[PATCH 10/17] net: convert in_device.refcnt from atomic_t to refcount_t
From: Elena Reshetova <elena.reshetova@intel.com>
Date: 2017-06-28 11:56:04
Also in:
bridge, lkml
Subsystem:
networking drivers, networking [general], networking [ipv4/ipv6], the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
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 <redacted> Signed-off-by: Kees Cook <redacted> Signed-off-by: David Windsor <redacted> --- include/linux/inetdevice.h | 11 ++++++----- net/ipv4/devinet.c | 2 +- 2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index a2e9d6e..4b9d135 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h@@ -11,6 +11,7 @@ #include <linux/timer.h> #include <linux/sysctl.h> #include <linux/rtnetlink.h> +#include <linux/refcount.h> struct ipv4_devconf { void *sysctl;
@@ -22,7 +23,7 @@ struct ipv4_devconf { struct in_device { struct net_device *dev; - atomic_t refcnt; + refcount_t refcnt; int dead; struct in_ifaddr *ifa_list; /* IP ifaddr chain */
@@ -212,7 +213,7 @@ static inline struct in_device *in_dev_get(const struct net_device *dev) rcu_read_lock(); in_dev = __in_dev_get_rcu(dev); if (in_dev) - atomic_inc(&in_dev->refcnt); + refcount_inc(&in_dev->refcnt); rcu_read_unlock(); return in_dev; }
@@ -233,12 +234,12 @@ void in_dev_finish_destroy(struct in_device *idev); static inline void in_dev_put(struct in_device *idev) { - if (atomic_dec_and_test(&idev->refcnt)) + if (refcount_dec_and_test(&idev->refcnt)) in_dev_finish_destroy(idev); } -#define __in_dev_put(idev) atomic_dec(&(idev)->refcnt) -#define in_dev_hold(idev) atomic_inc(&(idev)->refcnt) +#define __in_dev_put(idev) refcount_dec(&(idev)->refcnt) +#define in_dev_hold(idev) refcount_inc(&(idev)->refcnt) #endif /* __KERNEL__ */
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index df14815..16c5e22 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c@@ -251,7 +251,7 @@ static struct in_device *inetdev_init(struct net_device *dev) /* Reference in_dev->dev */ dev_hold(dev); /* Account for reference dev->ip_ptr (below) */ - in_dev_hold(in_dev); + refcount_set(&in_dev->refcnt, 1); err = devinet_sysctl_register(in_dev); if (err) {
--
2.7.4