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From: Mimi Zohar <zohar@linux.ibm.com>
To: Roberto Sassu <roberto.sassu@huawei.com>, mjg59@google.com
Cc: linux-integrity@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 04/11] evm: Introduce evm_status_revalidate()
Date: Tue, 11 May 2021 09:42:08 -0400	[thread overview]
Message-ID: <a0657cec664efcedb3d2501ac10e7365fd196e77.camel@linux.ibm.com> (raw)
In-Reply-To: <20210505112935.1410679-5-roberto.sassu@huawei.com>

On Wed, 2021-05-05 at 13:29 +0200, Roberto Sassu wrote:
> When EVM_ALLOW_METADATA_WRITES is set, EVM allows any operation on
> metadata. Its main purpose is to allow users to freely set metadata when it
> is protected by a portable signature, until an HMAC key is loaded.
> 
> However, callers of evm_verifyxattr() are not notified about metadata
> changes and continue to rely on the last status returned by the function.
> For example IMA, since it caches the appraisal result, will not call again
> evm_verifyxattr() until the appraisal flags are cleared, and will grant
> access to the file even if there was a metadata operation that made the
> portable signature invalid.
> 
> This patch introduces evm_status_revalidate(), which callers of
> evm_verifyxattr() can use in their xattr hooks to determine whether
> re-validation is necessary and to do the proper actions. IMA calls it in
> its xattr hooks to reset the appraisal flags, so that the EVM status is
> re-evaluated after a metadata operation.
> 
> Lastly, this patch also adds a call to evm_reset_status() in
> evm_inode_post_setattr() to invalidate the cached EVM status after a
> setattr operation.
> 
> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>

I'm really  sorry for the patch churn, but could you rename
evm_status_revalidate() to evm_revalidate_status().

Otherwise,

Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>

thanks,

Mimi


  reply	other threads:[~2021-05-11 13:42 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-05 11:29 [PATCH v6 00/11] evm: Improve usability of portable signatures Roberto Sassu
2021-05-05 11:29 ` [PATCH v6 01/11] evm: Execute evm_inode_init_security() only when an HMAC key is loaded Roberto Sassu
2021-05-05 11:29 ` [PATCH v6 02/11] evm: Load EVM key in ima_load_x509() to avoid appraisal Roberto Sassu
2021-05-05 11:29 ` [PATCH v6 03/11] evm: Refuse EVM_ALLOW_METADATA_WRITES only if an HMAC key is loaded Roberto Sassu
2021-05-11 13:41   ` Mimi Zohar
2021-05-11 14:12     ` Roberto Sassu
2021-05-11 19:53       ` Mimi Zohar
2021-05-05 11:29 ` [PATCH v6 04/11] evm: Introduce evm_status_revalidate() Roberto Sassu
2021-05-11 13:42   ` Mimi Zohar [this message]
2021-05-05 11:33 ` [PATCH v6 05/11] evm: Introduce evm_hmac_disabled() to safely ignore verification errors Roberto Sassu
2021-05-07 13:31   ` [RESEND][PATCH " Roberto Sassu
2021-05-11 13:42     ` Mimi Zohar
2021-05-05 11:33 ` [PATCH v6 06/11] evm: Allow xattr/attr operations for portable signatures Roberto Sassu
2021-05-05 11:33 ` [PATCH v6 07/11] evm: Pass user namespace to set/remove xattr hooks Roberto Sassu
2021-05-05 11:33 ` [PATCH v6 08/11] evm: Allow setxattr() and setattr() for unmodified metadata Roberto Sassu
2021-05-11 14:11   ` Mimi Zohar
2021-05-11 14:21     ` Roberto Sassu
2021-05-11 14:40       ` Mimi Zohar
2021-05-11 14:54         ` Roberto Sassu
2021-05-11 20:00           ` Mimi Zohar
2021-05-05 11:33 ` [PATCH v6 09/11] ima: Allow imasig requirement to be satisfied by EVM portable signatures Roberto Sassu
2021-05-05 11:33 ` [PATCH v6 10/11] ima: Introduce template field evmsig and write to field sig as fallback Roberto Sassu
2021-05-11 22:12   ` Mimi Zohar
2021-05-12 10:55     ` Roberto Sassu
2021-05-05 11:33 ` [PATCH v6 11/11] ima: Don't remove security.ima if file must not be appraised Roberto Sassu

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