From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4AAE02D5C76; Tue, 12 Aug 2025 17:54:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755021281; cv=none; b=bzPkg5dYYrEk18js/oRkySd/9jmJ8rPzH2l9q/dhrGDnZIpZAZkEYNSaaPAjyRe2ZgYQjjCDIOXMe677TcSAsNk5iWnBCFUSgSwkl0rPSeI/1k8awg5omCTRvFbBT6vEWJxnSGtvQglHv/TS33EInWIzJd8k2Fq0FvjA+dwj+W4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755021281; c=relaxed/simple; bh=FTsYD5cuNLu4ihVvRm/MLI6R29yZlnkeNOi9bCdCvn0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JzUDn+qlTGxypGTtBiDzsrWYiKrFajnQwXtHioJRXF3NuXHnYIIpWfC58MGJszCuRDuqWFcQCBQXivcs9OjL8o6G0ZGZ9gSTsMIR0NhJmRFKk31i1yyjpcMVterqMrjM4HWtZoBX5hBwhJRktrip6lAd5RncdOYR020VFiLZLmI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Y/wMgdeM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Y/wMgdeM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF926C4CEF0; Tue, 12 Aug 2025 17:54:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1755021281; bh=FTsYD5cuNLu4ihVvRm/MLI6R29yZlnkeNOi9bCdCvn0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y/wMgdeMlkyd5D3CMvjYWJ5YTyDiHMEhl4MjvO6IlxgomVi8FxJLRYDNi5IOYJbLh kmU6JJ7KyyvR59ETKjMJ+1tZeVhCu60EPyxbOuMT8HuMly56SAH70UaX6B8GLTiY9I OYtBHXZn8n/5m0oIqvF1PEfuuFkJVY0OmRsyuRsk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Namjae Jeon , Steve French , zdi-disclosures@trendmicro.com Subject: [PATCH 6.1 239/253] ksmbd: fix null pointer dereference error in generate_encryptionkey Date: Tue, 12 Aug 2025 19:30:27 +0200 Message-ID: <20250812172959.007356815@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250812172948.675299901@linuxfoundation.org> References: <20250812172948.675299901@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Namjae Jeon commit 9b493ab6f35178afd8d619800df9071992f715de upstream. 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 Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/smb/server/smb2pdu.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -1621,11 +1621,24 @@ static int krb5_authenticate(struct ksmb 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 ksmb sess->sign = false; } +binding_session: if (conn->dialect >= SMB30_PROT_ID) { chann = lookup_chann_list(sess, conn); if (!chann) {