
server moved to another physical server (happens in case
of Azure files). So at this time, force a query of server
interfaces again (in case of multichannel session), such
that the secondary channels connect to the right
IP addresses (possibly updated now).

Cc: stable@vger.kernel.org
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-02 08:06:06 -05:00
Shyam Prasad N c3326a61cd cifs: reconnect helper should set reconnect for the right channel
We introduced a helper function to be used by non-cifsd threads to
mark the connection for reconnect. For multichannel, when only
a particular channel needs to be reconnected, this had a bug.

This change fixes that by marking that particular channel
for reconnect.

Fixes: dca65818c8 ("cifs: use a different reconnect helper for non-cifsd threads")
Cc: stable@vger.kernel.org
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-02 08:06:06 -05:00
Paulo Alcantara c37ed2d7d0 smb: client: remove extra @chan_count check in __cifs_put_smb_ses()
If @ses->chan_count <= 1, then for-loop body will not be executed so
no need to check it twice.

Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-02 08:05:45 -05:00
Shyam Prasad N 4cf6e1101a cifs: add xid to query server interface call
We were passing 0 as the xid for the call to query
server interfaces. This is not great for debugging.
This change adds a real xid.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Bharath SM <bharathsm@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-10-31 12:38:26 -05:00
Paulo Alcantara 3b8bb31715 smb: client: do not start laundromat thread on nohandlecache
Honor 'nohandlecache' mount option by not starting laundromat thread
even when SMB server supports directory leases. Do not waste system
resources by having laundromat thread running with no directory
caching at all.

Fixes: 2da338ff75 ("smb3: do not start laundromat thread when dir leases  disabled")
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-10-04 16:21:15 -05:00
Jordan Rife cedc019b9f smb: use kernel_connect() and kernel_bind()
Recent changes to kernel_connect() and kernel_bind() ensure that
callers are insulated from changes to the address parameter made by BPF
SOCK_ADDR hooks. This patch wraps direct calls to ops->connect() and
ops->bind() with kernel_connect() and kernel_bind() to ensure that SMB
mounts do not see their mount address overwritten in such cases.

Link: https://lore.kernel.org/netdev/9944248dba1bce861375fcce9de663934d933ba9.camel@redhat.com/
Cc: <stable@vger.kernel.org> # 6.0+
Signed-off-by: Jordan Rife <jrife@google.com>
Acked-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-10-04 16:18:27 -05:00
Steve French 2da338ff75 smb3: do not start laundromat thread when dir leases
disabled

When no directory lease support, or for IPC shares where directories
can not be opened, do not start an unneeded laundromat thread for
that mount (it wastes resources).

Fixes: d14de8067e ("cifs: Add a laundromat thread for cached directories")
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Acked-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-09-19 13:32:02 -05:00
Steve French 6a50d71d0f smb3: allow controlling maximum number of cached directories
Allow adjusting the maximum number of cached directories per share
(defaults to 16) via mount parm "max_cached_dirs"

Signed-off-by: Steve French <stfrench@microsoft.com>
2023-09-07 00:06:04 -05:00
Steve French b3773b19d4 SMB3: rename macro CIFS_SERVER_IS_CHAN to avoid confusion
Since older dialects such as CIFS do not support multichannel
the macro CIFS_SERVER_IS_CHAN can be confusing (it requires SMB 3
or later) so shorten its name to "SERVER_IS_CHAN"

Suggested-by: Tom Talpey <tom@talpey.com>
Acked-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-08-30 08:55:02 -05:00
Steve French 09ee7a3bf8 [SMB3] send channel sequence number in SMB3 requests after reconnects
The ChannelSequence field in the SMB3 header is supposed to be
increased after reconnect to allow the server to distinguish
requests from before and after the reconnect.  We had always
been setting it to zero.  There are cases where incrementing
ChannelSequence on requests after network reconnects can reduce
the chance of data corruptions.

See MS-SMB2 3.2.4.1 and 3.2.7.1

Signed-off-by: Steve French <stfrench@microsoft.com>
Cc: stable@vger.kernel.org # 5.16+
2023-08-24 23:37:06 -05:00
Paulo Alcantara 946ad1b8b1 smb: client: reduce stack usage in cifs_demultiplex_thread()
Clang warns about exceeded stack frame size

  fs/smb/client/connect.c:1109:1: warning: stack frame size (1048)
  exceeds limit (1024) in 'cifs_demultiplex_thread'
  [-Wframe-larger-than]

It turns out that clean_demultiplex_info() got inlined into
cifs_demultiplex_thread(), so mark it as noinline_for_stack to save
some stack space.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-08-20 16:05:50 -05:00
Paulo Alcantara 3fea12f3c6 smb: client: introduce DFS_CACHE_TGT_LIST()
Add new helper which declares and initialises target list of a DFS
referral rather having to do both separately.

No functional changes.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-08-20 16:05:49 -05:00
Winston Wen a43f95fdd3 cifs: fix charset issue in reconnection
We need to specify charset, like "iocharset=utf-8", in mount options for
Chinese path if the nls_default don't support it, such as iso8859-1, the
default value for CONFIG_NLS_DEFAULT.

But now in reconnection the nls_default is used, instead of the one we
specified and used in mount, and this can lead to mount failure.

Signed-off-by: Winston Wen <wentao@uniontech.com>
Reviewed-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-07-25 00:31:24 -05:00
Shyam Prasad N 69cba9d3c1 cifs: fix mid leak during reconnection after timeout threshold
When the number of responses with status of STATUS_IO_TIMEOUT
exceeds a specified threshold (NUM_STATUS_IO_TIMEOUT), we reconnect
the connection. But we do not return the mid, or the credits
returned for the mid, or reduce the number of in-flight requests.

This bug could result in the server->in_flight count to go bad,
and also cause a leak in the mids.

This change moves the check to a few lines below where the
response is decrypted, even of the response is read from the
transform header. This way, the code for returning the mids
can be reused.

Also, the cifs_reconnect was reconnecting just the transport
connection before. In case of multi-channel, this may not be
what we want to do after several timeouts. Changed that to
reconnect the session and the tree too.

Also renamed NUM_STATUS_IO_TIMEOUT to a more appropriate name
MAX_STATUS_IO_TIMEOUT.

Fixes: 8e670f77c4 ("Handle STATUS_IO_TIMEOUT gracefully")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-07-14 11:25:08 -05:00
Shyam Prasad N c071b34f62 cifs: is_network_name_deleted should return a bool
Currently, is_network_name_deleted and it's implementations
do not return anything if the network name did get deleted.
So the function doesn't fully achieve what it advertizes.

Changed the function to return a bool instead. It will now
return true if the error returned is STATUS_NETWORK_NAME_DELETED
and the share (tree id) was found to be connected. It returns
false otherwise.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Acked-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-07-14 11:24:14 -05:00
Winston Wen ff7d80a9f2 cifs: fix session state transition to avoid use-after-free issue
We switch session state to SES_EXITING without cifs_tcp_ses_lock now,
it may lead to potential use-after-free issue.

Consider the following execution processes:

Thread 1:
__cifs_put_smb_ses()
    spin_lock(&cifs_tcp_ses_lock)
    if (--ses->ses_count > 0)
        spin_unlock(&cifs_tcp_ses_lock)
        return
    spin_unlock(&cifs_tcp_ses_lock)
        ---> **GAP**
    spin_lock(&ses->ses_lock)
    if (ses->ses_status == SES_GOOD)
        ses->ses_status = SES_EXITING
    spin_unlock(&ses->ses_lock)

Thread 2:
cifs_find_smb_ses()
    spin_lock(&cifs_tcp_ses_lock)
    list_for_each_entry(ses, ...)
        spin_lock(&ses->ses_lock)
        if (ses->ses_status == SES_EXITING)
            spin_unlock(&ses->ses_lock)
            continue
        ...
        spin_unlock(&ses->ses_lock)
    if (ret)
        cifs_smb_ses_inc_refcount(ret)
    spin_unlock(&cifs_tcp_ses_lock)

If thread 1 is preempted in the gap and thread 2 start executing, thread 2
will get the session, and soon thread 1 will switch the session state to
SES_EXITING and start releasing it, even though thread 1 had increased the
session's refcount and still uses it.

So switch session state under cifs_tcp_ses_lock to eliminate this gap.

Signed-off-by: Winston Wen <wentao@uniontech.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-07-01 00:08:59 -05:00
Paulo Alcantara 3ae872de41 smb: client: fix shared DFS root mounts with different prefixes
When having two DFS root mounts that are connected to same namespace,
same mount options but different prefix paths, we can't really use the
shared @server->origin_fullpath when chasing DFS links in them.

Move the origin_fullpath field to cifs_tcon structure so when having
shared DFS root mounts with different prefix paths, and we need to
chase any DFS links, dfs_get_automount_devname() will pick up the
correct full path out of the @tcon that will be used for the new
mount.

Before patch

  mount.cifs //dom/dfs/dir /mnt/1 -o ...
  mount.cifs //dom/dfs /mnt/2 -o ...
  # shared server, ses, tcon
  # server: origin_fullpath=//dom/dfs/dir

  # @server->origin_fullpath + '/dir/link1'
  $ ls /mnt/2/dir/link1
  ls: cannot open directory '/mnt/2/dir/link1': No such file or directory

After patch

  mount.cifs //dom/dfs/dir /mnt/1 -o ...
  mount.cifs //dom/dfs /mnt/2 -o ...
  # shared server & ses
  # tcon_1: origin_fullpath=//dom/dfs/dir
  # tcon_2: origin_fullpath=//dom/dfs

  # @tcon_2->origin_fullpath + '/dir/link1'
  $ ls /mnt/2/dir/link1
  dir0  dir1  dir10  dir3  dir5  dir6  dir7  dir9  target2_file.txt  tsub

Fixes: 8e3554150d ("cifs: fix sharing of DFS connections")
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-06-28 15:48:43 -05:00
Paulo Alcantara f0b6a834a8 smb: client: fix warning in generic_ip_connect()
This fixes the following warning reported by kernel test robot

  fs/smb/client/connect.c:2974 generic_ip_connect() error: we
  previously assumed 'socket' could be null (see line 2962)

Link: https://lore.kernel.org/all/202306170124.CtQqzf0I-lkp@intel.com/
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-06-20 23:03:03 -05:00
Paulo Alcantara fc1bd51d11 smb: client: fix warning in cifs_match_super()
Fix potential dereference of ERR_PTR @tlink as reported by kernel test
robot

  fs/smb/client/connect.c:2775 cifs_match_super() error: 'tlink'
  dereferencing possible ERR_PTR()

Link: https://lore.kernel.org/all/202306170124.CtQqzf0I-lkp@intel.com/
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-06-19 18:16:26 -05:00
Shyam Prasad N 2991b77409 cifs: fix sockaddr comparison in iface_cmp
iface_cmp used to simply do a memcmp of the two
provided struct sockaddrs. The comparison needs to do more
based on the address family. Similar logic was already
present in cifs_match_ipaddr. Doing something similar now.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-06-11 20:52:49 -05:00
Shyam Prasad N 91f4480c41 cifs: fix status checks in cifs_tree_connect
The ordering of status checks at the beginning of
cifs_tree_connect is wrong. As a result, a tcon
which is good may stay marked as needing reconnect
infinitely.

Fixes: 2f0e4f0342 ("cifs: check only tcon status on tcon related functions")
Cc: stable@vger.kernel.org # 6.3
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-06-11 20:52:48 -05:00
Steve French 38c8a9a520 smb: move client and server files to common directory fs/smb
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>
2023-05-24 16:29:21 -05:00