| Message ID | 20160721164014.17534-6-ebiederm@xmission.com |
|---|---|
| State | Deferred, archived |
| Delegated to: | David Miller |
| 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 + > kernel/utsname.c | 31 ++++++++++++++++++++++++++----- > 3 files changed, 28 insertions(+), 5 deletions(-) > > diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h > index 47733637741a..bed2506081fe 100644 > --- a/include/linux/user_namespace.h > +++ b/include/linux/user_namespace.h > @@ -25,6 +25,7 @@ struct uid_gid_map { /* 64 bytes -- 1 cache line */ > enum ucounts { > UCOUNT_USER_NAMESPACES, > UCOUNT_PID_NAMESPACES, > + UCOUNT_UTS_NAMESPACES, > UCOUNT_COUNTS, > }; > > diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c > index 02a03ead7afc..6b205c24e888 100644 > --- a/kernel/user_namespace.c > +++ b/kernel/user_namespace.c > @@ -78,6 +78,7 @@ static int count_max = COUNT_MAX; > static struct ctl_table userns_table[] = { > UCOUNT_ENTRY("max_user_namespaces"), > UCOUNT_ENTRY("max_pid_namespaces"), > + UCOUNT_ENTRY("max_uts_namespaces"), > { } > }; > #endif /* CONFIG_SYSCTL */ > diff --git a/kernel/utsname.c b/kernel/utsname.c > index 831ea7108232..4f13c0419d64 100644 > --- a/kernel/utsname.c > +++ b/kernel/utsname.c > @@ -17,6 +17,16 @@ > #include <linux/user_namespace.h> > #include <linux/proc_ns.h> > > +static bool inc_uts_namespaces(struct user_namespace *ns) > +{ > + return inc_ucount(ns, UCOUNT_UTS_NAMESPACES); > +} > + > +static void dec_uts_namespaces(struct user_namespace *ns) > +{ > + dec_ucount(ns, UCOUNT_UTS_NAMESPACES); > +} > + > static struct uts_namespace *create_uts_ns(void) > { > struct uts_namespace *uts_ns; > @@ -38,15 +48,18 @@ static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns, > struct uts_namespace *ns; > int err; > > + err = -ENFILE; > + if (!inc_uts_namespaces(user_ns)) > + goto fail; > + > + err = -ENOMEM; > ns = create_uts_ns(); > if (!ns) > - return ERR_PTR(-ENOMEM); > + goto fail_dec; > > err = ns_alloc_inum(&ns->ns); > - if (err) { > - kfree(ns); > - return ERR_PTR(err); > - } > + if (err) > + goto fail_free; > > ns->ns.ops = &utsns_operations; > > @@ -55,6 +68,13 @@ static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns, > ns->user_ns = get_user_ns(user_ns); > up_read(&uts_sem); > return ns; > + > +fail_free: > + kfree(ns); > +fail_dec: > + dec_uts_namespaces(user_ns); > +fail: > + return ERR_PTR(err); > } > > /* > @@ -85,6 +105,7 @@ void free_uts_ns(struct kref *kref) > struct uts_namespace *ns; > > ns = container_of(kref, struct uts_namespace, kref); > + dec_uts_namespaces(ns->user_ns); > put_user_ns(ns->user_ns); > ns_free_inum(&ns->ns); > kfree(ns); > -- > 2.8.3
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index 47733637741a..bed2506081fe 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -25,6 +25,7 @@ struct uid_gid_map { /* 64 bytes -- 1 cache line */ enum ucounts { UCOUNT_USER_NAMESPACES, UCOUNT_PID_NAMESPACES, + UCOUNT_UTS_NAMESPACES, UCOUNT_COUNTS, }; diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 02a03ead7afc..6b205c24e888 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -78,6 +78,7 @@ static int count_max = COUNT_MAX; static struct ctl_table userns_table[] = { UCOUNT_ENTRY("max_user_namespaces"), UCOUNT_ENTRY("max_pid_namespaces"), + UCOUNT_ENTRY("max_uts_namespaces"), { } }; #endif /* CONFIG_SYSCTL */ diff --git a/kernel/utsname.c b/kernel/utsname.c index 831ea7108232..4f13c0419d64 100644 --- a/kernel/utsname.c +++ b/kernel/utsname.c @@ -17,6 +17,16 @@ #include <linux/user_namespace.h> #include <linux/proc_ns.h> +static bool inc_uts_namespaces(struct user_namespace *ns) +{ + return inc_ucount(ns, UCOUNT_UTS_NAMESPACES); +} + +static void dec_uts_namespaces(struct user_namespace *ns) +{ + dec_ucount(ns, UCOUNT_UTS_NAMESPACES); +} + static struct uts_namespace *create_uts_ns(void) { struct uts_namespace *uts_ns; @@ -38,15 +48,18 @@ static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns, struct uts_namespace *ns; int err; + err = -ENFILE; + if (!inc_uts_namespaces(user_ns)) + goto fail; + + err = -ENOMEM; ns = create_uts_ns(); if (!ns) - return ERR_PTR(-ENOMEM); + goto fail_dec; err = ns_alloc_inum(&ns->ns); - if (err) { - kfree(ns); - return ERR_PTR(err); - } + if (err) + goto fail_free; ns->ns.ops = &utsns_operations; @@ -55,6 +68,13 @@ static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns, ns->user_ns = get_user_ns(user_ns); up_read(&uts_sem); return ns; + +fail_free: + kfree(ns); +fail_dec: + dec_uts_namespaces(user_ns); +fail: + return ERR_PTR(err); } /* @@ -85,6 +105,7 @@ void free_uts_ns(struct kref *kref) struct uts_namespace *ns; ns = container_of(kref, struct uts_namespace, kref); + dec_uts_namespaces(ns->user_ns); put_user_ns(ns->user_ns); ns_free_inum(&ns->ns); kfree(ns);
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> --- include/linux/user_namespace.h | 1 + kernel/user_namespace.c | 1 + kernel/utsname.c | 31 ++++++++++++++++++++++++++----- 3 files changed, 28 insertions(+), 5 deletions(-)