| Message ID | 20160721164014.17534-9-ebiederm@xmission.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Quoting Eric W. Biederman (ebiederm@xmission.com): > Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Serge Hallyn <serge@hallyn.com> > --- > include/linux/user_namespace.h | 1 + > kernel/user_namespace.c | 1 + > net/core/net_namespace.c | 15 +++++++++++++++ > 3 files changed, 17 insertions(+) > > diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h > index 1a3a9cb93277..f86afa536baf 100644 > --- a/include/linux/user_namespace.h > +++ b/include/linux/user_namespace.h > @@ -27,6 +27,7 @@ enum ucounts { > UCOUNT_PID_NAMESPACES, > UCOUNT_UTS_NAMESPACES, > UCOUNT_IPC_NAMESPACES, > + UCOUNT_NET_NAMESPACES, > UCOUNT_CGROUP_NAMESPACES, > UCOUNT_COUNTS, > }; > diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c > index 1cf074cb47e2..e326ca722ae0 100644 > --- a/kernel/user_namespace.c > +++ b/kernel/user_namespace.c > @@ -80,6 +80,7 @@ static struct ctl_table userns_table[] = { > UCOUNT_ENTRY("max_pid_namespaces"), > UCOUNT_ENTRY("max_uts_namespaces"), > UCOUNT_ENTRY("max_ipc_namespaces"), > + UCOUNT_ENTRY("max_net_namespaces"), > UCOUNT_ENTRY("max_cgroup_namespaces"), > { } > }; > diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c > index 2c2eb1b629b1..a489f192d619 100644 > --- a/net/core/net_namespace.c > +++ b/net/core/net_namespace.c > @@ -266,6 +266,16 @@ struct net *get_net_ns_by_id(struct net *net, int id) > return peer; > } > > +static bool inc_net_namespaces(struct user_namespace *ns) > +{ > + return inc_ucount(ns, UCOUNT_NET_NAMESPACES); > +} > + > +static void dec_net_namespaces(struct user_namespace *ns) > +{ > + dec_ucount(ns, UCOUNT_NET_NAMESPACES); > +} > + > /* > * setup_net runs the initializers for the network namespace object. > */ > @@ -276,6 +286,9 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) > int error = 0; > LIST_HEAD(net_exit_list); > > + if (!inc_net_namespaces(user_ns)) > + return -ENFILE; > + > atomic_set(&net->count, 1); > atomic_set(&net->passive, 1); > net->dev_base_seq = 1; > @@ -372,6 +385,7 @@ struct net *copy_net_ns(unsigned long flags, > } > mutex_unlock(&net_mutex); > if (rv < 0) { > + dec_net_namespaces(user_ns); > put_user_ns(user_ns); > net_drop_ns(net); > return ERR_PTR(rv); > @@ -444,6 +458,7 @@ static void cleanup_net(struct work_struct *work) > /* Finally it is safe to free my network namespace structure */ > list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) { > list_del_init(&net->exit_list); > + dec_net_namespaces(net->user_ns); > put_user_ns(net->user_ns); > net_drop_ns(net); > } > -- > 2.8.3 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jul 21, 2016 at 9:40 AM, Eric W. Biederman <ebiederm@xmission.com> wrote: > Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> > --- > include/linux/user_namespace.h | 1 + > kernel/user_namespace.c | 1 + > net/core/net_namespace.c | 15 +++++++++++++++ > 3 files changed, 17 insertions(+) > > diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h > index 1a3a9cb93277..f86afa536baf 100644 > --- a/include/linux/user_namespace.h > +++ b/include/linux/user_namespace.h > @@ -27,6 +27,7 @@ enum ucounts { > UCOUNT_PID_NAMESPACES, > UCOUNT_UTS_NAMESPACES, > UCOUNT_IPC_NAMESPACES, > + UCOUNT_NET_NAMESPACES, > UCOUNT_CGROUP_NAMESPACES, > UCOUNT_COUNTS, > }; > diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c > index 1cf074cb47e2..e326ca722ae0 100644 > --- a/kernel/user_namespace.c > +++ b/kernel/user_namespace.c > @@ -80,6 +80,7 @@ static struct ctl_table userns_table[] = { > UCOUNT_ENTRY("max_pid_namespaces"), > UCOUNT_ENTRY("max_uts_namespaces"), > UCOUNT_ENTRY("max_ipc_namespaces"), > + UCOUNT_ENTRY("max_net_namespaces"), > UCOUNT_ENTRY("max_cgroup_namespaces"), > { } > }; > diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c > index 2c2eb1b629b1..a489f192d619 100644 > --- a/net/core/net_namespace.c > +++ b/net/core/net_namespace.c > @@ -266,6 +266,16 @@ struct net *get_net_ns_by_id(struct net *net, int id) > return peer; > } > > +static bool inc_net_namespaces(struct user_namespace *ns) > +{ > + return inc_ucount(ns, UCOUNT_NET_NAMESPACES); > +} > + > +static void dec_net_namespaces(struct user_namespace *ns) > +{ > + dec_ucount(ns, UCOUNT_NET_NAMESPACES); > +} > + > /* > * setup_net runs the initializers for the network namespace object. > */ > @@ -276,6 +286,9 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) > int error = 0; > LIST_HEAD(net_exit_list); > > + if (!inc_net_namespaces(user_ns)) > + return -ENFILE; I think you need to move this check after initilizing net->passive. When setup_net returns an error, net_drop_ns is called: void net_drop_ns(void *p) { struct net *ns = p; if (ns && atomic_dec_and_test(&ns->passive)) net_free(ns); } Actually, I think it would be better to make this check before net_alloc(). > + > atomic_set(&net->count, 1); > atomic_set(&net->passive, 1); > net->dev_base_seq = 1; > @@ -372,6 +385,7 @@ struct net *copy_net_ns(unsigned long flags, > } > mutex_unlock(&net_mutex); > if (rv < 0) { > + dec_net_namespaces(user_ns); > put_user_ns(user_ns); > net_drop_ns(net); > return ERR_PTR(rv); > @@ -444,6 +458,7 @@ static void cleanup_net(struct work_struct *work) > /* Finally it is safe to free my network namespace structure */ > list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) { > list_del_init(&net->exit_list); > + dec_net_namespaces(net->user_ns); > put_user_ns(net->user_ns); > net_drop_ns(net); > } > -- > 2.8.3 > > _______________________________________________ > Containers mailing list > Containers@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/containers -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Andrei Vagin <avagin@gmail.com> writes: > On Thu, Jul 21, 2016 at 9:40 AM, Eric W. Biederman <ebiederm@xmission.com> wrote: >> index 2c2eb1b629b1..a489f192d619 100644 >> --- a/net/core/net_namespace.c >> +++ b/net/core/net_namespace.c >> @@ -266,6 +266,16 @@ struct net *get_net_ns_by_id(struct net *net, int id) >> return peer; >> } >> >> +static bool inc_net_namespaces(struct user_namespace *ns) >> +{ >> + return inc_ucount(ns, UCOUNT_NET_NAMESPACES); >> +} >> + >> +static void dec_net_namespaces(struct user_namespace *ns) >> +{ >> + dec_ucount(ns, UCOUNT_NET_NAMESPACES); >> +} >> + >> /* >> * setup_net runs the initializers for the network namespace object. >> */ >> @@ -276,6 +286,9 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) >> int error = 0; >> LIST_HEAD(net_exit_list); >> >> + if (!inc_net_namespaces(user_ns)) >> + return -ENFILE; > > I think you need to move this check after initilizing net->passive. > When setup_net returns an error, net_drop_ns is called: > Good point. Ouch! > void net_drop_ns(void *p) > { > struct net *ns = p; > if (ns && atomic_dec_and_test(&ns->passive)) > net_free(ns); > } > > Actually, I think it would be better to make this check before > net_alloc(). You are probably right. I seem to be trying to be entirely too clever putting that in setup_net so I can cover the initial network namespace. Which really does not need to be counted. As clearly I also goofed up the decrement on error case as well. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index 1a3a9cb93277..f86afa536baf 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -27,6 +27,7 @@ enum ucounts { UCOUNT_PID_NAMESPACES, UCOUNT_UTS_NAMESPACES, UCOUNT_IPC_NAMESPACES, + UCOUNT_NET_NAMESPACES, UCOUNT_CGROUP_NAMESPACES, UCOUNT_COUNTS, }; diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 1cf074cb47e2..e326ca722ae0 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -80,6 +80,7 @@ static struct ctl_table userns_table[] = { UCOUNT_ENTRY("max_pid_namespaces"), UCOUNT_ENTRY("max_uts_namespaces"), UCOUNT_ENTRY("max_ipc_namespaces"), + UCOUNT_ENTRY("max_net_namespaces"), UCOUNT_ENTRY("max_cgroup_namespaces"), { } }; diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 2c2eb1b629b1..a489f192d619 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -266,6 +266,16 @@ struct net *get_net_ns_by_id(struct net *net, int id) return peer; } +static bool inc_net_namespaces(struct user_namespace *ns) +{ + return inc_ucount(ns, UCOUNT_NET_NAMESPACES); +} + +static void dec_net_namespaces(struct user_namespace *ns) +{ + dec_ucount(ns, UCOUNT_NET_NAMESPACES); +} + /* * setup_net runs the initializers for the network namespace object. */ @@ -276,6 +286,9 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) int error = 0; LIST_HEAD(net_exit_list); + if (!inc_net_namespaces(user_ns)) + return -ENFILE; + atomic_set(&net->count, 1); atomic_set(&net->passive, 1); net->dev_base_seq = 1; @@ -372,6 +385,7 @@ struct net *copy_net_ns(unsigned long flags, } mutex_unlock(&net_mutex); if (rv < 0) { + dec_net_namespaces(user_ns); put_user_ns(user_ns); net_drop_ns(net); return ERR_PTR(rv); @@ -444,6 +458,7 @@ static void cleanup_net(struct work_struct *work) /* Finally it is safe to free my network namespace structure */ list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) { list_del_init(&net->exit_list); + dec_net_namespaces(net->user_ns); put_user_ns(net->user_ns); net_drop_ns(net); }
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> --- include/linux/user_namespace.h | 1 + kernel/user_namespace.c | 1 + net/core/net_namespace.c | 15 +++++++++++++++ 3 files changed, 17 insertions(+)