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> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>zero-colors
parent
7483e5d420
commit
a2e0602c36
|
@ -7,6 +7,7 @@
|
||||||
#include <linux/notifier.h>
|
#include <linux/notifier.h>
|
||||||
#include <linux/nsproxy.h>
|
#include <linux/nsproxy.h>
|
||||||
#include <linux/ns_common.h>
|
#include <linux/ns_common.h>
|
||||||
|
#include <linux/refcount.h>
|
||||||
|
|
||||||
struct user_namespace;
|
struct user_namespace;
|
||||||
|
|
||||||
|
@ -19,7 +20,7 @@ struct ipc_ids {
|
||||||
};
|
};
|
||||||
|
|
||||||
struct ipc_namespace {
|
struct ipc_namespace {
|
||||||
atomic_t count;
|
refcount_t count;
|
||||||
struct ipc_ids ids[3];
|
struct ipc_ids ids[3];
|
||||||
|
|
||||||
int sem_ctls[4];
|
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)
|
static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
|
||||||
{
|
{
|
||||||
if (ns)
|
if (ns)
|
||||||
atomic_inc(&ns->count);
|
refcount_inc(&ns->count);
|
||||||
return ns;
|
return ns;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
|
@ -29,7 +29,7 @@ DEFINE_SPINLOCK(mq_lock);
|
||||||
* and not CONFIG_IPC_NS.
|
* and not CONFIG_IPC_NS.
|
||||||
*/
|
*/
|
||||||
struct ipc_namespace init_ipc_ns = {
|
struct ipc_namespace init_ipc_ns = {
|
||||||
.count = ATOMIC_INIT(1),
|
.count = REFCOUNT_INIT(1),
|
||||||
.user_ns = &init_user_ns,
|
.user_ns = &init_user_ns,
|
||||||
.ns.inum = PROC_IPC_INIT_INO,
|
.ns.inum = PROC_IPC_INIT_INO,
|
||||||
#ifdef CONFIG_IPC_NS
|
#ifdef CONFIG_IPC_NS
|
||||||
|
|
|
@ -50,7 +50,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
|
||||||
goto fail_free;
|
goto fail_free;
|
||||||
ns->ns.ops = &ipcns_operations;
|
ns->ns.ops = &ipcns_operations;
|
||||||
|
|
||||||
atomic_set(&ns->count, 1);
|
refcount_set(&ns->count, 1);
|
||||||
ns->user_ns = get_user_ns(user_ns);
|
ns->user_ns = get_user_ns(user_ns);
|
||||||
ns->ucounts = ucounts;
|
ns->ucounts = ucounts;
|
||||||
|
|
||||||
|
@ -144,7 +144,7 @@ static void free_ipc_ns(struct ipc_namespace *ns)
|
||||||
*/
|
*/
|
||||||
void put_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);
|
mq_clear_sbinfo(ns);
|
||||||
spin_unlock(&mq_lock);
|
spin_unlock(&mq_lock);
|
||||||
mq_put_mnt(ns);
|
mq_put_mnt(ns);
|
||||||
|
|
Loading…
Reference in New Issue