ksmbd: Fix dangling pointer in krb_authenticate

commit 1e440d5b25b7efccb3defe542a73c51005799a5f upstream.

krb_authenticate frees sess->user and does not set the pointer
to NULL. It calls ksmbd_krb5_authenticate to reinitialise
sess->user but that function may return without doing so. If
that happens then smb2_sess_setup, which calls krb_authenticate,
will be accessing free'd memory when it later uses sess->user.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sean Heelan
2025-04-07 11:26:50 +00:00
committed by Greg Kroah-Hartman
parent f95a2ec3ec
commit d5b554bc8d

View File

@@ -1615,8 +1615,10 @@ static int krb5_authenticate(struct ksmbd_work *work,
if (prev_sess_id && prev_sess_id != sess->id)
destroy_previous_session(conn, sess->user, prev_sess_id);
if (sess->state == SMB2_SESSION_VALID)
if (sess->state == SMB2_SESSION_VALID) {
ksmbd_free_user(sess->user);
sess->user = NULL;
}
retval = ksmbd_krb5_authenticate(sess, in_blob, in_len,
out_blob, &out_len);