diff options
| author | Daniel P. Berrange <berrange@redhat.com> | 2013-03-19 11:20:20 +0000 |
|---|---|---|
| committer | Anthony Liguori <aliguori@us.ibm.com> | 2013-04-15 14:29:20 -0500 |
| commit | e6b636779b51c97e67694be740ee972c52460c59 (patch) | |
| tree | 132813125593e7128b06d88fc88f27530599a430 /qemu-nbd.texi | |
| parent | 0ca5aa4f4c4a8bcc73988dd52a536241d35e5223 (diff) | |
Add -f FMT / --format FMT arg to qemu-nbd
Currently the qemu-nbd program will auto-detect the format of
any disk it is given. This behaviour is known to be insecure.
For example, if qemu-nbd initially exposes a 'raw' file to an
unprivileged app, and that app runs
'qemu-img create -f qcow2 -o backing_file=/etc/shadow /dev/nbd0'
then the next time the app is started, the qemu-nbd will now
detect it as a 'qcow2' file and expose /etc/shadow to the
unprivileged app.
The only way to avoid this is to explicitly tell qemu-nbd what
disk format to use on the command line, completely disabling
auto-detection. This patch adds a '-f' / '--format' arg for
this purpose, mirroring what is already available via qemu-img
and qemu commands.
qemu-nbd --format raw -p 9000 evil.img
will now always use raw, regardless of what format 'evil.img'
looks like it contains
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
[Use errx, not err. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'qemu-nbd.texi')
| -rw-r--r-- | qemu-nbd.texi | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/qemu-nbd.texi b/qemu-nbd.texi index 5f3f3e3276..6055ec693b 100644 --- a/qemu-nbd.texi +++ b/qemu-nbd.texi @@ -45,6 +45,8 @@ Export QEMU disk image using NBD protocol. disconnect the specified device @item -e, --shared=@var{num} device can be shared by @var{num} clients (default @samp{1}) +@item -f, --format=@var{fmt} + force block driver for format @var{fmt} instead of auto-detecting @item -t, --persistent don't exit on the last connection @item -v, --verbose |