ksmbd: fix Preauh_HashValue race condition

commit 44a3059c4c upstream.

If client send multiple session setup requests to ksmbd,
Preauh_HashValue race condition could happen.
There is no need to free sess->Preauh_HashValue at session setup phase.
It can be freed together with session at connection termination phase.

Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-27661
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Namjae Jeon 2025-07-25 08:13:31 +09:00 committed by Greg Kroah-Hartman
parent 9c2dbbc959
commit 6613887da1

View File

@ -1847,8 +1847,6 @@ int smb2_sess_setup(struct ksmbd_work *work)
ksmbd_conn_set_good(conn);
sess->state = SMB2_SESSION_VALID;
}
kfree(sess->Preauth_HashValue);
sess->Preauth_HashValue = NULL;
} else if (conn->preferred_auth_mech == KSMBD_AUTH_NTLMSSP) {
if (negblob->MessageType == NtLmNegotiate) {
rc = ntlm_negotiate(work, negblob, negblob_len, rsp);
@ -1875,8 +1873,6 @@ int smb2_sess_setup(struct ksmbd_work *work)
kfree(preauth_sess);
}
}
kfree(sess->Preauth_HashValue);
sess->Preauth_HashValue = NULL;
} else {
pr_info_ratelimited("Unknown NTLMSSP message type : 0x%x\n",
le32_to_cpu(negblob->MessageType));