From: Christoph Hellwig <hch@lst.de>
To: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Jens Axboe <axboe@kernel.dk>, Christoph Hellwig <hch@lst.de>,
Kees Cook <keescook@chromium.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: Does uaccess_kernel() work for detecting kernel thread?
Date: Wed, 23 Dec 2020 08:53:07 +0100 [thread overview]
Message-ID: <20201223075307.GA4185@lst.de> (raw)
In-Reply-To: <0bcc0c63-31a3-26fd-bccb-b28af0375c34@i-love.sakura.ne.jp>
On Tue, Dec 22, 2020 at 11:39:08PM +0900, Tetsuo Handa wrote:
> For example, if uaccess_kernel() is "false" due to CONFIG_SET_FS=n,
> isn't sg_check_file_access() failing to detect kernel context?
sg_check_file_access does exactly the right thing - fail for all kernel
threads as those can't support the magic it does.
> For another example, if uaccess_kernel() is "false" due to CONFIG_SET_FS=n,
> isn't TOMOYO unexpectedly checking permissions for socket operations?
Can someone explain WTF TOMOYO is even doing there? A security module
has absolutely no business checking what context it is called from, but
must check the process credentials instead.
next prev parent reply other threads:[~2020-12-23 7:53 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-22 14:39 Does uaccess_kernel() work for detecting kernel thread? Tetsuo Handa
2020-12-22 17:33 ` Eric W. Biederman
2021-01-05 7:57 ` Christoph Hellwig
2020-12-23 7:53 ` Christoph Hellwig [this message]
2020-12-23 10:11 ` Tetsuo Handa
2021-01-05 7:59 ` Christoph Hellwig
2021-01-05 10:11 ` Tetsuo Handa
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