From: zohar@linux.vnet.ibm.com (Mimi Zohar)
To: linux-security-module@vger.kernel.org
Subject: [PATCH 3/3] ima: use fs method to read integrity data
Date: Fri, 15 Sep 2017 11:21:21 -0400 [thread overview]
Message-ID: <1505488881.4200.96.camel@linux.vnet.ibm.com> (raw)
In-Reply-To: <20170915144903.GA3854@infradead.org>
On Fri, 2017-09-15 at 07:49 -0700, Christoph Hellwig wrote:
> On Thu, Sep 14, 2017 at 10:50:27PM -0700, Linus Torvalds wrote:
> > This is still wrong.
> >
> > (a) there is no explanation for why we need that exclusive lock in the
> > first place
> >
> > Why should a read need exclusive access? You'd think shared is sufficient.
> > But regardless, it needs *explanation*.
>
> Shared is sufficient, and nothing in the patch (except for the
> description) actually requires an exclusive lock. It just happens that
> ima holds it exclusive for other internal reasons.
Although reading the file to calculate the file hash doesn't require
taking the lock exclusively, in either "fix" mode or called from
__fput, immediately after calculating the file hash, the file hash is
written out as an xattr. ?Writing the xattr requires taking the lock
exclusively.
Mimi
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next prev parent reply other threads:[~2017-09-15 15:21 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-15 4:58 [PATCH 0/3] ima: only call integrity_kernel_read to calc file hash Mimi Zohar
2017-09-15 4:58 ` [PATCH 1/3] vfs: constify path argument to kernel_read_file_from_path Mimi Zohar
2017-09-15 18:37 ` Linus Torvalds
2017-09-15 4:58 ` [PATCH 2/3] integrity: replace call to integrity_read_file with kernel version Mimi Zohar
2017-09-15 4:58 ` [PATCH 3/3] ima: use fs method to read integrity data Mimi Zohar
[not found] ` <CA+55aFwVujvsdaq09O216u-uBbBbo5i_1d6aw3ksottR_uiJ6w@mail.gmail.com>
2017-09-15 9:04 ` Mimi Zohar
2017-09-15 9:09 ` Mimi Zohar
2017-09-15 18:05 ` Linus Torvalds
2017-09-15 14:49 ` Christoph Hellwig
2017-09-15 15:21 ` Mimi Zohar [this message]
2017-09-15 20:25 ` [PATCH 3/3] ima: use fs method to read integrity data (updated patch description) Mimi Zohar
2017-09-16 18:20 ` Linus Torvalds
2017-09-17 5:47 ` Mimi Zohar
2017-09-17 15:17 ` Christoph Hellwig
2017-09-17 15:28 ` Linus Torvalds
2017-09-17 15:37 ` Christoph Hellwig
2017-09-17 16:15 ` Mimi Zohar
2017-09-17 16:34 ` Linus Torvalds
2017-09-17 16:38 ` Al Viro
2017-09-18 9:19 ` Steven Whitehouse
2017-09-18 10:13 ` Jan Kara
2017-09-18 14:55 ` Mimi Zohar
2017-09-24 22:55 ` Mimi Zohar
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