diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-08-18 12:08:07 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-08-18 15:14:07 -0700 |
| commit | 9620fef27ed2cdb37bf6fd028f32bea2ef5119a8 (patch) | |
| tree | 7d4b243d0f353b98fd379d0d6ad800d734506e30 | |
| parent | 633cefe390e59e9449dc88707235e57ac76b5c38 (diff) | |
ipv4: convert dst_metrics.refcnt 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: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/dst.h | 3 | ||||
| -rw-r--r-- | net/core/dst.c | 6 | ||||
| -rw-r--r-- | net/ipv4/fib_semantics.c | 4 | ||||
| -rw-r--r-- | net/ipv4/route.c | 4 |
4 files changed, 9 insertions, 8 deletions
diff --git a/include/net/dst.h b/include/net/dst.h index f73611ec4017..93568bd0a352 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -14,6 +14,7 @@ #include <linux/rcupdate.h> #include <linux/bug.h> #include <linux/jiffies.h> +#include <linux/refcount.h> #include <net/neighbour.h> #include <asm/processor.h> @@ -107,7 +108,7 @@ struct dst_entry { struct dst_metrics { u32 metrics[RTAX_MAX]; - atomic_t refcnt; + refcount_t refcnt; }; extern const struct dst_metrics dst_default_metrics; diff --git a/net/core/dst.c b/net/core/dst.c index 00aa972ad1a1..d6ead757c258 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -55,7 +55,7 @@ const struct dst_metrics dst_default_metrics = { * We really want to avoid false sharing on this variable, and catch * any writes on it. */ - .refcnt = ATOMIC_INIT(1), + .refcnt = REFCOUNT_INIT(1), }; void dst_init(struct dst_entry *dst, struct dst_ops *ops, @@ -213,7 +213,7 @@ u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old) struct dst_metrics *old_p = (struct dst_metrics *)__DST_METRICS_PTR(old); unsigned long prev, new; - atomic_set(&p->refcnt, 1); + refcount_set(&p->refcnt, 1); memcpy(p->metrics, old_p->metrics, sizeof(p->metrics)); new = (unsigned long) p; @@ -225,7 +225,7 @@ u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old) if (prev & DST_METRICS_READ_ONLY) p = NULL; } else if (prev & DST_METRICS_REFCOUNTED) { - if (atomic_dec_and_test(&old_p->refcnt)) + if (refcount_dec_and_test(&old_p->refcnt)) kfree(old_p); } } diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index d521caf57385..394d800db50c 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -220,7 +220,7 @@ static void free_fib_info_rcu(struct rcu_head *head) } endfor_nexthops(fi); m = fi->fib_metrics; - if (m != &dst_default_metrics && atomic_dec_and_test(&m->refcnt)) + if (m != &dst_default_metrics && refcount_dec_and_test(&m->refcnt)) kfree(m); kfree(fi); } @@ -1090,7 +1090,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg, kfree(fi); return ERR_PTR(err); } - atomic_set(&fi->fib_metrics->refcnt, 1); + refcount_set(&fi->fib_metrics->refcnt, 1); } else { fi->fib_metrics = (struct dst_metrics *)&dst_default_metrics; } diff --git a/net/ipv4/route.c b/net/ipv4/route.c index d400c0543106..872b4cb136d3 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1398,7 +1398,7 @@ static void ipv4_dst_destroy(struct dst_entry *dst) struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst); struct rtable *rt = (struct rtable *) dst; - if (p != &dst_default_metrics && atomic_dec_and_test(&p->refcnt)) + if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt)) kfree(p); if (!list_empty(&rt->rt_uncached)) { @@ -1456,7 +1456,7 @@ static void rt_set_nexthop(struct rtable *rt, __be32 daddr, dst_init_metrics(&rt->dst, fi->fib_metrics->metrics, true); if (fi->fib_metrics != &dst_default_metrics) { rt->dst._metrics |= DST_METRICS_REFCOUNTED; - atomic_inc(&fi->fib_metrics->refcnt); + refcount_inc(&fi->fib_metrics->refcnt); } #ifdef CONFIG_IP_ROUTE_CLASSID rt->dst.tclassid = nh->nh_tclassid; |