diff options
| author | Elena Reshetova <elena.reshetova@intel.com> | 2017-08-02 00:03:58 +0000 |
|---|---|---|
| committer | Johannes Weiner <hannes@cmpxchg.org> | 2017-08-02 00:03:58 +0000 |
| commit | f21c7a389577e588b0b7c593d1722a7b164fa51a (patch) | |
| tree | 24f4fecc5144ba50e786103bb8314bdf5af86e06 | |
| parent | 460597722ae047ab22402378650f5d4bdca3fd22 (diff) | |
ipc: convert ipc_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.
Link: http://lkml.kernel.org/r/1499417992-3238-2-git-send-email-elena.reshetova@intel.com
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>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: <arozansk@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | include/linux/ipc_namespace.h | 5 | ||||
| -rw-r--r-- | ipc/msgutil.c | 2 | ||||
| -rw-r--r-- | ipc/namespace.c | 4 |
3 files changed, 6 insertions, 5 deletions
diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h index 65327ee0936b..e81445cc7c57 100644 --- a/include/linux/ipc_namespace.h +++ b/include/linux/ipc_namespace.h @@ -7,6 +7,7 @@ #include <linux/notifier.h> #include <linux/nsproxy.h> #include <linux/ns_common.h> +#include <linux/refcount.h> struct user_namespace; @@ -19,7 +20,7 @@ struct ipc_ids { }; struct ipc_namespace { - atomic_t count; + refcount_t count; struct ipc_ids ids[3]; int sem_ctls[4]; @@ -118,7 +119,7 @@ extern struct ipc_namespace *copy_ipcs(unsigned long flags, static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) { if (ns) - atomic_inc(&ns->count); + refcount_inc(&ns->count); return ns; } diff --git a/ipc/msgutil.c b/ipc/msgutil.c index bf74eaa5c39f..84598025a6ad 100644 --- a/ipc/msgutil.c +++ b/ipc/msgutil.c @@ -29,7 +29,7 @@ DEFINE_SPINLOCK(mq_lock); * and not CONFIG_IPC_NS. */ struct ipc_namespace init_ipc_ns = { - .count = ATOMIC_INIT(1), + .count = REFCOUNT_INIT(1), .user_ns = &init_user_ns, .ns.inum = PROC_IPC_INIT_INO, #ifdef CONFIG_IPC_NS diff --git a/ipc/namespace.c b/ipc/namespace.c index b4d80f9f7246..7af6e6b883b9 100644 --- a/ipc/namespace.c +++ b/ipc/namespace.c @@ -50,7 +50,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns, goto fail_free; ns->ns.ops = &ipcns_operations; - atomic_set(&ns->count, 1); + refcount_set(&ns->count, 1); ns->user_ns = get_user_ns(user_ns); ns->ucounts = ucounts; @@ -144,7 +144,7 @@ static void free_ipc_ns(struct ipc_namespace *ns) */ void put_ipc_ns(struct ipc_namespace *ns) { - if (atomic_dec_and_lock(&ns->count, &mq_lock)) { + if (refcount_dec_and_lock(&ns->count, &mq_lock)) { mq_clear_sbinfo(ns); spin_unlock(&mq_lock); mq_put_mnt(ns); |