| Message ID | 20170710120831.9355-1-mcroce@redhat.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | stephen hemminger |
| Headers | show |
Hi Matteo, On Mon, Jul 10, 2017 at 02:08:31PM +0200, Matteo Croce wrote: > I noticed that your patch still leaves an uncovered scenario, the one where the > namespace name is "." or "..". > Calling 'ip netns del ..' will remove /var/run which is a symlink to /run on > most systems causing some daemons, eg. dbus, to fail. Oh, indeed. My patch even checks the name for 'ip netns add' only! > ip netns doesn't validate input, allowing creation and deletion of files > relatives to /var/run/netns. > This patch denies creation or deletion of namespaces with names contaning > "/" or that matches exactly "." or "..". You might want to have a look at --scissors option to git-am for a more elegant way of sending a reply with attached patch. [...] > int do_netns(int argc, char **argv) > { > netns_nsid_socket_init(); > @@ -775,6 +780,11 @@ int do_netns(int argc, char **argv) > return netns_list(0, NULL); > } > > + if (argc > 1 && invalid_name(argv[1])) { > + fprintf(stderr, "Invalid netns name \"%s\"\n", argv[1]); > + exit(-1); > + } Maybe worth noting, this assumes argv[1] will be used for the netns name which doesn't hold for 'ip netns identify' command. It doesn't matter though, since netns_identify() enforces the parameter to be either "self" or a decimal number. Yet, in future a new subcommand might be added which requires this check to be refactored. Thanks, Phil
On Mon, 10 Jul 2017 14:08:31 +0200 Matteo Croce <mcroce@redhat.com> wrote: > Hi Phil, > > I noticed that your patch still leaves an uncovered scenario, the one where the > namespace name is "." or "..". > Calling 'ip netns del ..' will remove /var/run which is a symlink to /run on > most systems causing some daemons, eg. dbus, to fail. > > ip netns doesn't validate input, allowing creation and deletion of files > relatives to /var/run/netns. > This patch denies creation or deletion of namespaces with names contaning > "/" or that matches exactly "." or "..". > --- > ip/ipnetns.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > The patch itself is good, but the commit message needs fixing. Please rewrite it to describe the problem, and add signed-off-by
diff --git a/ip/ipnetns.c b/ip/ipnetns.c index 0b0378a..4254994 100644 --- a/ip/ipnetns.c +++ b/ip/ipnetns.c @@ -766,6 +766,11 @@ static int netns_monitor(int argc, char **argv) return 0; } +static int invalid_name(const char *name) +{ + return strchr(name, '/') || !strcmp(name, ".") || !strcmp(name, ".."); +} + int do_netns(int argc, char **argv) { netns_nsid_socket_init(); @@ -775,6 +780,11 @@ int do_netns(int argc, char **argv) return netns_list(0, NULL); } + if (argc > 1 && invalid_name(argv[1])) { + fprintf(stderr, "Invalid netns name \"%s\"\n", argv[1]); + exit(-1); + } + if ((matches(*argv, "list") == 0) || (matches(*argv, "show") == 0) || (matches(*argv, "lst") == 0)) { netns_map_init();