Commit Graph

21 Commits

Author SHA1 Message Date
Eric Biggers
cc92b479b6 ksmbd: Use AES-CMAC library for SMB3 signature calculation
Now that AES-CMAC has a library API, convert ksmbd_sign_smb3_pdu() to
use it instead of a "cmac(aes)" crypto_shash.

The result is simpler and faster code.  With the library there's no need
to dynamically allocate memory, no need to handle errors, and the
AES-CMAC code is accessed directly without inefficient indirect calls
and other unnecessary API overhead.

Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2026-04-22 08:11:23 -05:00
Joshua Klinesmith
3e298897f4 ksmbd: fix use-after-free from async crypto on Qualcomm crypto engine
ksmbd_crypt_message() sets a NULL completion callback on AEAD requests
and does not handle the -EINPROGRESS return code from async hardware
crypto engines like the Qualcomm Crypto Engine (QCE). When QCE returns
-EINPROGRESS, ksmbd treats it as an error and immediately frees the
request while the hardware DMA operation is still in flight. The DMA
completion callback then dereferences freed memory, causing a NULL
pointer crash:

  pc : qce_skcipher_done+0x24/0x174
  lr : vchan_complete+0x230/0x27c
  ...
  el1h_64_irq+0x68/0x6c
  ksmbd_free_work_struct+0x20/0x118 [ksmbd]
  ksmbd_exit_file_cache+0x694/0xa4c [ksmbd]

Use the standard crypto_wait_req() pattern with crypto_req_done() as
the completion callback, matching the approach used by the SMB client
in fs/smb/client/smb2ops.c. This properly handles both synchronous
engines (immediate return) and async engines (-EINPROGRESS followed
by callback notification).

Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Link: https://github.com/openwrt/openwrt/issues/21822
Signed-off-by: Joshua Klinesmith <joshuaklinesmith@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2026-04-12 18:07:55 -05:00
Thorsten Blum
441336115d ksmbd: Don't log keys in SMB3 signing and encryption key generation
When KSMBD_DEBUG_AUTH logging is enabled, generate_smb3signingkey() and
generate_smb3encryptionkey() log the session, signing, encryption, and
decryption key bytes. Remove the logs to avoid exposing credentials.

Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2026-03-08 21:28:39 -05:00
Eric Biggers
c5794709bc ksmbd: Compare MACs in constant time
To prevent timing attacks, MAC comparisons need to be constant-time.
Replace the memcmp() with the correct function, crypto_memneq().

Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2026-02-22 21:27:28 -06:00
Kees Cook
69050f8d6d treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21 01:02:28 -08:00
Namjae Jeon
0b444cfd8b ksmbd: rename smb2_get_msg to smb_get_msg
With the removal of the RFC1002 length field from the SMB header,
smb2_get_msg is now used to get the smb1 request from the request buffer.
Since this function is no longer exclusive to smb2 and now supports smb1
as well, This patch rename it to smb_get_msg to better reflect its usage.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-12-21 19:20:46 -06:00
Eric Biggers
3a597e6e97 ksmbd: Use HMAC-MD5 library for NTLMv2
For the HMAC-MD5 computations in NTLMv2, use the HMAC-MD5 library
instead of a "hmac(md5)" crypto_shash.  This is simpler and faster.
With the library there's no need to allocate memory, no need to handle
errors, and the HMAC-MD5 code is accessed directly without inefficient
indirect calls and other unnecessary API overhead.

To preserve the existing behavior of NTLMv2 support being disabled when
the kernel is booted with "fips=1", make ksmbd_auth_ntlmv2() check
fips_enabled itself.  Previously it relied on the error from
crypto_alloc_shash("hmac(md5)") being bubbled up.  I don't know for sure
that this is actually needed, but this preserves the existing behavior.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-11-30 21:11:43 -06:00
Eric Biggers
924067ef18 ksmbd: Use HMAC-SHA256 library for message signing and key generation
Convert ksmbd_sign_smb2_pdu() and generate_key() to use the HMAC-SHA256
library instead of a "hmac(sha256)" crypto_shash.  This is simpler and
faster.  With the library there's no need to allocate memory, no need to
handle errors, and the HMAC-SHA256 code is accessed directly without
inefficient indirect calls and other unnecessary API overhead.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-11-30 21:11:43 -06:00
Eric Biggers
e009cb1e30 ksmbd: Use SHA-512 library for SMB3.1.1 preauth hash
Convert ksmbd_gen_preauth_integrity_hash() to use the SHA-512 library
instead of a "sha512" crypto_shash.  This is simpler and faster.  With
the library there's no need to allocate memory, no need to handle
errors, and the SHA-512 code is accessed directly without inefficient
indirect calls and other unnecessary API overhead.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-11-30 21:11:42 -06:00
Eric Biggers
8e979aab34 smb: Use arc4 library instead of duplicate arc4 code
fs/smb/common/cifs_arc4.c has an implementation of ARC4, but a copy of
this same code is also present in lib/crypto/arc4.c to serve the other
users of this legacy algorithm in the kernel.  Remove the duplicate
implementation in fs/smb/, which seems to have been added because of a
misunderstanding, and just use the lib/crypto/ one.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-09-29 21:21:23 -05:00
Eric Biggers
eb21736021 ksmbd: use SHA-256 library API instead of crypto_shash API
ksmbd_gen_sd_hash() does not support any other algorithm, so the
crypto_shash abstraction provides no value.  Just use the SHA-256
library API instead, which is much simpler and easier to use.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-05-25 22:54:50 -05:00
Sean Heelan
e86e9134e1 ksmbd: fix use-after-free in kerberos authentication
Setting sess->user = NULL was introduced to fix the dangling pointer
created by ksmbd_free_user. However, it is possible another thread could
be operating on the session and make use of sess->user after it has been
passed to ksmbd_free_user but before sess->user is set to NULL.

Cc: stable@vger.kernel.org
Signed-off-by: Sean Heelan <seanheelan@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-04-25 18:22:01 -05:00
Namjae Jeon
fa4cdb8cbc ksmbd: fix session use-after-free in multichannel connection
There is a race condition between session setup and
ksmbd_sessions_deregister. The session can be freed before the connection
is added to channel list of session.
This patch check reference count of session before freeing it.

Cc: stable@vger.kernel.org
Reported-by: Sean Heelan <seanheelan@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-04-01 00:04:21 -05:00
Miaoqian Lin
6171063e9d ksmbd: use aead_request_free to match aead_request_alloc
Use aead_request_free() instead of kfree() to properly free memory
allocated by aead_request_alloc(). This ensures sensitive crypto data
is zeroed before being freed.

Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-27 19:12:00 -05:00
Namjae Jeon
b95629435b ksmbd: fix racy issue from session lookup and expire
Increment the session reference count within the lock for lookup to avoid
racy issue with session expire.

Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-25737
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-12-10 17:48:06 -06:00
Namjae Jeon
0066f623bc ksmbd: use __GFP_RETRY_MAYFAIL
Prefer to report ENOMEM rather than incur the oom for allocations in
ksmbd. __GFP_NORETRY could not achieve that, It would fail the allocations
just too easily. __GFP_RETRY_MAYFAIL will keep retrying the allocation
until there is no more progress and fail the allocation instead go OOM
and let the caller to deal with it.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-11-25 18:58:02 -06:00
Namjae Jeon
a77e0e02af ksmbd: add support for supplementary groups
Even though system user has a supplementary group, It gets
NT_STATUS_ACCESS_DENIED when attempting to create file or directory.
This patch add KSMBD_EVENT_LOGIN_REQUEST_EXT/RESPONSE_EXT netlink events
to get supplementary groups list. The new netlink event doesn't break
backward compatibility when using old ksmbd-tools.

Co-developed-by: Atte Heikkilä <atteh.mailbox@gmail.com>
Signed-off-by: Atte Heikkilä <atteh.mailbox@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-10-11 11:02:14 -05:00
Randy Dunlap
b4068f1ef3 ksmbd: auth: fix most kernel-doc warnings
Fix 12 of 17 kernel-doc warnings in auth.c:

auth.c:221: warning: Function parameter or member 'conn' not described in 'ksmbd_auth_ntlmv2'
auth.c:221: warning: Function parameter or member 'cryptkey' not described in 'ksmbd_auth_ntlmv2'
auth.c:305: warning: Function parameter or member 'blob_len' not described in 'ksmbd_decode_ntlmssp_auth_blob'
auth.c:305: warning: Function parameter or member 'conn' not described in 'ksmbd_decode_ntlmssp_auth_blob'
auth.c:305: warning: Excess function parameter 'usr' description in 'ksmbd_decode_ntlmssp_auth_blob'
auth.c:385: warning: Function parameter or member 'blob_len' not described in 'ksmbd_decode_ntlmssp_neg_blob'
auth.c:385: warning: Function parameter or member 'conn' not described in 'ksmbd_decode_ntlmssp_neg_blob'
auth.c:385: warning: Excess function parameter 'rsp' description in 'ksmbd_decode_ntlmssp_neg_blob'
auth.c:385: warning: Excess function parameter 'sess' description in 'ksmbd_decode_ntlmssp_neg_blob'
auth.c:413: warning: Function parameter or member 'conn' not described in 'ksmbd_build_ntlmssp_challenge_blob'
auth.c:413: warning: Excess function parameter 'rsp' description in 'ksmbd_build_ntlmssp_challenge_blob'
auth.c:413: warning: Excess function parameter 'sess' description in 'ksmbd_build_ntlmssp_challenge_blob'

The other 5 are only present when a W=1 kernel build is done or
when scripts/kernel-doc is run with -Wall. They are:

auth.c:81: warning: No description found for return value of 'ksmbd_gen_sess_key'
auth.c:385: warning: No description found for return value of 'ksmbd_decode_ntlmssp_neg_blob'
auth.c:413: warning: No description found for return value of 'ksmbd_build_ntlmssp_challenge_blob'
auth.c:577: warning: No description found for return value of 'ksmbd_sign_smb2_pdu'
auth.c:628: warning: No description found for return value of 'ksmbd_sign_smb3_pdu'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <sfrench@samba.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-01-09 12:52:33 -06:00
Namjae Jeon
4b081ce0d8 ksmbd: fix slub overflow in ksmbd_decode_ntlmssp_auth_blob()
If authblob->SessionKey.Length is bigger than session key
size(CIFS_KEY_SIZE), slub overflow can happen in key exchange codes.
cifs_arc4_crypt copy to session key array from SessionKey from client.

Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-21940
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-08-29 12:30:20 -05:00
Namjae Jeon
e2b76ab8b5 ksmbd: add support for read compound
MacOS sends a compound request including read to the server
(e.g. open-read-close). So far, ksmbd has not handled read as
a compound request. For compatibility between ksmbd and an OS that
supports SMB, This patch provides compound support for read requests.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-08-29 12:30:19 -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