From: Roberto Sassu <roberto.sassu@huawei.com>
To: Mimi Zohar <zohar@linux.ibm.com>, "mjg59@google.com" <mjg59@google.com>
Cc: "linux-integrity@vger.kernel.org"
<linux-integrity@vger.kernel.org>,
"linux-security-module@vger.kernel.org"
<linux-security-module@vger.kernel.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v5 06/12] evm: Ignore INTEGRITY_NOLABEL/INTEGRITY_NOXATTRS if conditions are safe
Date: Tue, 4 May 2021 13:16:03 +0000 [thread overview]
Message-ID: <1869963c94574fd1b026b304acdd308e@huawei.com> (raw)
In-Reply-To: <a2ca7317b672c63a40743268b641dd73661c3329.camel@linux.ibm.com>
> From: Mimi Zohar [mailto:zohar@linux.ibm.com]
> Sent: Monday, May 3, 2021 4:35 PM
> On Mon, 2021-05-03 at 14:15 +0000, Roberto Sassu wrote:
>
> > > > > if (evm_status != INTEGRITY_PASS)
> > > > > integrity_audit_msg(AUDIT_INTEGRITY_METADATA,
> > > > d_backing_inode(dentry),
> > > > > dentry->d_name.name,
> > > > "appraise_metadata",
> > > > > @@ -515,7 +535,8 @@ int evm_inode_setattr(struct dentry *dentry,
> > > struct
> > > > iattr *attr)
> > > > > return 0;
> > > > > evm_status = evm_verify_current_integrity(dentry);
> > > > > if ((evm_status == INTEGRITY_PASS) ||
> > > > > - (evm_status == INTEGRITY_NOXATTRS))
> > > > > + (evm_status == INTEGRITY_NOXATTRS) ||
> > > > > + (evm_ignore_error_safe(evm_status)))
> > > >
> > > > It would also remove the INTEGRITY_NOXATTRS test duplication here.
> > >
> > > Ok.
> >
> > Actually, it does not seem a duplication. Currently, INTEGRITY_NOXATTRS
> > is ignored also when the HMAC key is loaded.
>
> The existing INTEGRITY_NOXATTRS exemption is more general and includes
> the new case of when EVM HMAC is disabled. The additional exemption is
> only needed for INTEGRITY_NOLABEL, when EVM HMAC is disabled.
Unfortunately, evm_ignore_error_safe() is called by both evm_protect_xattr()
and evm_inode_setattr(). The former requires an exemption also for
INTEGRITY_NOXATTRS.
I would keep the function as it is. In the worst case, when the status is
INTEGRITY_NOXATTRS in evm_inode_setattr(), the function will not
be called.
Roberto
HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063
Managing Director: Li Peng, Li Jian, Shi Yanli
next prev parent reply other threads:[~2021-05-04 13:16 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-07 10:52 [PATCH v5 00/12] evm: Improve usability of portable signatures Roberto Sassu
2021-04-07 10:52 ` [PATCH v5 01/12] evm: Execute evm_inode_init_security() only when an HMAC key is loaded Roberto Sassu
2021-04-07 10:52 ` [PATCH v5 02/12] evm: Load EVM key in ima_load_x509() to avoid appraisal Roberto Sassu
2021-04-07 10:52 ` [PATCH v5 03/12] evm: Refuse EVM_ALLOW_METADATA_WRITES only if an HMAC key is loaded Roberto Sassu
2021-04-30 20:28 ` Mimi Zohar
2021-04-07 10:52 ` [PATCH v5 04/12] ima: Move ima_reset_appraise_flags() call to post hooks Roberto Sassu
2021-04-07 16:17 ` Casey Schaufler
2021-04-07 16:31 ` Roberto Sassu
2021-04-26 19:49 ` Mimi Zohar
2021-04-07 10:52 ` [PATCH v5 05/12] evm: Introduce evm_status_revalidate() Roberto Sassu
2021-04-07 10:52 ` [PATCH v5 06/12] evm: Ignore INTEGRITY_NOLABEL/INTEGRITY_NOXATTRS if conditions are safe Roberto Sassu
2021-05-03 0:12 ` Mimi Zohar
2021-05-03 7:55 ` Roberto Sassu
2021-05-03 12:07 ` Mimi Zohar
2021-05-03 14:15 ` Roberto Sassu
2021-05-03 14:34 ` Mimi Zohar
2021-05-04 13:16 ` Roberto Sassu [this message]
2021-05-04 13:45 ` Mimi Zohar
2021-04-07 10:52 ` [PATCH v5 07/12] evm: Allow xattr/attr operations for portable signatures Roberto Sassu
2021-05-03 0:12 ` Mimi Zohar
2021-05-04 14:28 ` Roberto Sassu
2021-05-04 14:49 ` Mimi Zohar
2021-04-07 10:52 ` [PATCH v5 08/12] evm: Pass user namespace to set/remove xattr hooks Roberto Sassu
2021-04-07 12:06 ` Christian Brauner
2021-04-07 10:52 ` [PATCH v5 09/12] evm: Allow setxattr() and setattr() for unmodified metadata Roberto Sassu
2021-04-07 12:05 ` Christian Brauner
2021-04-07 15:23 ` kernel test robot
2021-04-07 18:14 ` kernel test robot
2021-04-07 19:28 ` [RESEND][PATCH " Roberto Sassu
2021-05-03 13:00 ` [PATCH " Mimi Zohar
2021-05-03 14:48 ` Roberto Sassu
2021-05-03 15:13 ` Mimi Zohar
2021-05-03 15:30 ` Roberto Sassu
2021-05-03 15:11 ` Roberto Sassu
2021-05-03 15:26 ` Mimi Zohar
2021-05-03 15:32 ` Roberto Sassu
2021-05-03 15:48 ` Mimi Zohar
2021-04-07 10:52 ` [PATCH v5 10/12] ima: Allow imasig requirement to be satisfied by EVM portable signatures Roberto Sassu
2021-04-07 10:52 ` [PATCH v5 11/12] ima: Introduce template field evmsig and write to field sig as fallback Roberto Sassu
2021-04-07 10:52 ` [PATCH v5 12/12] ima: Don't remove security.ima if file must not be appraised Roberto Sassu
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