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 CCED235C192 for ; Mon, 9 Mar 2026 10:22:46 +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=1773051766; cv=none; b=N4eAEVJCeBQovnh0kVt1binUuNokqg8TqbFaTA0OUmxylMNZK/AdsYZBel8dWaBgnKVxZ6zk/00yG7a41r3ERfnJPcKdQ82PnokdZrcgDL+rXcK4sruXrwG5d4Udz8l6+GfBeGKW+wAtZgFIJmVrK7jY179W9x1bXo2CTr1J9MA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773051766; c=relaxed/simple; bh=KP+F9mJvLoHKP3KOg8xWFmvepYNGNzq2VqvfSTY5bDE=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=GNIBl8YRi+GtY6KLPtRIhR3sWRijU0vB8dSh7dQkto87yP4qE9RcBVHhDu3NAz2n+Dp58bPa7DoaLqqk58BPa3XSjk8Z6w9h6uBezQd4S2tF7xazvBwiI44Qv/3Xr+xCpZbIaArvTej4br7qKbKuFDE1yoHWu5XdLiHc7E/ytcw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=G9QPMXsZ; 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="G9QPMXsZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 57275C4CEF7; Mon, 9 Mar 2026 10:22:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1773051766; bh=KP+F9mJvLoHKP3KOg8xWFmvepYNGNzq2VqvfSTY5bDE=; h=Subject:To:Cc:From:Date:From; b=G9QPMXsZ0xW5jsJ1Quib2jgWbgoAQ3fR1WD9OLWu7EvImsATLP1/k0j1JqK8sAmZ4 8uzU5okdtn37BpRtpd4xOFRPqEgREgzZ+t5HMJZyKfxYICfLh9lIriOry8VZzrGvEZ dBMO9Ie+U7AMj5SgSDky9CHaavQSNE42iVvz8PIY= Subject: FAILED: patch "[PATCH] ksmbd: Compare MACs in constant time" failed to apply to 6.6-stable tree To: ebiggers@kernel.org,linkinjeon@kernel.org,stfrench@microsoft.com Cc: From: Date: Mon, 09 Mar 2026 11:22:36 +0100 Message-ID: <2026030936-domelike-sinless-fe14@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x c5794709bc9105935dbedef8b9cf9c06f2b559fa # git commit -s git send-email --to '' --in-reply-to '2026030936-domelike-sinless-fe14@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From c5794709bc9105935dbedef8b9cf9c06f2b559fa Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 17 Feb 2026 20:28:29 -0800 Subject: [PATCH] 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: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Acked-by: Namjae Jeon Signed-off-by: Steve French diff --git a/fs/smb/server/Kconfig b/fs/smb/server/Kconfig index 2775162c535c..12594879cb64 100644 --- a/fs/smb/server/Kconfig +++ b/fs/smb/server/Kconfig @@ -13,6 +13,7 @@ config SMB_SERVER select CRYPTO_LIB_MD5 select CRYPTO_LIB_SHA256 select CRYPTO_LIB_SHA512 + select CRYPTO_LIB_UTILS select CRYPTO_CMAC select CRYPTO_AEAD2 select CRYPTO_CCM diff --git a/fs/smb/server/auth.c b/fs/smb/server/auth.c index 580c4d303dc3..5fe8c667c6b1 100644 --- a/fs/smb/server/auth.c +++ b/fs/smb/server/auth.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include @@ -165,7 +166,8 @@ int ksmbd_auth_ntlmv2(struct ksmbd_conn *conn, struct ksmbd_session *sess, ntlmv2_rsp, CIFS_HMAC_MD5_HASH_SIZE, sess->sess_key); - if (memcmp(ntlmv2->ntlmv2_hash, ntlmv2_rsp, CIFS_HMAC_MD5_HASH_SIZE) != 0) + if (crypto_memneq(ntlmv2->ntlmv2_hash, ntlmv2_rsp, + CIFS_HMAC_MD5_HASH_SIZE)) return -EINVAL; return 0; } diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 95901a78951c..743c629fe7ec 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -4,6 +4,7 @@ * Copyright (C) 2018 Samsung Electronics Co., Ltd. */ +#include #include #include #include @@ -8880,7 +8881,7 @@ int smb2_check_sign_req(struct ksmbd_work *work) ksmbd_sign_smb2_pdu(work->conn, work->sess->sess_key, iov, 1, signature); - if (memcmp(signature, signature_req, SMB2_SIGNATURE_SIZE)) { + if (crypto_memneq(signature, signature_req, SMB2_SIGNATURE_SIZE)) { pr_err("bad smb2 signature\n"); return 0; } @@ -8968,7 +8969,7 @@ int smb3_check_sign_req(struct ksmbd_work *work) if (ksmbd_sign_smb3_pdu(conn, signing_key, iov, 1, signature)) return 0; - if (memcmp(signature, signature_req, SMB2_SIGNATURE_SIZE)) { + if (crypto_memneq(signature, signature_req, SMB2_SIGNATURE_SIZE)) { pr_err("bad smb2 signature\n"); return 0; }