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 81F851D8DF6; Thu, 17 Apr 2025 18:09:30 +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=1744913370; cv=none; b=L7JiKuaSy05SV7JsQuQAFq7gWMnywjHmF6mv8aTd56D/4oG2MIBhoKMQ+ozpXxfOrfuDvBhM118AfCxE0iy7hdirvYLzot6WpO4Vw3OWhlL5tmq7u432eppSi4upDeQf0da5AWeuEL735Z52ax2R/YyRyDDKFzlgnrYOXB7NYTc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744913370; c=relaxed/simple; bh=fxRTxWfokBHg7kvj0yGyKgWr4SY20Ix0A/EI6p5KPyo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pZBQDFe1EC8pf6wit7pUpQFC2T7szpRAAieoXia05+3umGjbQ9VNm/2qc5Wsn20h/ZEov9oes6gclt+Khj5q/UoatK5VC9SzcH9/IteerK3yinB7PsulndOmRghrzf3HTIDqXxUNg0O5NwyIvmJxCrtbytdYKL0+tfn1/4049v8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=kLulRIZC; 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="kLulRIZC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 846DAC4CEE4; Thu, 17 Apr 2025 18:09:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744913370; bh=fxRTxWfokBHg7kvj0yGyKgWr4SY20Ix0A/EI6p5KPyo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kLulRIZCo+2YfTXq31slvotNad9OSG5fJNkgy+8lO9M1/pg8p7O2P354B9BxOiV6t fXdNn2B5u3n8xfdYRTl0sPB8jZHCiYIHFdRuRkibwLFh0WMmywN6fi+/w0s+H8LN/3 DseAWATKM8lJUAgBRimvP3A0LarIO5pEvb4L9leo= 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 6.14 316/449] ima: limit the number of ToMToU integrity violations Date: Thu, 17 Apr 2025 19:50:04 +0200 Message-ID: <20250417175130.832876448@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250417175117.964400335@linuxfoundation.org> References: <20250417175117.964400335@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 6.14-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) {