From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 423203DC4D9; Tue, 16 Jun 2026 18:39:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781635147; cv=none; b=fmcYrfbr+C2OZJ70/umPxhQjdG1FYGrbMS4YTBvGTRR4PO1c61I5BY0N0ASlm+uBHsH2HKiB+EM7RxBrFOLSPlh5u3TXlYKiRNOdfsLxJ77MD+vJOw+PVZ+7xy7F29cJFj0BSnH1LIfVM+znQQN3VV7+pbPEN+vBakD0hN9pVs8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781635147; c=relaxed/simple; bh=yMmM9YTH1MdsbCJ9HS5uEDA8qxWvlNnFvFaXFZemKLc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=m3ZyDEUOhw2AvSTl5LjBOZ0d/63I5F5ERIPrIRVduY0nUS2dVFSOCB5fTbHdbwvWqaTJ+iW4ZkFxVD+CSPewa/UCwv6V01P4KWZfWk7NY1DXFOrNl5Fcf9NclxAKmhbmYLjN2Hnan5WPRauZtvektCCdDqVfJCvmIB8l/emcyuc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ewNU/FLb; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ewNU/FLb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 39A851F000E9; Tue, 16 Jun 2026 18:39:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781635146; bh=g6Z/UdE6MNukNRuFAVCv2pv1Dozo16e944k78xhW8Yw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ewNU/FLbc/sfWthad/LdxxMuEBBZqH2PmVfRppDTGYKnEwuInWTtEB5q2PRN2S8BI a60ayIttkoPVA3unSDrCqVkPVq4s8lokZwUUn6r8eEJWfmP2iZjsbVc735yQkbviAt ts5fgz383qcvc3zWnGrUpQ/isXPWwVeHsoCRJE1Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Biggers , Namjae Jeon , Steve French Subject: [PATCH 5.15 398/411] ksmbd: Compare MACs in constant time Date: Tue, 16 Jun 2026 20:30:36 +0530 Message-ID: <20260616145122.350625413@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145100.376842714@linuxfoundation.org> References: <20260616145100.376842714@linuxfoundation.org> User-Agent: quilt/0.69 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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Biggers commit c5794709bc9105935dbedef8b9cf9c06f2b559fa upstream. 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 Signed-off-by: Greg Kroah-Hartman --- fs/ksmbd/auth.c | 4 +++- fs/ksmbd/smb2pdu.c | 5 +++-- 2 files changed, 6 insertions(+), 3 deletions(-) --- a/fs/ksmbd/auth.c +++ b/fs/ksmbd/auth.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include @@ -281,7 +282,8 @@ int ksmbd_auth_ntlmv2(struct ksmbd_conn goto out; } - 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)) rc = -EINVAL; out: if (ctx) --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -4,6 +4,7 @@ * Copyright (C) 2018 Samsung Electronics Co., Ltd. */ +#include #include #include #include @@ -8440,7 +8441,7 @@ int smb2_check_sign_req(struct ksmbd_wor 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; } @@ -8528,7 +8529,7 @@ int smb3_check_sign_req(struct ksmbd_wor 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; }