diff options
| author | Namjae Jeon <linkinjeon@kernel.org> | 2025-07-21 14:28:55 +0900 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2025-07-24 22:55:29 -0500 |
| commit | 9b493ab6f35178afd8d619800df9071992f715de (patch) | |
| tree | a98a202744827ffae53145d18bfaf13556b0cfce | |
| parent | 4e45cca31d4e70019a5e0fe15208de72f6a55a5e (diff) | |
ksmbd: fix null pointer dereference error in generate_encryptionkey
If client send two session setups with krb5 authenticate to ksmbd,
null pointer dereference error in generate_encryptionkey could happen.
sess->Preauth_HashValue is set to NULL if session is valid.
So this patch skip generate encryption key if session is valid.
Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-27654
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
| -rw-r--r-- | fs/smb/server/smb2pdu.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 929d62768f64..0caf30fb1df1 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -1621,11 +1621,24 @@ static int krb5_authenticate(struct ksmbd_work *work, rsp->SecurityBufferLength = cpu_to_le16(out_len); - if ((conn->sign || server_conf.enforced_signing) || + /* + * If session state is SMB2_SESSION_VALID, We can assume + * that it is reauthentication. And the user/password + * has been verified, so return it here. + */ + if (sess->state == SMB2_SESSION_VALID) { + if (conn->binding) + goto binding_session; + return 0; + } + + if ((rsp->SessionFlags != SMB2_SESSION_FLAG_IS_GUEST_LE && + (conn->sign || server_conf.enforced_signing)) || (req->SecurityMode & SMB2_NEGOTIATE_SIGNING_REQUIRED)) sess->sign = true; - if (smb3_encryption_negotiated(conn)) { + if (smb3_encryption_negotiated(conn) && + !(req->Flags & SMB2_SESSION_REQ_FLAG_BINDING)) { retval = conn->ops->generate_encryptionkey(conn, sess); if (retval) { ksmbd_debug(SMB, @@ -1638,6 +1651,7 @@ static int krb5_authenticate(struct ksmbd_work *work, sess->sign = false; } +binding_session: if (conn->dialect >= SMB30_PROT_ID) { chann = lookup_chann_list(sess, conn); if (!chann) { |