From: Connor Kuehl <ckuehl@redhat.com>
To: Greg Kurz <groug@kaod.org>, qemu-devel@nongnu.org
Cc: virtio-fs@redhat.com
Subject: Re: [Virtio-fs] [PATCH 3/3] virtiofsd: Don't allow empty filenames
Date: Fri, 12 Mar 2021 09:13:54 -0600 [thread overview]
Message-ID: <c56bcaab-4a2d-219b-5d83-49dfd6fa1483@redhat.com> (raw)
In-Reply-To: <20210312141003.819108-4-groug@kaod.org>
On 3/12/21 8:10 AM, Greg Kurz wrote:
> POSIX.1-2017 clearly stipulates that empty filenames aren't
> allowed ([1] and [2]). Since virtiofsd is supposed to mirror
> the host file system hierarchy and the host can be assumed to
> be linux, we don't really expect clients to pass requests with
> an empty path in it. If they do so anyway, this would eventually
> cause an error when trying to create/lookup the actual inode
> on the underlying POSIX filesystem. But this could still confuse
> some code that wouldn't be ready to cope with this.
>
> Filter out empty names coming from the client at the top level,
> so that the rest doesn't have to care about it. This is done
> everywhere we already call is_safe_path_component(), but
> in a separate helper since the usual error for empty path
> names is ENOENT instead of EINVAL.
>
> [1] https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_170
> [2] https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13
>
> Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Connor Kuehl <ckuehl@redhat.com>
next prev parent reply other threads:[~2021-03-12 15:24 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-12 14:10 [PATCH 0/3] virtiofsd: Deal with empty filenames Greg Kurz
2021-03-12 14:10 ` [PATCH 1/3] virtiofsd: Don't allow empty paths in lookup_name() Greg Kurz
2021-03-12 15:13 ` [Virtio-fs] " Connor Kuehl
2021-03-12 15:49 ` Greg Kurz
2021-03-14 23:38 ` Vivek Goyal
2021-03-12 14:10 ` [PATCH 2/3] virtiofsd: Convert some functions to return bool Greg Kurz
2021-03-12 15:13 ` [Virtio-fs] " Connor Kuehl
2021-03-14 23:36 ` Vivek Goyal
2021-03-12 14:10 ` [PATCH 3/3] virtiofsd: Don't allow empty filenames Greg Kurz
2021-03-12 15:13 ` Connor Kuehl [this message]
2021-03-14 23:36 ` [Virtio-fs] " Vivek Goyal
2021-03-15 10:06 ` Greg Kurz
2021-03-15 15:18 ` Dr. David Alan Gilbert
2021-03-15 17:37 ` Greg Kurz
2021-03-15 17:55 ` Vivek Goyal
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