Re: [PATCH] lxc: Fix segfault when lxc.network does not start with 'type'

On 2/6/20 3:12 AM, Julio Faracco wrote: > To configure network settings using config file, legacy LXC settings > require starting them with 'lxc.network.type' entry. If someone > accidentally starts with 'lxc.network.name', libvirt will crash with > segfault. This patch checks if this case is happening. > > Sample invalid settings: > lxc.network.link = eth0 > lxc.network.type = phys > lxc.network.name = eth1 > lxc.network.ipv4 = 192.168.122.2/24 > lxc.network.ipv4.gateway = 192.168.122.1 > > Now, libvirt only see error without segmentation fault. > > Signed-off-by: Julio Faracco <jcfaracco(a)gmail.com&gt; > --- > src/lxc/lxc_native.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/src/lxc/lxc_native.c b/src/lxc/lxc_native.c > index 59f3dd4fee..5462b74b85 100644 > --- a/src/lxc/lxc_native.c > +++ b/src/lxc/lxc_native.c > @@ -717,7 +717,11 @@ lxcNetworkGetParseDataByIndexLegacy(lxcNetworkParseDataArray *networks, > } > > /* Return last element added like a stack. */ > - return networks->parseData[ndata - 1]; > + if (networks->ndata > 0) > + return networks->parseData[ndata - 1]; This doesn't feel right. The same variable should be used in both lines. I mean either go with: if (ndata > 0) return networks->parseData[ndata - 1]; or: if (networks->ndata > 0) return networks->parseData[networks->ndata - 1]; The first one looks better to me. I can fix it before pushing, if you agree. Michal