Re: [Libguestfs] [PATCH] Fix error launching libguestfs when euid != uid

Improved patch. This copies your code to set real UID and GID before the exec. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://et.redhat.com/~rjones/virt-top 0001-Fix-error-launching-libguestfs-when-euid-uid.patch From d00e2fb8c2e26e0a48954472b52bd0be877e9ce6 Mon Sep 17 00:00:00 2001 From: Richard W.M. Jones<rjones(a)redhat.com> Date: Mon, 20 Sep 2010 14:02:06 +0100 Subject: [PATCH] Fix error launching libguestfs when euid != uid. When writing to a RHEV target, virt-v2v launches the libguestfs appliance with euid:egid = 36:36, which is required to write to an NFS target using root_squash. Since we changed to using a cached appliance, this causes an error on start up, as the cached files are owned by root, but the cache directory is owned by 36:36. The reason is that bash resets euid to uid and egid to gid so when febootstrap-supermin-helper is executed, it runs as root:root. The cache directory was created by libguestfs directly so it has the correct ownership. This patch fixes the issue by using explicit fork/exec instead of system (ie. not going via a shell) and by setting the real UID and GID to the effective UID and GID before execing. --- src/appliance.c | 133 ++++++++++++++++++++++++++++++++++++++++++++---------- 1 files changed, 108 insertions(+), 25 deletions(-)