We can detect server unresponsiveness only if echoes are enabled.
Echoes can be disabled under two scenarios:
1. The connection is low on credits, so we've disabled echoes/oplocks.
2. The connection has not seen any request till now (other than
negotiate/sess-setup), which is when we enable these two, based on
the credits available.

So this fix will check for dead connection, only when echo is enabled.
Signed-off-by: NShyam Prasad N <sprasad@microsoft.com>
CC: <stable@vger.kernel.org> # v5.8+
Signed-off-by: NSteve French <stfrench@microsoft.com>

When mounted multiuser it is hard to dump keys for the other sessions
which makes it hard to debug using network traces (e.g. using wireshark).
Suggested-by: NShyam Prasad N <sprasad@microsoft.com>
Reviewed-by: NShyam Prasad N <sprasad@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Previously we were only able to dump CCM or GCM-128 keys (see "smbinfo keys" e.g.)
to allow network debugging (e.g. wireshark) of mounts to SMB3.1.1 encrypted
shares.  But with the addition of GCM-256 support, we have to be able to dump
32 byte instead of 16 byte keys which requires adding an additional ioctl
for that.
Reviewed-by: NShyam Prasad N <sprasad@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Various filesystem support the shutdown ioctl which is used by various
xfstests. The shutdown ioctl sets a flag on the superblock which
prevents open, unlink, symlink, hardlink, rmdir, create etc.
on the file system until unmount and remounted. The two flags supported
in this patch are:

  FSOP_GOING_FLAGS_LOGFLUSH and FSOP_GOING_FLAGS_NOLOGFLUSH

which require very little other than blocking new operations (since
we do not cache writes to metadata on the client with cifs.ko).
FSOP_GOING_FLAGS_DEFAULT is not supported yet, but could be added in
the future but would need to call syncfs or equivalent to write out
pending data on the mount.

With this patch various xfstests now work including tests 043 through
046 for example.
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>

When file is closed, SMB2 close request is not sent to server
immediately and is deferred for acregmax defined interval. When file is
reopened by same process for read or write, the file handle
is reused if an oplock is held.

When client receives a oplock/lease break, file is closed immediately
if reference count is zero, else oplock is downgraded.
Signed-off-by: NRohith Surabattula <rohiths@microsoft.com>
Reviewed-by: NShyam Prasad N <sprasad@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Now that stronger encryption (gcm256) has been more broadly
tested, and confirmed to work with multiple servers (Windows
and Azure for example), enable it by default.  Although gcm256 is
the second choice we offer (after gcm128 which should be faster),
this change allows mounts to server which are configured to
require the strongest encryption to work (without changing a module
load parameter).
Signed-off-by: NSteve French <stfrench@microsoft.com>
Suggested-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

To 2.32
Signed-off-by: NSteve French <stfrench@microsoft.com>

In some cases readahead of more than the read size can help
(to allow parallel i/o of read ahead which can improve performance).

Ceph introduced a mount parameter "rasize" to allow controlling this.
Add mount parameter "rasize" to allow control of amount of readahead
requested of the server. If rasize not set, rasize defaults to
negotiated rsize as before.
Reviewed-by: NShyam Prasad N <sprasad@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

For servers which don't support copy_range (SMB3 CopyChunk), the
logging of:
 CIFS: VFS: \\server\share refcpy ioctl error -95 getting resume key
can fill the client logs and make debugging real problems more
difficult.  Change the -EOPNOTSUPP on copy_range to a "warn once"
Signed-off-by: NSteve French <stfrench@microsoft.com>

cifs_smb3_do_mount() calls smb3_fs_context_dup() and then
cifs_setup_volume_info(). The latter's subsequent smb3_parse_devname()
call overwrites the cifs_sb->ctx->UNC string already dup'ed by
smb3_fs_context_dup(), resulting in a leak. E.g.

unreferenced object 0xffff888002980420 (size 32):
  comm "mount", pid 160, jiffies 4294892541 (age 30.416s)
  hex dump (first 32 bytes):
    5c 5c 31 39 32 2e 31 36 38 2e 31 37 34 2e 31 30  \\192.168.174.10
    34 5c 72 61 70 69 64 6f 2d 73 68 61 72 65 00 00  4\rapido-share..
  backtrace:
    [<00000000069e12f6>] kstrdup+0x28/0x50
    [<00000000b61f4032>] smb3_fs_context_dup+0x127/0x1d0 [cifs]
    [<00000000c6e3e3bf>] cifs_smb3_do_mount+0x77/0x660 [cifs]
    [<0000000063467a6b>] smb3_get_tree+0xdf/0x220 [cifs]
    [<00000000716f731e>] vfs_get_tree+0x1b/0x90
    [<00000000491d3892>] path_mount+0x62a/0x910
    [<0000000046b2e774>] do_mount+0x50/0x70
    [<00000000ca7b64dd>] __x64_sys_mount+0x81/0xd0
    [<00000000b5122496>] do_syscall_64+0x33/0x40
    [<000000002dd397af>] entry_SYSCALL_64_after_hwframe+0x44/0xae

This change is a bandaid until the cifs_setup_volume_info() TODO and
error handling issues are resolved.
Signed-off-by: NDavid Disseldorp <ddiss@suse.de>
Acked-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
CC: <stable@vger.kernel.org> # v5.11+
Signed-off-by: NSteve French <stfrench@microsoft.com>

pfid is being set to tcon->crfid.fid and they are copied in each other
multiple times. Remove the memcopy between same pointers - memory
locations.

Addresses-Coverity: ("Overlapped copy")
Fixes: 9e81e8ff ("cifs: return cached_fid from open_shroot")
Signed-off-by: NMuhammad Usama Anjum <musamaanjum@gmail.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Avoid a warning if the error percolates back up:

[440700.376476] CIFS VFS: \\otters.example.com crypt_message: Could not get encryption key
[440700.386947] ------------[ cut here ]------------
[440700.386948] err = 1
[440700.386977] WARNING: CPU: 11 PID: 2733 at /build/linux-hwe-5.4-p6lk6L/linux-hwe-5.4-5.4.0/lib/errseq.c:74 errseq_set+0x5c/0x70
...
[440700.397304] CPU: 11 PID: 2733 Comm: tar Tainted: G           OE     5.4.0-70-generic #78~18.04.1-Ubuntu
...
[440700.397334] Call Trace:
[440700.397346]  __filemap_set_wb_err+0x1a/0x70
[440700.397419]  cifs_writepages+0x9c7/0xb30 [cifs]
[440700.397426]  do_writepages+0x4b/0xe0
[440700.397444]  __filemap_fdatawrite_range+0xcb/0x100
[440700.397455]  filemap_write_and_wait+0x42/0xa0
[440700.397486]  cifs_setattr+0x68b/0xf30 [cifs]
[440700.397493]  notify_change+0x358/0x4a0
[440700.397500]  utimes_common+0xe9/0x1c0
[440700.397510]  do_utimes+0xc5/0x150
[440700.397520]  __x64_sys_utimensat+0x88/0xd0

Fixes: 61cfac6f ("CIFS: Fix possible use after free in demultiplex thread")
Signed-off-by: NPaul Aurich <paul@darkrain42.org>
CC: stable@vger.kernel.org
Signed-off-by: NSteve French <stfrench@microsoft.com>

If smb3_notify() is called at mount point of CIFS, build_path_from_dentry()
returns the pointer to kmalloc-ed memory with terminating zero (this is
empty FileName to be passed to SMB2 CREATE request). This pointer is assigned
to the `path` variable.
Then `path + 1` (to skip first backslash symbol) is passed to
cifs_convert_path_to_utf16(). This is incorrect for empty path and causes
out-of-bound memory access.

Get rid of this "increase by one". cifs_convert_path_to_utf16() already
contains the check for leading backslash in the path.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=212693
CC: <stable@vger.kernel.org> # v5.6+
Signed-off-by: NEugene Korenevsky <ekorenevsky@astralinux.ru>
Signed-off-by: NSteve French <stfrench@microsoft.com>

* rqst[1,2,3] is allocated in vars
* each rqst->rq_iov is also allocated in vars or using pooled memory

SMB2_open_free, SMB2_ioctl_free, SMB2_query_info_free are iterating on
each rqst after vars has been freed (use-after-free), and they are
freeing the kvec a second time (double-free).

How to trigger:

* compile with KASAN
* mount a share

$ smbinfo quota /mnt/foo
Segmentation fault
$ dmesg

 ==================================================================
 BUG: KASAN: use-after-free in SMB2_open_free+0x1c/0xa0
 Read of size 8 at addr ffff888007b10c00 by task python3/1200

 CPU: 2 PID: 1200 Comm: python3 Not tainted 5.12.0-rc6+ #107
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-0-g155821a-rebuilt.opensuse.org 04/01/2014
 Call Trace:
  dump_stack+0x93/0xc2
  print_address_description.constprop.0+0x18/0x130
  ? SMB2_open_free+0x1c/0xa0
  ? SMB2_open_free+0x1c/0xa0
  kasan_report.cold+0x7f/0x111
  ? smb2_ioctl_query_info+0x240/0x990
  ? SMB2_open_free+0x1c/0xa0
  SMB2_open_free+0x1c/0xa0
  smb2_ioctl_query_info+0x2bf/0x990
  ? smb2_query_reparse_tag+0x600/0x600
  ? cifs_mapchar+0x250/0x250
  ? rcu_read_lock_sched_held+0x3f/0x70
  ? cifs_strndup_to_utf16+0x12c/0x1c0
  ? rwlock_bug.part.0+0x60/0x60
  ? rcu_read_lock_sched_held+0x3f/0x70
  ? cifs_convert_path_to_utf16+0xf8/0x140
  ? smb2_check_message+0x6f0/0x6f0
  cifs_ioctl+0xf18/0x16b0
  ? smb2_query_reparse_tag+0x600/0x600
  ? cifs_readdir+0x1800/0x1800
  ? selinux_bprm_creds_for_exec+0x4d0/0x4d0
  ? do_user_addr_fault+0x30b/0x950
  ? __x64_sys_openat+0xce/0x140
  __x64_sys_ioctl+0xb9/0xf0
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xae
 RIP: 0033:0x7fdcf1f4ba87
 Code: b3 66 90 48 8b 05 11 14 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 13 2c 00 f7 d8 64 89 01 48
 RSP: 002b:00007ffef1ce7748 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
 RAX: ffffffffffffffda RBX: 00000000c018cf07 RCX: 00007fdcf1f4ba87
 RDX: 0000564c467c5590 RSI: 00000000c018cf07 RDI: 0000000000000003
 RBP: 00007ffef1ce7770 R08: 00007ffef1ce7420 R09: 00007fdcf0e0562b
 R10: 0000000000000100 R11: 0000000000000246 R12: 0000000000004018
 R13: 0000000000000001 R14: 0000000000000003 R15: 0000564c467c5590

 Allocated by task 1200:
  kasan_save_stack+0x1b/0x40
  __kasan_kmalloc+0x7a/0x90
  smb2_ioctl_query_info+0x10e/0x990
  cifs_ioctl+0xf18/0x16b0
  __x64_sys_ioctl+0xb9/0xf0
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xae

 Freed by task 1200:
  kasan_save_stack+0x1b/0x40
  kasan_set_track+0x1c/0x30
  kasan_set_free_info+0x20/0x30
  __kasan_slab_free+0xe5/0x110
  slab_free_freelist_hook+0x53/0x130
  kfree+0xcc/0x320
  smb2_ioctl_query_info+0x2ad/0x990
  cifs_ioctl+0xf18/0x16b0
  __x64_sys_ioctl+0xb9/0xf0
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xae

 The buggy address belongs to the object at ffff888007b10c00
  which belongs to the cache kmalloc-512 of size 512
 The buggy address is located 0 bytes inside of
  512-byte region [ffff888007b10c00, ffff888007b10e00)
 The buggy address belongs to the page:
 page:0000000044e14b75 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7b10
 head:0000000044e14b75 order:2 compound_mapcount:0 compound_pincount:0
 flags: 0x100000000010200(slab|head)
 raw: 0100000000010200 ffffea000015f500 0000000400000004 ffff888001042c80
 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
 page dumped because: kasan: bad access detected

 Memory state around the buggy address:
  ffff888007b10b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffff888007b10b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 >ffff888007b10c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                    ^
  ffff888007b10c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff888007b10d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ==================================================================
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
CC: <stable@vger.kernel.org>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Can aid in making mount problems easier to diagnose
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

This makes the errors accessible from userspace via dmesg and
the fs_context fd.
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Add fs_context param to parsing helpers to be able to log into it in
next patch.

Make some helper static as they are not used outside of fs_context.c
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

This new helper will be used in the fs_context mount option parsing
code. It log errors both in:
* the fs_context log queue for userspace to read
* kernel printk buffer (dmesg, old behaviour)
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Emulated via server side copy and setsize for
SMB3 and later. In the future we could compound
this (and/or optionally use DUPLICATE_EXTENTS
if supported by the server).
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Emulated for SMB3 and later via server side copy
and setsize. Eventually this could be compounded.
Reported-by: Nkernel test robot <lkp@intel.com>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Improves directory metadata caching
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Needed for the final patch in the directory caching series
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

and clear the timestamp when we receive a lease break.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Needed for subsequent patches in the directory caching
series.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

We need to hold both a reference for the root/superblock as well as the directory that we
are caching. We need to drop these references before we call kill_anon_sb().

At this point, the root and the cached dentries are always the same but this will change
once we start caching other directories as well.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

And use this to only allow to take out a shared handle once the mount has completed and the
sb becomes available.
This will become important in follow up patches where we will start holding a reference to the
directory dentry for the shared handle during the lifetime of the handle.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

These functions will eventually be used to cache any directory, not just the root
so change the names.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Move the check for the directory path into the open_shroot() function
but still fail for any non-root directories.
This is preparation for later when we will start using the cache also
for other directories than the root.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

instead of doing it in the callsites for open_shroot.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

The cost is that we might need to flip '/' to '\\' in more than
just the prefix.  Needs profiling, but I suspect that we won't
get slowdown on that.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NSteve French <stfrench@microsoft.com>

build_path_from_dentry() open-codes dentry_path_raw().  The reason
we can't use dentry_path_raw() in there (and postprocess the
result as needed) is that the callers of build_path_from_dentry()
expect that the object to be freed on cleanup and the string to
be used are at the same address.  That's painful, since the path
is naturally built end-to-beginning - we start at the leaf and
go through the ancestors, accumulating the pathname.

Life would be easier if we left the buffer allocation to callers.
It wouldn't be exact-sized buffer, but none of the callers keep
the result for long - it's always freed before the caller returns.
So there's no need to do exact-sized allocation; better use
__getname()/__putname(), same as we do for pathname arguments
of syscalls.  What's more, there's no need to do allocation under
spinlocks, so GFP_ATOMIC is not needed.

Next patch will replace the open-coded dentry_path_raw() (in
build_path_from_dentry_optional_prefix()) with calling the real
thing.  This patch only introduces wrappers for allocating/freeing
the buffers and switches to new calling conventions:
	build_path_from_dentry(dentry, buf)
expects buf to be address of a page-sized object or NULL,
return value is a pathname built inside that buffer on success,
ERR_PTR(-ENOMEM) if buf is NULL and ERR_PTR(-ENAMETOOLONG) if
the pathname won't fit into page.  Note that we don't need to
check for failure when allocating the buffer in the caller -
build_path_from_dentry() will do the right thing.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NSteve French <stfrench@microsoft.com>

... and adjust the callers.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NSteve French <stfrench@microsoft.com>

As it is, it takes const char * and, in some cases, stores it in
caller's variable that is plain char *.  Fortunately, none of the
callers actually proceeded to modify the string via now-non-const
alias, but that's trouble waiting to happen.

It's easy to do properly, anyway...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NSteve French <stfrench@microsoft.com>

strndup(s, strlen(s)) is a highly unidiomatic way to spell strdup(s);
it's *NOT* safer in any way, since strlen() is just as sensitive to
NUL-termination as strdup() is.

strndup() is for situations when you need a copy of a known-sized
substring, not a magic security juju to drive the bad spirits away.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Protocol has been extended for additional compression headers.
See MS-SMB2 section 2.2.42
Signed-off-by: NSteve French <stfrench@microsoft.com>

While reviewing a patch clarifying locks and locking hierarchy I
realized some locks were unused.

This commit removes old data and code that isn't actually used
anywhere, or hidden in ifdefs which cannot be enabled from the kernel
config.

* The uid/gid trees and associated locks are left-overs from when
  uid/sid mapping had an extra caching layer on top of the keyring and
  are now unused.
  See commit faa65f07 ("cifs: simplify id_to_sid and sid_to_id mapping code")
  from 2012.

* cifs_oplock_break_ops is a left-over from when slow_work was remplaced
  by regular workqueue and is now unused.
  See commit 9b646972 ("cifs: use workqueue instead of slow-work")
  from 2010.

* CIFSSMBSetAttrLegacy is SMB1 cruft dealing with some legacy
  NT4/Win9x behaviour.

* Remove CONFIG_CIFS_DNOTIFY_EXPERIMENTAL left-overs. This was already
  partially removed in 392e1c5d ("cifs: rename and clarify CIFS_ASYNC_OP and CIFS_NO_RESP")
  from 2019. Kill it completely.

* Another candidate that was considered but spared is
  CONFIG_CIFS_NFSD_EXPORT which has an empty implementation and cannot
  be enabled by a config option (although it is listed but disabled with
  "BROKEN" as a dep). It's unclear whether this could even function
  today in its current form but it has it's own .c file and Kconfig
  entry which is a bit more involved to remove and might make a come
  back?
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].

Also, this helps with the ongoing efforts to enable -Warray-bounds by
fixing the following warning:

  CC [M]  fs/cifs/cifssmb.o
fs/cifs/cifssmb.c: In function ‘CIFSFindNext’:
fs/cifs/cifssmb.c:4636:23: warning: array subscript 1 is above array bounds of ‘char[1]’ [-Warray-bounds]
 4636 |   pSMB->ResumeFileName[name_len+1] = 0;
      |   ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/109Signed-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

struct cifs_writedata is declared twice.
One is declared at 209th line.
And struct cifs_writedata is defined blew.
The declaration hear is not needed. Remove the duplicate.
Signed-off-by: NWan Jiabing <wanjiabing@vivo.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>