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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull automount updates from Al Viro:
"Automount wart removal
A bunch of odd boilerplate gone from instances - the reason for
those was the need to protect the yet-to-be-attched mount from
mark_mounts_for_expiry() deciding to take it out.
But that's easy to detect and take care of in mark_mounts_for_expiry()
itself; no need to have every instance simulate mount being busy by
grabbing an extra reference to it, with finish_automount() undoing
that once it attaches that mount.
Should've done it that way from the very beginning... This is a
flagday change, thankfully there are very few instances.
vfs_submount() is gone - its sole remaining user (trace_automount)
had been switched to saner primitives"
* tag 'pull-automount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
kill vfs_submount()
saner calling conventions for ->d_automount()
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs directory lookup updates from Christian Brauner:
"This contains cleanups for the lookup_one*() family of helpers.
We expose a set of functions with names containing "lookup_one_len"
and others without the "_len". This difference has nothing to do with
"len". It's rater a historical accident that can be confusing.
The functions without "_len" take a "mnt_idmap" pointer. This is found
in the "vfsmount" and that is an important question when choosing
which to use: do you have a vfsmount, or are you "inside" the
filesystem. A related question is "is permission checking relevant
here?".
nfsd and cachefiles *do* have a vfsmount but *don't* use the non-_len
functions. They pass nop_mnt_idmap and refuse to work on filesystems
which have any other idmap.
This work changes nfsd and cachefile to use the lookup_one family of
functions and to explictily pass &nop_mnt_idmap which is consistent
with all other vfs interfaces used where &nop_mnt_idmap is explicitly
passed.
The remaining uses of the "_one" functions do not require permission
checks so these are renamed to be "_noperm" and the permission
checking is removed.
This series also changes these lookup function to take a qstr instead
of separate name and len. In many cases this simplifies the call"
* tag 'vfs-6.16-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
VFS: change lookup_one_common and lookup_noperm_common to take a qstr
Use try_lookup_noperm() instead of d_hash_and_lookup() outside of VFS
VFS: rename lookup_one_len family to lookup_noperm and remove permission check
cachefiles: Use lookup_one() rather than lookup_one_len()
nfsd: Use lookup_one() rather than lookup_one_len()
VFS: improve interface for lookup_one functions
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Multiple pointers in struct cifs_search_info (ntwrk_buf_start,
srch_entries_start, and last_entry) point to the same allocated buffer.
However, when freeing this buffer, only ntwrk_buf_start was set to NULL,
while the other pointers remained pointing to freed memory.
This is defensive programming to prevent potential issues with stale
pointers. While the active UAF vulnerability is fixed by the previous
patch, this change ensures consistent pointer state and more robust error
handling.
Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com>
Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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There is a race condition in the readdir concurrency process, which may
access the rsp buffer after it has been released, triggering the
following KASAN warning.
==================================================================
BUG: KASAN: slab-use-after-free in cifs_fill_dirent+0xb03/0xb60 [cifs]
Read of size 4 at addr ffff8880099b819c by task a.out/342975
CPU: 2 UID: 0 PID: 342975 Comm: a.out Not tainted 6.15.0-rc6+ #240 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x53/0x70
print_report+0xce/0x640
kasan_report+0xb8/0xf0
cifs_fill_dirent+0xb03/0xb60 [cifs]
cifs_readdir+0x12cb/0x3190 [cifs]
iterate_dir+0x1a1/0x520
__x64_sys_getdents+0x134/0x220
do_syscall_64+0x4b/0x110
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f996f64b9f9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89
f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01
f0 ff ff 0d f7 c3 0c 00 f7 d8 64 89 8
RSP: 002b:00007f996f53de78 EFLAGS: 00000207 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007f996f53ecdc RCX: 00007f996f64b9f9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f996f53dea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000207 R12: ffffffffffffff88
R13: 0000000000000000 R14: 00007ffc8cd9a500 R15: 00007f996f51e000
</TASK>
Allocated by task 408:
kasan_save_stack+0x20/0x40
kasan_save_track+0x14/0x30
__kasan_slab_alloc+0x6e/0x70
kmem_cache_alloc_noprof+0x117/0x3d0
mempool_alloc_noprof+0xf2/0x2c0
cifs_buf_get+0x36/0x80 [cifs]
allocate_buffers+0x1d2/0x330 [cifs]
cifs_demultiplex_thread+0x22b/0x2690 [cifs]
kthread+0x394/0x720
ret_from_fork+0x34/0x70
ret_from_fork_asm+0x1a/0x30
Freed by task 342979:
kasan_save_stack+0x20/0x40
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x37/0x50
kmem_cache_free+0x2b8/0x500
cifs_buf_release+0x3c/0x70 [cifs]
cifs_readdir+0x1c97/0x3190 [cifs]
iterate_dir+0x1a1/0x520
__x64_sys_getdents64+0x134/0x220
do_syscall_64+0x4b/0x110
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The buggy address belongs to the object at ffff8880099b8000
which belongs to the cache cifs_request of size 16588
The buggy address is located 412 bytes inside of
freed 16588-byte region [ffff8880099b8000, ffff8880099bc0cc)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x99b8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff888001e03400 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000010001 00000000f5000000 0000000000000000
head: 0080000000000040 ffff888001e03400 0000000000000000 dead000000000001
head: 0000000000000000 0000000000010001 00000000f5000000 0000000000000000
head: 0080000000000003 ffffea0000266e01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8880099b8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880099b8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880099b8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880099b8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880099b8280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
POC is available in the link [1].
The problem triggering process is as follows:
Process 1 Process 2
-----------------------------------------------------------------
cifs_readdir
/* file->private_data == NULL */
initiate_cifs_search
cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
smb2_query_dir_first ->query_dir_first()
SMB2_query_directory
SMB2_query_directory_init
cifs_send_recv
smb2_parse_query_directory
srch_inf->ntwrk_buf_start = (char *)rsp;
srch_inf->srch_entries_start = (char *)rsp + ...
srch_inf->last_entry = (char *)rsp + ...
srch_inf->smallBuf = true;
find_cifs_entry
/* if (cfile->srch_inf.ntwrk_buf_start) */
cifs_small_buf_release(cfile->srch_inf // free
cifs_readdir ->iterate_shared()
/* file->private_data != NULL */
find_cifs_entry
/* in while (...) loop */
smb2_query_dir_next ->query_dir_next()
SMB2_query_directory
SMB2_query_directory_init
cifs_send_recv
compound_send_recv
smb_send_rqst
__smb_send_rqst
rc = -ERESTARTSYS;
/* if (fatal_signal_pending()) */
goto out;
return rc
/* if (cfile->srch_inf.last_entry) */
cifs_save_resume_key()
cifs_fill_dirent // UAF
/* if (rc) */
return -ENOENT;
Fix this by ensuring the return code is checked before using pointers
from the srch_inf.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=220131 [1]
Fixes: a364bc0b37f1 ("[CIFS] fix saving of resume key before CIFSFindNext")
Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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cifs_prepare_read() might be called with a disconnected channel, where
TCP_Server_Info::max_read is set to zero due to reconnect, so calling
->negotiate_rize() will set @rsize to default min IO size (64KiB) and
then logging
CIFS: VFS: SMB: Zero rsize calculated, using minimum value
65536
If the reconnect happens in cifsd thread, cifs_renegotiate_iosize()
will end up being called and then @rsize set to the expected value.
Since we can't rely on the value of @server->max_read by the time we
call cifs_prepare_read(), try to ->negotiate_rize() only if
@cifs_sb->ctx->rsize is zero.
Reported-by: Steve French <stfrench@microsoft.com>
Fixes: c59f7c9661b9 ("smb: client: ensure aligned IO sizes")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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The response buffer for the CREATE request handled by smb311_posix_mkdir()
is leaked on the error path (goto err_free_rsp_buf) because the structure
pointer *rsp passed to free_rsp_buf() is not assigned until *after* the
error condition is checked.
As *rsp is initialised to NULL, free_rsp_buf() becomes a no-op and the leak
is instead reported by __kmem_cache_shutdown() upon subsequent rmmod of
cifs.ko if (and only if) the error path has been hit.
Pass rsp_iov.iov_base to free_rsp_buf() instead, similar to the code in
other functions in smb2pdu.c for which *rsp is assigned late.
Cc: stable@vger.kernel.org
Signed-off-by: Jethro Donaldson <devel@jro.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
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A pre-existing valid cfid returned from find_or_create_cached_dir might
race with a lease break, meaning open_cached_dir doesn't consider it
valid, and thinks it's newly-constructed. This leaks a dentry reference
if the allocation occurs before the queued lease break work runs.
Avoid the race by extending holding the cfid_list_lock across
find_or_create_cached_dir and when the result is checked.
Cc: stable@vger.kernel.org
Reviewed-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Paul Aurich <paul@darkrain42.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Coverity noticed that the rc on smb2_parse_contexts() was not being checked
in the case of compounded operations. Since we don't want to stop parsing
the following compounded responses which are likely valid, we can't easily
error out here, but at least print a warning message if server has a bug
causing us to skip parsing the open response contexts.
Addresses-Coverity: 1639191
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Currently the calling conventions for ->d_automount() instances have
an odd wart - returned new mount to be attached is expected to have
refcount 2.
That kludge is intended to make sure that mark_mounts_for_expiry() called
before we get around to attaching that new mount to the tree won't decide
to take it out. finish_automount() drops the extra reference after it's
done with attaching mount to the tree - or drops the reference twice in
case of error. ->d_automount() instances have rather counterintuitive
boilerplate in them.
There's a much simpler approach: have mark_mounts_for_expiry() skip the
mounts that are yet to be mounted. And to hell with grabbing/dropping
those extra references. Makes for simpler correctness analysis, at that...
Reviewed-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Acked-by: David Howells <dhowells@redhat.com>
Tested-by: David Howells <dhowells@redhat.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Make all IO sizes multiple of PAGE_SIZE, either negotiated by the
server or passed through rsize, wsize and bsize mount options, to
prevent from breaking DIO reads and writes against servers that
enforce alignment as specified in MS-FSA 2.1.5.3 and 2.1.5.4.
Cc: linux-cifs@vger.kernel.org
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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function
Function CIFSSMBSetPathInfo() is not supported by non-NT servers and
returns error. Fallback code via open filehandle and CIFSSMBSetFileInfo()
does not work neither because CIFS_open() works also only on NT server.
Therefore currently the whole smb_set_file_info() function as a SMB1
callback for the ->set_file_info() does not work with older non-NT SMB
servers, like Win9x and others.
This change implements fallback code in smb_set_file_info() which will
works with any server and allows to change time values and also to set or
clear read-only attributes.
To make existing fallback code via CIFSSMBSetFileInfo() working with also
non-NT servers, it is needed to change open function from CIFS_open()
(which is NT specific) to cifs_open_file() which works with any server
(this is just a open wrapper function which choose the correct open
function supported by the server).
CIFSSMBSetFileInfo() is working also on non-NT servers, but zero time
values are not treated specially. So first it is needed to fill all time
values if some of them are missing, via cifs_query_path_info() call.
There is another issue, opening file in write-mode (needed for changing
attributes) is not possible when the file has read-only attribute set.
The only option how to clear read-only attribute is via SMB_COM_SETATTR
command. And opening directory is not possible neither and here the
SMB_COM_SETATTR command is the only option how to change attributes.
And CIFSSMBSetFileInfo() does not honor setting read-only attribute, so
for setting is also needed to use SMB_COM_SETATTR command.
Existing code in cifs_query_path_info() is already using SMB_COM_GETATTR as
a fallback code path (function SMBQueryInformation()), so introduce a new
function SMBSetInformation which will implement SMB_COM_SETATTR command.
My testing showed that Windows XP SMB1 client is also using SMB_COM_SETATTR
command for setting or clearing read-only attribute against non-NT server.
So this can prove that this is the correct way how to do it.
With this change it is possible set all 4 time values and all attributes,
including clearing and setting read-only bit on non-NT SMB servers.
Tested against Win98 SMB1 server.
This change fixes "touch" command which was failing when called on existing
file. And fixes also "chmod +w" and "chmod -w" commands which were also
failing (as they are changing read-only attribute).
Note that this change depends on following change
"cifs: Improve cifs_query_path_info() and cifs_query_file_info()"
as it require to query all 4 time attribute values.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
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When CAP_NT_SMBS was not negotiated then do not issue CIFSSMBQPathInfo()
and CIFSSMBQFileInfo() commands. CIFSSMBQPathInfo() is not supported by
non-NT Win9x SMB server and CIFSSMBQFileInfo() returns from Win9x SMB
server bogus data in Attributes field (for example lot of files are marked
as reparse points, even Win9x does not support them and read-only bit is
not marked for read-only files). Correct information is returned by
CIFSFindFirst() or SMBQueryInformation() command.
So as a fallback in cifs_query_path_info() function use CIFSFindFirst()
with SMB_FIND_FILE_FULL_DIRECTORY_INFO level which is supported by both NT
and non-NT servers and as a last option use SMBQueryInformation() as it was
before.
And in function cifs_query_file_info() immediately returns -EOPNOTSUPP when
not communicating with NT server. Client then revalidate inode entry by the
cifs_query_path_info() call, which is working fine. So fstat() syscall on
already opened file will receive correct information.
Note that both fallback functions in non-UNICODE mode expands wildcards.
Therefore those fallback functions cannot be used on paths which contain
SMB wildcard characters (* ? " > <).
CIFSFindFirst() returns all 4 time attributes as opposite of
SMBQueryInformation() which returns only one.
With this change it is possible to query all 4 times attributes from Win9x
server and at the same time, client minimize sending of unsupported
commands to server.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
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SMB create requests issued via smb311_posix_mkdir() have an incorrect
length of zero bytes for the POSIX create context data. ksmbd server
rejects such requests and logs "cli req too short" causing mkdir to fail
with "invalid argument" on the client side. It also causes subsequent
rmmod to crash in cifs_destroy_request_bufs()
Inspection of packets sent by cifs.ko using wireshark show valid data for
the SMB2_POSIX_CREATE_CONTEXT is appended with the correct offset, but
with an incorrect length of zero bytes. Fails with ksmbd+cifs.ko only as
Windows server/client does not use POSIX extensions.
Fix smb311_posix_mkdir() to set req->CreateContextsLength as part of
appending the POSIX creation context to the request.
Signed-off-by: Jethro Donaldson <devel@jro.nz>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
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This reverts commit e9f2517a3e18a54a3943c098d2226b245d488801.
Commit e9f2517a3e18 ("smb: client: fix TCP timers deadlock after
rmmod") is intended to fix a null-ptr-deref in LOCKDEP, which is
mentioned as CVE-2024-54680, but is actually did not fix anything;
The issue can be reproduced on top of it. [0]
Also, it reverted the change by commit ef7134c7fc48 ("smb: client:
Fix use-after-free of network namespace.") and introduced a real
issue by reviving the kernel TCP socket.
When a reconnect happens for a CIFS connection, the socket state
transitions to FIN_WAIT_1. Then, inet_csk_clear_xmit_timers_sync()
in tcp_close() stops all timers for the socket.
If an incoming FIN packet is lost, the socket will stay at FIN_WAIT_1
forever, and such sockets could be leaked up to net.ipv4.tcp_max_orphans.
Usually, FIN can be retransmitted by the peer, but if the peer aborts
the connection, the issue comes into reality.
I warned about this privately by pointing out the exact report [1],
but the bogus fix was finally merged.
So, we should not stop the timers to finally kill the connection on
our side in that case, meaning we must not use a kernel socket for
TCP whose sk->sk_net_refcnt is 0.
The kernel socket does not have a reference to its netns to make it
possible to tear down netns without cleaning up every resource in it.
For example, tunnel devices use a UDP socket internally, but we can
destroy netns without removing such devices and let it complete
during exit. Otherwise, netns would be leaked when the last application
died.
However, this is problematic for TCP sockets because TCP has timers to
close the connection gracefully even after the socket is close()d. The
lifetime of the socket and its netns is different from the lifetime of
the underlying connection.
If the socket user does not maintain the netns lifetime, the timer could
be fired after the socket is close()d and its netns is freed up, resulting
in use-after-free.
Actually, we have seen so many similar issues and converted such sockets
to have a reference to netns.
That's why I converted the CIFS client socket to have a reference to
netns (sk->sk_net_refcnt == 1), which is somehow mentioned as out-of-scope
of CIFS and technically wrong in e9f2517a3e18, but **is in-scope and right
fix**.
Regarding the LOCKDEP issue, we can prevent the module unload by
bumping the module refcount when switching the LOCKDDEP key in
sock_lock_init_class_and_name(). [2]
For a while, let's revert the bogus fix.
Note that now we can use sk_net_refcnt_upgrade() for the socket
conversion, but I'll do so later separately to make backport easy.
Link: https://lore.kernel.org/all/20250402020807.28583-1-kuniyu@amazon.com/ #[0]
Link: https://lore.kernel.org/netdev/c08bd5378da647a2a4c16698125d180a@huawei.com/ #[1]
Link: https://lore.kernel.org/lkml/20250402005841.19846-1-kuniyu@amazon.com/ #[2]
Fixes: e9f2517a3e18 ("smb: client: fix TCP timers deadlock after rmmod")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
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use-after-free"
This reverts commit 4e7f1644f2ac6d01dc584f6301c3b1d5aac4eaef.
The commit e9f2517a3e18 ("smb: client: fix TCP timers deadlock after
rmmod") is not only a bogus fix for LOCKDEP null-ptr-deref but also
introduces a real issue, TCP sockets leak, which will be explained in
detail in the next revert.
Also, CNA assigned CVE-2024-54680 to it but is rejecting it. [0]
Thus, we are reverting the commit and its follow-up commit 4e7f1644f2ac
("smb: client: Fix netns refcount imbalance causing leaks and
use-after-free").
Link: https://lore.kernel.org/all/2025040248-tummy-smilingly-4240@gregkh/ #[0]
Fixes: 4e7f1644f2ac ("smb: client: Fix netns refcount imbalance causing leaks and use-after-free")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
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The following Python script results in unexpected behaviour when run on
a CIFS filesystem against a Windows Server:
# Create file
fd = os.open('test', os.O_WRONLY|os.O_CREAT)
os.write(fd, b'foo')
os.close(fd)
# Open and close the file to leave a pending deferred close
fd = os.open('test', os.O_RDONLY|os.O_DIRECT)
os.close(fd)
# Try to open the file via a hard link
os.link('test', 'new')
newfd = os.open('new', os.O_RDONLY|os.O_DIRECT)
The final open returns EINVAL due to the server returning
STATUS_INVALID_PARAMETER. The root cause of this is that the client
caches lease keys per inode, but the spec requires them to be related to
the filename which causes problems when hard links are involved:
From MS-SMB2 section 3.3.5.9.11:
"The server MUST attempt to locate a Lease by performing a lookup in the
LeaseTable.LeaseList using the LeaseKey in the
SMB2_CREATE_REQUEST_LEASE_V2 as the lookup key. If a lease is found,
Lease.FileDeleteOnClose is FALSE, and Lease.Filename does not match the
file name for the incoming request, the request MUST be failed with
STATUS_INVALID_PARAMETER"
On client side, we first check the context of file open, if it hits above
conditions, we first close all opening files which are belong to the same
inode, then we do open the hard link file.
Cc: stable@vger.kernel.org
Signed-off-by: Chunjie Zhu <chunjie.zhu@cloud.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Two new file system attributes were recently added. See MS-FSCC 2.5.1:
FILE_SUPPORTS_POSIX_UNLINK_RENAME and
FILE_RETURNS_CLEANUP_RESULT_INFO
Update the missing defines for ksmbd and cifs.ko
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
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When reparse point in SMB1 query_path_info() callback was detected then
query also for EA $LXDEV. In this EA are stored device major and minor
numbers used by WSL CHR and BLK reparse points. Without major and minor
numbers, stat() syscall does not work for char and block devices.
Similar code is already in SMB2+ query_path_info() callback function.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
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buffer
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>
|
|
Like previous changes for file inode.c, handle directory name surrogate
reparse points generally also in reparse.c.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
IO_REPARSE_TAG_MOUNT_POINT is just a specific case of directory Name
Surrogate reparse point. As reparse_info_to_fattr() already handles all
directory Name Surrogate reparse point (done by the previous change),
there is no need to have explicit case for IO_REPARSE_TAG_MOUNT_POINT.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
Like in UNICODE mode, SMB1 Session Setup Kerberos Request contains oslm and
domain strings.
Extract common code into ascii_oslm_strings() and ascii_domain_string()
functions (similar to unicode variants) and use these functions in
non-UNICODE code path in sess_auth_kerberos().
Decision if non-UNICODE or UNICODE mode is used is based on the
SMBFLG2_UNICODE flag in Flags2 packed field, and not based on the
capabilities of server. Fix this check too.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
After commit f7025d861694 ("smb: client: allocate crypto only for
primary server") and commit b0abcd65ec54 ("smb: client: fix UAF in
async decryption"), the channels started reusing AEAD TFM from primary
channel to perform synchronous decryption, but that can't done as
there could be multiple cifsd threads (one per channel) simultaneously
accessing it to perform decryption.
This fixes the following KASAN splat when running fstest generic/249
with 'vers=3.1.1,multichannel,max_channels=4,seal' against Windows
Server 2022:
BUG: KASAN: slab-use-after-free in gf128mul_4k_lle+0xba/0x110
Read of size 8 at addr ffff8881046c18a0 by task cifsd/986
CPU: 3 UID: 0 PID: 986 Comm: cifsd Not tainted 6.15.0-rc1 #1
PREEMPT(voluntary)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-3.fc41
04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x5d/0x80
print_report+0x156/0x528
? gf128mul_4k_lle+0xba/0x110
? __virt_addr_valid+0x145/0x300
? __phys_addr+0x46/0x90
? gf128mul_4k_lle+0xba/0x110
kasan_report+0xdf/0x1a0
? gf128mul_4k_lle+0xba/0x110
gf128mul_4k_lle+0xba/0x110
ghash_update+0x189/0x210
shash_ahash_update+0x295/0x370
? __pfx_shash_ahash_update+0x10/0x10
? __pfx_shash_ahash_update+0x10/0x10
? __pfx_extract_iter_to_sg+0x10/0x10
? ___kmalloc_large_node+0x10e/0x180
? __asan_memset+0x23/0x50
crypto_ahash_update+0x3c/0xc0
gcm_hash_assoc_remain_continue+0x93/0xc0
crypt_message+0xe09/0xec0 [cifs]
? __pfx_crypt_message+0x10/0x10 [cifs]
? _raw_spin_unlock+0x23/0x40
? __pfx_cifs_readv_from_socket+0x10/0x10 [cifs]
decrypt_raw_data+0x229/0x380 [cifs]
? __pfx_decrypt_raw_data+0x10/0x10 [cifs]
? __pfx_cifs_read_iter_from_socket+0x10/0x10 [cifs]
smb3_receive_transform+0x837/0xc80 [cifs]
? __pfx_smb3_receive_transform+0x10/0x10 [cifs]
? __pfx___might_resched+0x10/0x10
? __pfx_smb3_is_transform_hdr+0x10/0x10 [cifs]
cifs_demultiplex_thread+0x692/0x1570 [cifs]
? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs]
? rcu_is_watching+0x20/0x50
? rcu_lockdep_current_cpu_online+0x62/0xb0
? find_held_lock+0x32/0x90
? kvm_sched_clock_read+0x11/0x20
? local_clock_noinstr+0xd/0xd0
? trace_irq_enable.constprop.0+0xa8/0xe0
? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs]
kthread+0x1fe/0x380
? kthread+0x10f/0x380
? __pfx_kthread+0x10/0x10
? local_clock_noinstr+0xd/0xd0
? ret_from_fork+0x1b/0x60
? local_clock+0x15/0x30
? lock_release+0x29b/0x390
? rcu_is_watching+0x20/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork+0x31/0x60
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Tested-by: David Howells <dhowells@redhat.com>
Reported-by: Steve French <stfrench@microsoft.com>
Closes: https://lore.kernel.org/r/CAH2r5mu6Yc0-RJXM3kFyBYUB09XmXBrNodOiCVR4EDrmxq5Szg@mail.gmail.com
Fixes: f7025d861694 ("smb: client: allocate crypto only for primary server")
Fixes: b0abcd65ec54 ("smb: client: fix UAF in async decryption")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
MS-FSCC in section 2.1.2.7 LX SYMLINK REPARSE_DATA_BUFFER now contains
documentation about WSL symlink reparse point buffers.
https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-fscc/68337353-9153-4ee1-ac6b-419839c3b7ad
Fix the struct reparse_wsl_symlink_data_buffer to reflect buffer fields
according to the MS-FSCC documentation.
Fix the Linux SMB client to correctly fill the WSL symlink reparse point
buffer when creaing new WSL-style symlink. There was a mistake during
filling the data part of the reparse point buffer. It should starts with
bytes "\x02\x00\x00\x00" (which represents version 2) but this constant was
written as number 0x02000000 encoded in little endian, which resulted bytes
"\x00\x00\x00\x02". This change is fixing this mistake.
Fixes: 4e2043be5c14 ("cifs: Add support for creating WSL-style symlinks")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
try_lookup_noperm() and d_hash_and_lookup() are nearly identical. The
former does some validation of the name where the latter doesn't.
Outside of the VFS that validation is likely valuable, and having only
one exported function for this task is certainly a good idea.
So make d_hash_and_lookup() local to VFS files and change all other
callers to try_lookup_noperm(). Note that the arguments are swapped.
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250319031545.2999807-6-neil@brown.name
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
The lookup_one_len family of functions is (now) only used internally by
a filesystem on itself either
- in a context where permission checking is irrelevant such as by a
virtual filesystem populating itself, or xfs accessing its ORPHANAGE
or dquota accessing the quota file; or
- in a context where a permission check (MAY_EXEC on the parent) has just
been performed such as a network filesystem finding in "silly-rename"
file in the same directory. This is also the context after the
_parentat() functions where currently lookup_one_qstr_excl() is used.
So the permission check is pointless.
The name "one_len" is unhelpful in understanding the purpose of these
functions and should be changed. Most of the callers pass the len as
"strlen()" so using a qstr and QSTR() can simplify the code.
This patch renames these functions (include lookup_positive_unlocked()
which is part of the family despite the name) to have a name based on
"lookup_noperm". They are changed to receive a 'struct qstr' instead
of separate name and len. In a few cases the use of QSTR() results in a
new call to strlen().
try_lookup_noperm() takes a pointer to a qstr instead of the whole
qstr. This is consistent with d_hash_and_lookup() (which is nearly
identical) and useful for lookup_noperm_unlocked().
The new lookup_noperm_common() doesn't take a qstr yet. That will be
tidied up in a subsequent patch.
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://lore.kernel.org/r/20250319031545.2999807-5-neil@brown.name
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
When mounting the same share twice, once with the "linux" mount parameter
(or equivalently "posix") and then once without (or e.g. with "nolinux"),
we were incorrectly reusing the same tree connection for both mounts.
This meant that the first mount of the share on the client, would
cause subsequent mounts of that same share on the same client to
ignore that mount parm ("linux" vs. "nolinux") and incorrectly reuse
the same tcon.
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
the server
Fix regression in mounts to e.g. onedrive shares.
Generally, reparse points are processed by the SMB server during the
SMB OPEN request, but there are few reparse points which do not have
OPEN-like meaning for the SMB server and has to be processed by the SMB
client. Those are symlinks and special files (fifo, socket, block, char).
For Linux SMB client, it is required to process also name surrogate reparse
points as they represent another entity on the SMB server system. Linux
client will mark them as separate mount points. Examples of name surrogate
reparse points are NTFS junction points (e.g. created by the "mklink" tool
on Windows servers).
So after processing the name surrogate reparse points, clear the
-EOPNOTSUPP error code returned from the parse_reparse_point() to let SMB
server to process reparse points.
And remove printing misleading error message "unhandled reparse tag:" as
reparse points are handled by SMB server and hence unhandled fact is normal
operation.
Fixes: cad3fc0a4c8c ("cifs: Throw -EOPNOTSUPP error on unsupported reparse point type from parse_reparse_point()")
Fixes: b587fd128660 ("cifs: Treat unhandled directory name surrogate reparse points as mount directory nodes")
Cc: stable@vger.kernel.org
Reported-by: Junwen Sun <sunjw8888@gmail.com>
Tested-by: Junwen Sun <sunjw8888@gmail.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
To 2.52
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
This change allows Linux SMB1 client to autoreconnect the share when it is
modified on server by admin operation which removes and re-adds it.
Implementation is reused from SMB2+ is_network_name_deleted callback. There
are just adjusted checks for error codes and access to struct smb_hdr.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
The calls to cifs_truncate_page() should be superfluous as the places that
call it also call truncate_setsize() or cifs_setsize() and therefore
truncate_pagecache() which should also clear the tail part of the folio
containing the EOF marker.
Further, smb3_simple_falloc() calls both cifs_setsize() and
truncate_setsize() in addition to cifs_truncate_page().
Remove the superfluous calls.
This gets rid of another function referring to struct page.
[Should cifs_setsize() also set inode->i_blocks?]
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
Individual bits GENERIC_READ, GENERIC_EXECUTE and GENERIC_ALL have meaning
which includes also access right for FILE_READ_ATTRIBUTES. So specifying
FILE_READ_ATTRIBUTES bit together with one of those GENERIC (except
GENERIC_WRITE) does not do anything.
This change prevents calling additional (fallback) code and sending more
requests without FILE_READ_ATTRIBUTES when the primary request fails on
-EACCES, as it is not needed at all.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
If SMB2_OP_QUERY_INFO (called when POSIX extensions are not used) failed
with STATUS_ACCESS_DENIED then it means that caller does not have
permission to open the path with FILE_READ_ATTRIBUTES access and therefore
cannot issue SMB2_OP_QUERY_INFO command.
This will result in the -EACCES error from stat() sycall.
There is an alternative way how to query limited information about path but
still suitable for stat() syscall. SMB2 OPEN/CREATE operation returns in
its successful response subset of query information.
So try to open the path without FILE_READ_ATTRIBUTES but with
MAXIMUM_ALLOWED access which will grant the maximum possible access to the
file and the response will contain required query information for stat()
syscall.
This will improve smb2_query_path_info() to query also files which do not
grant FILE_READ_ATTRIBUTES access to caller.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
Some operations, like WRITE, does not require FILE_READ_ATTRIBUTES access.
So when FILE_READ_ATTRIBUTES is not explicitly requested for
smb2_open_file() then first try to do SMB2 CREATE with FILE_READ_ATTRIBUTES
access (like it was before) and then fallback to SMB2 CREATE without
FILE_READ_ATTRIBUTES access (less common case).
This change allows to complete WRITE operation to a file when it does not
grant FILE_READ_ATTRIBUTES permission and its parent directory does not
grant READ_DATA permission (parent directory READ_DATA is implicit grant of
child FILE_READ_ATTRIBUTES permission).
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
Old SMB1 servers without CAP_NT_SMBS do not support CIFS_open() function
and instead SMBLegacyOpen() needs to be used. This logic is already handled
in cifs_open_file() function, which is server->ops->open callback function.
So for querying and creating MF symlinks use open callback function instead
of CIFS_open() function directly.
This change fixes querying and creating new MF symlinks on Windows 98.
Currently cifs_query_mf_symlink() is not able to detect MF symlink and
cifs_create_mf_symlink() is failing with EIO error.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
When converting access_flags to SMBOPEN mode, check for all possible access
flags, not only GENERIC_READ and GENERIC_WRITE flags.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
SMB negotiate retry functionality in cifs_negotiate() is currently broken
and does not work when doing socket reconnect. Caller of this function,
which is cifs_negotiate_protocol() requires that tcpStatus after successful
execution of negotiate callback stay in CifsInNegotiate. But if the
CIFSSMBNegotiate() called from cifs_negotiate() fails due to connection
issues then tcpStatus is changed as so repeated CIFSSMBNegotiate() call
does not help.
Fix this problem by moving retrying code from negotiate callback (which is
either cifs_negotiate() or smb2_negotiate()) to cifs_negotiate_protocol()
which is caller of those callbacks. This allows to properly handle and
implement correct transistions between tcpStatus states as function
cifs_negotiate_protocol() already handles it.
With this change, cifs_negotiate_protocol() now handles also -EAGAIN error
set by the RFC1002_NEGATIVE_SESSION_RESPONSE processing after reconnecting
with NetBIOS session.
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>
|
|
Changing owner is controlled by DACL permission WRITE_OWNER. Changing DACL
itself is controlled by DACL permisssion WRITE_DAC. Owner of the file has
implicit WRITE_DAC permission even when it is not explicitly granted for
owner by DACL.
Reading DACL or owner is controlled only by one permission READ_CONTROL.
WRITE_OWNER permission can be bypassed by the SeTakeOwnershipPrivilege,
which is by default available for local administrators.
So if the local administrator wants to access some file to which does not
have access, it is required to first change owner to ourself and then
change DACL permissions.
Currently Linux SMB client does not support this because client does not
provide a way to change owner without touching DACL permissions.
Fix this problem by introducing a new xattr "system.smb3_ntsd_owner" for
setting/changing only owner part of the security descriptor.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
Access to SACL part of SMB security descriptor is granted by SACL privilege
which by default is accessible only for local administrator. But it can be
granted to any other user by local GPO or AD. SACL access is not granted by
DACL permissions and therefore is it possible that some user would not have
access to DACLs of some file, but would have access to SACLs of all files.
So it means that for accessing SACLs (either getting or setting) in some
cases requires not touching or asking for DACLs.
Currently Linux SMB client does not allow to get or set SACLs without
touching DACLs. Which means that user without DACL access is not able to
get or set SACLs even if it has access to SACLs.
Fix this problem by introducing a new xattr "system.smb3_ntsd_sacl" for
accessing only SACLs part of the security descriptor (therefore without
DACLs and OWNER/GROUP).
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
When a SMB connection is reset and reconnected, the negotiated IO
parameters (rsize/wsize) can become out of sync with the server's
current capabilities. This can lead to suboptimal performance or
even IO failures if the server's limits have changed.
This patch implements automatic IO size renegotiation:
1. Adds cifs_renegotiate_iosize() function to update all superblocks
associated with a tree connection
2. Updates each mount's rsize/wsize based on current server capabilities
3. Calls this function after successful tree connection reconnection
With this change, all mount points will automatically maintain optimal
and reliable IO parameters after network disruptions, using the
bidirectional mapping added in previous patches.
This completes the series improving connection resilience by keeping
mount parameters synchronized with server capabilities.
Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
During mount option processing and negotiation with the server, the
original user-specified rsize/wsize values were being modified directly.
This makes it impossible to recover these values after a connection
reset, leading to potential degraded performance after reconnection.
The other problem is that When negotiating read and write sizes, there are
cases where the negotiated values might calculate to zero, especially
during reconnection when server->max_read or server->max_write might be
reset. In general, these values come from the negotiation response.
According to MS-SMB2 specification, these values should be at least 65536
bytes.
This patch improves IO parameter handling:
1. Adds vol_rsize and vol_wsize fields to store the original user-specified
values separately from the negotiated values
2. Uses got_rsize/got_wsize flags to determine if values were
user-specified rather than checking for non-zero values, which is more
reliable
3. Adds a prevent_zero_iosize() helper function to ensure IO sizes are
never negotiated down to zero, which could happen in edge cases like
when server->max_read/write is zero
The changes make the CIFS client more resilient to unusual server
responses and reconnection scenarios, preventing potential failures
when IO sizes are calculated to be zero.
Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com>
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>
|
|
echo_interval is checked at mount time, the code has become
unreachable.
Signed-off-by: Roman Smirnov <r.smirnov@omp.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
The echo_interval is not limited in any way during mounting,
which makes it possible to write a large number to it. This can
cause an overflow when multiplying ctx->echo_interval by HZ in
match_server().
Add constraints for echo_interval to smb3_fs_context_parse_param().
Found by Linux Verification Center (linuxtesting.org) with Svace.
Fixes: adfeb3e00e8e1 ("cifs: Make echo interval tunable")
Cc: stable@vger.kernel.org
Signed-off-by: Roman Smirnov <r.smirnov@omp.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
git://git.samba.org/sfrench/cifs-2.6
Pull smb client updates from Steve French:
- Fix for network namespace refcount leak
- Multichannel fix and minor multichannel debug message cleanup
- Fix potential null ptr reference in SMB3 close
- Fix for special file handling when reparse points not supported by
server
- Two ACL fixes one for stricter ACE validation, one for incorrect
perms requested
- Three RFC1001 fixes: one for SMB3 mounts on port 139, one for better
default hostname, and one for better session response processing
- Minor update to email address for MAINTAINERS file
- Allow disabling Unicode for access to old SMB1 servers
- Three minor cleanups
* tag '6.15-rc-part1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
cifs: Add new mount option -o nounicode to disable SMB1 UNICODE mode
cifs: Set default Netbios RFC1001 server name to hostname in UNC
smb: client: Fix netns refcount imbalance causing leaks and use-after-free
cifs: add validation check for the fields in smb_aces
CIFS: Propagate min offload along with other parameters from primary to secondary channels.
cifs: Improve establishing SMB connection with NetBIOS session
cifs: Fix establishing NetBIOS session for SMB2+ connection
cifs: Fix getting DACL-only xattr system.cifs_acl and system.smb3_acl
cifs: Check if server supports reparse points before using them
MAINTAINERS: reorder preferred email for Steve French
cifs: avoid NULL pointer dereference in dbg call
smb: client: Remove redundant check in smb2_is_path_accessible()
smb: client: Remove redundant check in cifs_oplock_break()
smb: mark the new channel addition log as informational log with cifs_info
smb: minor cleanup to remove unused function declaration
|
|
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>
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Windows SMB servers (including SMB2+) which are working over RFC1001
require that Netbios server name specified in RFC1001 Session Request
packet is same as the UNC host name. Netbios server name can be already
specified manually via -o servern= option.
With this change the RFC1001 server name is set automatically by extracting
the hostname from the mount source.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Commit ef7134c7fc48 ("smb: client: Fix use-after-free of network
namespace.") attempted to fix a netns use-after-free issue by manually
adjusting reference counts via sk->sk_net_refcnt and sock_inuse_add().
However, a later commit e9f2517a3e18 ("smb: client: fix TCP timers deadlock
after rmmod") pointed out that the approach of manually setting
sk->sk_net_refcnt in the first commit was technically incorrect, as
sk->sk_net_refcnt should only be set for user sockets. It led to issues
like TCP timers not being cleared properly on close. The second commit
moved to a model of just holding an extra netns reference for
server->ssocket using get_net(), and dropping it when the server is torn
down.
But there remain some gaps in the get_net()/put_net() balancing added by
these commits. The incomplete reference handling in these fixes results
in two issues:
1. Netns refcount leaks[1]
The problem process is as follows:
```
mount.cifs cifsd
cifs_do_mount
cifs_mount
cifs_mount_get_session
cifs_get_tcp_session
get_net() /* First get net. */
ip_connect
generic_ip_connect /* Try port 445 */
get_net()
->connect() /* Failed */
put_net()
generic_ip_connect /* Try port 139 */
get_net() /* Missing matching put_net() for this get_net().*/
cifs_get_smb_ses
cifs_negotiate_protocol
smb2_negotiate
SMB2_negotiate
cifs_send_recv
wait_for_response
cifs_demultiplex_thread
cifs_read_from_socket
cifs_readv_from_socket
cifs_reconnect
cifs_abort_connection
sock_release();
server->ssocket = NULL;
/* Missing put_net() here. */
generic_ip_connect
get_net()
->connect() /* Failed */
put_net()
sock_release();
server->ssocket = NULL;
free_rsp_buf
...
clean_demultiplex_info
/* It's only called once here. */
put_net()
```
When cifs_reconnect() is triggered, the server->ssocket is released
without a corresponding put_net() for the reference acquired in
generic_ip_connect() before. it ends up calling generic_ip_connect()
again to retry get_net(). After that, server->ssocket is set to NULL
in the error path of generic_ip_connect(), and the net count cannot be
released in the final clean_demultiplex_info() function.
2. Potential use-after-free
The current refcounting scheme can lead to a potential use-after-free issue
in the following scenario:
```
cifs_do_mount
cifs_mount
cifs_mount_get_session
cifs_get_tcp_session
get_net() /* First get net */
ip_connect
generic_ip_connect
get_net()
bind_socket
kernel_bind /* failed */
put_net()
/* after out_err_crypto_release label */
put_net()
/* after out_err label */
put_net()
```
In the exception handling process where binding the socket fails, the
get_net() and put_net() calls are unbalanced, which may cause the
server->net reference count to drop to zero and be prematurely released.
To address both issues, this patch ties the netns reference counting to
the server->ssocket and server lifecycles. The extra reference is now
acquired when the server or socket is created, and released when the
socket is destroyed or the server is torn down.
[1]: https://bugzilla.kernel.org/show_bug.cgi?id=219792
Fixes: ef7134c7fc48 ("smb: client: Fix use-after-free of network namespace.")
Fixes: e9f2517a3e18 ("smb: client: fix TCP timers deadlock after rmmod")
Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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