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 3EBC32571A1; Thu, 17 Apr 2025 18:51:16 +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=1744915876; cv=none; b=J9GwhDrJCp097btC539IwGUnWLAqYEoBTRLjL0U78GZMI0m8RvhzWo9BvzWC/q1zkXwmLU+/5kmHSiAoesJ4XR+TwFfCdcYvtgQn51XUkOiFNtnmF8Kdt+Vc1zrJlHbCZDx59QTbxCowVFFCWW55JTedjNlBVlHSOfkoHMYR+1A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744915876; c=relaxed/simple; bh=fhC3L1YMj/cN6dZuF3uyh4CNRyhTsbQtkPkE7XIIwLw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qRZ1A/Br3wgJgK0QDKTiS0O2lDJKnSubA1NweIZ8aAyjPbczNOJxwbn6gnwjhQMFS3rPLgcNG0MQuXBNYQXH/LPiSnofxmjdEqPxAmJBZulf8QdL8hWht1jxSqm/Y0wTOWZ5fPlqOGflPk3Rb89pzeWZLmfBYJcLH2f3lZK7CcI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xpDK79ob; 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="xpDK79ob" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD44FC4CEE4; Thu, 17 Apr 2025 18:51:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744915876; bh=fhC3L1YMj/cN6dZuF3uyh4CNRyhTsbQtkPkE7XIIwLw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xpDK79oblb4wQdFy4wi2l0w7I73A8YUMgnx4/WbmPOrBzoE76v9YBGNw5N0XP76ZU rLS2tHP6jgDU91CEXgCATfd3uWoz1eTB2VkYbpnL7QjeCJe3ylwxkhOsNbynVcGyjq 5rrvT5MEQ5ltwYJ4GZJ1B9XQHtTXNPVfmX3TYUVU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stefan Berger , Petr Vorel , Roberto Sassu , Mimi Zohar Subject: [PATCH 6.12 269/393] ima: limit the number of ToMToU integrity violations Date: Thu, 17 Apr 2025 19:51:18 +0200 Message-ID: <20250417175118.425496284@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250417175107.546547190@linuxfoundation.org> References: <20250417175107.546547190@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mimi Zohar commit a414016218ca97140171aa3bb926b02e1f68c2cc upstream. Each time a file in policy, that is already opened for read, is opened for write, a Time-of-Measure-Time-of-Use (ToMToU) integrity violation audit message is emitted and a violation record is added to the IMA measurement list. This occurs even if a ToMToU violation has already been recorded. Limit the number of ToMToU integrity violations per file open for read. Note: The IMA_MAY_EMIT_TOMTOU atomic flag must be set from the reader side based on policy. This may result in a per file open for read ToMToU violation. Since IMA_MUST_MEASURE is only used for violations, rename the atomic IMA_MUST_MEASURE flag to IMA_MAY_EMIT_TOMTOU. Cc: stable@vger.kernel.org # applies cleanly up to linux-6.6 Tested-by: Stefan Berger Reviewed-by: Petr Vorel Tested-by: Petr Vorel Reviewed-by: Roberto Sassu Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman --- security/integrity/ima/ima.h | 2 +- security/integrity/ima/ima_main.c | 7 ++++--- 2 files changed, 5 insertions(+), 4 deletions(-) --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -181,7 +181,7 @@ struct ima_kexec_hdr { #define IMA_UPDATE_XATTR 1 #define IMA_CHANGE_ATTR 2 #define IMA_DIGSIG 3 -#define IMA_MUST_MEASURE 4 +#define IMA_MAY_EMIT_TOMTOU 4 #define IMA_EMITTED_OPENWRITERS 5 /* IMA integrity metadata associated with an inode */ --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -129,14 +129,15 @@ static void ima_rdwr_violation_check(str if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) { if (!iint) iint = ima_iint_find(inode); + /* IMA_MEASURE is set from reader side */ - if (iint && test_bit(IMA_MUST_MEASURE, - &iint->atomic_flags)) + if (iint && test_and_clear_bit(IMA_MAY_EMIT_TOMTOU, + &iint->atomic_flags)) send_tomtou = true; } } else { if (must_measure) - set_bit(IMA_MUST_MEASURE, &iint->atomic_flags); + set_bit(IMA_MAY_EMIT_TOMTOU, &iint->atomic_flags); /* Limit number of open_writers violations */ if (inode_is_open_for_write(inode) && must_measure) {