diff options
| author |   Elena Reshetova <elena.reshetova@intel.com> | 2017-02-20 12:19:00 +0200 |
|---|---|---|
| committer |   Tejun Heo <tj@kernel.org> | 2017-03-06 14:55:22 -0500 |
| commit | 387ad9674b0013c8756ad20d854ff005b0c313ad (patch) | |
| tree | 4e019a943d277232afdd5421276cc48829008214 /include/linux/cgroup.h | |
| parent | Linux 4.11-rc1 (diff) | |
| download | linux-dev-387ad9674b0013c8756ad20d854ff005b0c313ad.tar.xz linux-dev-387ad9674b0013c8756ad20d854ff005b0c313ad.zip | |
kernel: convert cgroup_namespace.count from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'include/linux/cgroup.h')
| -rw-r--r-- | include/linux/cgroup.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index f6b43fbb141c..44129793c7b8 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -22,6 +22,7 @@ #include <linux/ns_common.h> #include <linux/nsproxy.h> #include <linux/user_namespace.h> +#include <linux/refcount.h> #include <linux/cgroup-defs.h> @@ -640,7 +641,7 @@ static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {} #endif /* CONFIG_CGROUP_DATA */ struct cgroup_namespace { - atomic_t count; + refcount_t count; struct ns_common ns; struct user_namespace *user_ns; struct ucounts *ucounts; @@ -675,12 +676,12 @@ copy_cgroup_ns(unsigned long flags, struct user_namespace *user_ns, static inline void get_cgroup_ns(struct cgroup_namespace *ns) { if (ns) - atomic_inc(&ns->count); + refcount_inc(&ns->count); } static inline void put_cgroup_ns(struct cgroup_namespace *ns) { - if (ns && atomic_dec_and_test(&ns->count)) + if (ns && refcount_dec_and_test(&ns->count)) free_cgroup_ns(ns); } |