| Message ID | 20160721164014.17534-10-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> Thanks, Eric. > --- > fs/namespace.c | 19 ++++++++++++++++++- > include/linux/user_namespace.h | 1 + > kernel/user_namespace.c | 1 + > 3 files changed, 20 insertions(+), 1 deletion(-) > > diff --git a/fs/namespace.c b/fs/namespace.c > index aabe8e397fc3..3942ae6c34f5 100644 > --- a/fs/namespace.c > +++ b/fs/namespace.c > @@ -2718,9 +2718,20 @@ dput_out: > return retval; > } > > +static bool inc_mnt_namespaces(struct user_namespace *ns) > +{ > + return inc_ucount(ns, UCOUNT_MNT_NAMESPACES); > +} > + > +static void dec_mnt_namespaces(struct user_namespace *ns) > +{ > + dec_ucount(ns, UCOUNT_MNT_NAMESPACES); > +} > + > static void free_mnt_ns(struct mnt_namespace *ns) > { > ns_free_inum(&ns->ns); > + dec_mnt_namespaces(ns->user_ns); > put_user_ns(ns->user_ns); > kfree(ns); > } > @@ -2739,12 +2750,18 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns) > struct mnt_namespace *new_ns; > int ret; > > + if (!inc_mnt_namespaces(user_ns)) > + return ERR_PTR(-ENFILE); > + > new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL); > - if (!new_ns) > + if (!new_ns) { > + dec_mnt_namespaces(user_ns); > return ERR_PTR(-ENOMEM); > + } > ret = ns_alloc_inum(&new_ns->ns); > if (ret) { > kfree(new_ns); > + dec_mnt_namespaces(user_ns); > return ERR_PTR(ret); > } > new_ns->ns.ops = &mntns_operations; > diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h > index f86afa536baf..ee0e9d7b2e67 100644 > --- a/include/linux/user_namespace.h > +++ b/include/linux/user_namespace.h > @@ -28,6 +28,7 @@ enum ucounts { > UCOUNT_UTS_NAMESPACES, > UCOUNT_IPC_NAMESPACES, > UCOUNT_NET_NAMESPACES, > + UCOUNT_MNT_NAMESPACES, > UCOUNT_CGROUP_NAMESPACES, > UCOUNT_COUNTS, > }; > diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c > index e326ca722ae0..f6702d84afab 100644 > --- a/kernel/user_namespace.c > +++ b/kernel/user_namespace.c > @@ -81,6 +81,7 @@ static struct ctl_table userns_table[] = { > UCOUNT_ENTRY("max_uts_namespaces"), > UCOUNT_ENTRY("max_ipc_namespaces"), > UCOUNT_ENTRY("max_net_namespaces"), > + UCOUNT_ENTRY("max_mnt_namespaces"), > UCOUNT_ENTRY("max_cgroup_namespaces"), > { } > }; > -- > 2.8.3
diff --git a/fs/namespace.c b/fs/namespace.c index aabe8e397fc3..3942ae6c34f5 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2718,9 +2718,20 @@ dput_out: return retval; } +static bool inc_mnt_namespaces(struct user_namespace *ns) +{ + return inc_ucount(ns, UCOUNT_MNT_NAMESPACES); +} + +static void dec_mnt_namespaces(struct user_namespace *ns) +{ + dec_ucount(ns, UCOUNT_MNT_NAMESPACES); +} + static void free_mnt_ns(struct mnt_namespace *ns) { ns_free_inum(&ns->ns); + dec_mnt_namespaces(ns->user_ns); put_user_ns(ns->user_ns); kfree(ns); } @@ -2739,12 +2750,18 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns) struct mnt_namespace *new_ns; int ret; + if (!inc_mnt_namespaces(user_ns)) + return ERR_PTR(-ENFILE); + new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL); - if (!new_ns) + if (!new_ns) { + dec_mnt_namespaces(user_ns); return ERR_PTR(-ENOMEM); + } ret = ns_alloc_inum(&new_ns->ns); if (ret) { kfree(new_ns); + dec_mnt_namespaces(user_ns); return ERR_PTR(ret); } new_ns->ns.ops = &mntns_operations; diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index f86afa536baf..ee0e9d7b2e67 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -28,6 +28,7 @@ enum ucounts { UCOUNT_UTS_NAMESPACES, UCOUNT_IPC_NAMESPACES, UCOUNT_NET_NAMESPACES, + UCOUNT_MNT_NAMESPACES, UCOUNT_CGROUP_NAMESPACES, UCOUNT_COUNTS, }; diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index e326ca722ae0..f6702d84afab 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -81,6 +81,7 @@ static struct ctl_table userns_table[] = { UCOUNT_ENTRY("max_uts_namespaces"), UCOUNT_ENTRY("max_ipc_namespaces"), UCOUNT_ENTRY("max_net_namespaces"), + UCOUNT_ENTRY("max_mnt_namespaces"), UCOUNT_ENTRY("max_cgroup_namespaces"), { } };
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> --- fs/namespace.c | 19 ++++++++++++++++++- include/linux/user_namespace.h | 1 + kernel/user_namespace.c | 1 + 3 files changed, 20 insertions(+), 1 deletion(-)