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Date: Thu, 05 Mar 2015 00:10:35 +0300
From: Michael Tokarev <mjt@tls.msk.ru>
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Subject: [Qemu-devel] 9pfs-local: open2() deletes existing data?
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To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: qemu-devel <qemu-devel@nongnu.org>

I was looking at various interesting functions in hw/9pfs/virtio-9p-local.c
and noticed local_open2() which basically tries to open a file in a
filesystem, and if that is successful, it tries to set file credentials
using a configured mechanism, and if that fails, it deletes the file.

Now I wonder what happens if we tried to open an existing file but was
not able to set credentials for whatever reason -- eg, because the
underlying filesystem does not support xattrs, or whatever.  It looks
to me that we will remove the user file!

If that's the case, it looks like it is a very serious bug...

Thanks,

/mjt