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From: Al Viro <viro@ZenIV.linux.org.uk>
To: Ilya Matveychikov <matvejchikov@gmail.com>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH] ksys_mount: check for permissions before resource allocation
Date: Tue, 5 Jun 2018 12:26:41 +0100	[thread overview]
Message-ID: <20180605112641.GN30522@ZenIV.linux.org.uk> (raw)
In-Reply-To: <BD48252B-65D7-4238-BDA2-71BAC1CEA855@gmail.com>

On Tue, Jun 05, 2018 at 10:59:51AM +0400, Ilya Matveychikov wrote:
> Just CC’ed to some of maintainers.
> 
> $ perl scripts/get_maintainer.pl fs/0001-ksys_mount-check-for-permissions-before-resource-all.patch
> Alexander Viro <viro@zeniv.linux.org.uk> (maintainer:FILESYSTEMS (VFS and infrastructure))
> linux-fsdevel@vger.kernel.org (open list:FILESYSTEMS (VFS and infrastructure))
> linux-kernel@vger.kernel.org (open list)
> 
> > On Jun 5, 2018, at 6:00 AM, Ilya Matveychikov <matvejchikov@gmail.com> wrote:
> > 
> > Early check for mount permissions prevents possible allocation of 3
> > pages from kmalloc() pool by unpriveledged user which can be used for
> > spraying the kernel heap.

I'm sorry, but there are arseloads of unpriveleged syscalls that do the same,
starting with read() from procfs files.  So what the hell does it buy?

  reply	other threads:[~2018-06-05 11:26 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <D2317950-0DB0-4311-ADB1-FF677B676E04@gmail.com>
2018-06-05  6:59 ` [PATCH] ksys_mount: check for permissions before resource allocation Ilya Matveychikov
2018-06-05 11:26   ` Al Viro [this message]
2018-06-05 11:35     ` Ilya Matveychikov
2018-06-05 11:53       ` Al Viro
2018-06-05 12:07         ` Ilya Matveychikov
2018-06-05 12:28           ` David Sterba
2018-06-05 12:42             ` Ilya Matveychikov
2018-06-05 12:34           ` Al Viro
2018-06-05 19:56   ` Eric W. Biederman
2018-06-06  9:32     ` Ilya Matveychikov
2018-06-06 14:22       ` Eric W. Biederman
2018-06-06 15:26         ` Ilya Matveychikov

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