[CRIU] [PATCH] net: don't call netns_entry__free_unpacked for uninitialized pointer

[Andrew Vagin]

On Tue, Jun 09, 2015 at 05:42:00AM -0600, Tycho Andersen wrote:
> On Tue, Jun 09, 2015 at 02:24:48PM +0300, Andrey Vagin wrote:
> > If the netns image is absent, the NetnsEntry entry will not be initialized.
> > 
> > Currently restore from old images crashes:
> > 
> > Core was generated by `criu swrk 3'.
> > Program terminated with signal SIGSEGV, Segmentation fault.
> > $0  0x0000000000427d80 in netns_entry.free_unpacked ()
> > (gdb) bt
> > $0  0x0000000000427d80 in netns_entry.free_unpacked ()
> > $1  0x0000000000436d07 in prepare_net_ns ()
> > $2  0x0000000000457c78 in prepare_namespace ()
> > $3  0x0000000000432917 in restore_task_with_children ()
> > $4  0x00007fc86acfccfd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111
> > 
> > Cc: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
> > Signed-off-by: Andrey Vagin <avagin at openvz.org>
> > ---
> >  cr-service.c | 1 +
> >  crtools.c    | 2 +-
> >  net.c        | 5 +++--
> >  3 files changed, 5 insertions(+), 3 deletions(-)
> > 
> > diff --git a/cr-service.c b/cr-service.c
> > index 60a7289..98601f8 100644
> > --- a/cr-service.c
> > +++ b/cr-service.c
> > @@ -269,6 +269,7 @@ static int setup_opts_from_req(int sk, CriuOpts *req)
> >  		opts.output = req->log_file;
> >  	} else
> >  		opts.output = DEFAULT_LOG_FILENAME;
> > +	opts.output = "/tmp/restore.log";
> >  
> >  	log_set_loglevel(req->log_level);
> >  	if (log_init(opts.output) == -1) {
> > diff --git a/crtools.c b/crtools.c
> > index f83db27..61e03c9 100644
> > --- a/crtools.c
> > +++ b/crtools.c
> > @@ -288,7 +288,7 @@ int main(int argc, char *argv[], char *envp[])
> >  			work_dir = optarg;
> >  			break;
> >  		case 'o':
> > -			opts.output = optarg;
> > +			opts.output = "/tmp/restore.log";//optarg;
> 
> I guess this and the hunk above are debugging?

It's a big improvement. Now you will always know where restore.log is saved ;).

I've sent a new version. Thank you for the comment.

> 
> Tycho
> 
> >  			break;
> >  		case 'n':
> >  			if (parse_ns_string(optarg))
> > diff --git a/net.c b/net.c
> > index e7354a4..082ccb6 100644
> > --- a/net.c
> > +++ b/net.c
> > @@ -728,12 +728,13 @@ int dump_net_ns(int ns_id)
> >  int prepare_net_ns(int pid)
> >  {
> >  	int ret;
> > -	NetnsEntry *netns;
> > +	NetnsEntry *netns = NULL;
> >  
> >  	ret = restore_netns_conf(pid, &netns);
> >  	if (!ret)
> >  		ret = restore_links(pid, &netns);
> > -	netns_entry__free_unpacked(netns, NULL);
> > +	if (netns)
> > +		netns_entry__free_unpacked(netns, NULL);
> >  
> >  	if (!ret)
> >  		ret = restore_ifaddr(pid);
> > -- 
> > 2.1.0
> > 
> > _______________________________________________
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> > CRIU at openvz.org
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