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authorReshetova, Elena <elena.reshetova@intel.com>2017-06-30 13:08:00 +0300
committerDavid S. Miller <davem@davemloft.net>2017-07-01 07:39:08 -0700
commit14afee4b6092fde451ee17604e5f5c89da33e71e (patch)
tree19be7a1d72a1b25c5e5366c1213cdda982aacca2 /net/ipv4
parent2638595afccf6554bfe55268ff9b2d3ac3dff2e6 (diff)
net: convert sock.sk_wmem_alloc 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: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/af_inet.c2
-rw-r--r--net/ipv4/esp4.c2
-rw-r--r--net/ipv4/ip_output.c6
-rw-r--r--net/ipv4/tcp.c4
-rw-r--r--net/ipv4/tcp_offload.c2
-rw-r--r--net/ipv4/tcp_output.c15
6 files changed, 15 insertions, 16 deletions
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 58925b6597de..76c2077c3f5b 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -150,7 +150,7 @@ void inet_sock_destruct(struct sock *sk)
}
WARN_ON(atomic_read(&sk->sk_rmem_alloc));
- WARN_ON(atomic_read(&sk->sk_wmem_alloc));
+ WARN_ON(refcount_read(&sk->sk_wmem_alloc));
WARN_ON(sk->sk_wmem_queued);
WARN_ON(sk->sk_forward_alloc);
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 1f18b4650253..0cbee0a666ff 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -307,7 +307,7 @@ int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *
skb->data_len += tailen;
skb->truesize += tailen;
if (sk)
- atomic_add(tailen, &sk->sk_wmem_alloc);
+ refcount_add(tailen, &sk->sk_wmem_alloc);
goto out;
}
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 532b36e9ce2a..2e61e2af251a 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1037,7 +1037,7 @@ alloc_new_skb:
(flags & MSG_DONTWAIT), &err);
} else {
skb = NULL;
- if (atomic_read(&sk->sk_wmem_alloc) <=
+ if (refcount_read(&sk->sk_wmem_alloc) <=
2 * sk->sk_sndbuf)
skb = sock_wmalloc(sk,
alloclen + hh_len + 15, 1,
@@ -1145,7 +1145,7 @@ alloc_new_skb:
skb->len += copy;
skb->data_len += copy;
skb->truesize += copy;
- atomic_add(copy, &sk->sk_wmem_alloc);
+ refcount_add(copy, &sk->sk_wmem_alloc);
}
offset += copy;
length -= copy;
@@ -1369,7 +1369,7 @@ ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
skb->len += len;
skb->data_len += len;
skb->truesize += len;
- atomic_add(len, &sk->sk_wmem_alloc);
+ refcount_add(len, &sk->sk_wmem_alloc);
offset += len;
size -= len;
}
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 4793fb78d93b..fae45e402742 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -664,7 +664,7 @@ static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
return skb->len < size_goal &&
sysctl_tcp_autocorking &&
skb != tcp_write_queue_head(sk) &&
- atomic_read(&sk->sk_wmem_alloc) > skb->truesize;
+ refcount_read(&sk->sk_wmem_alloc) > skb->truesize;
}
static void tcp_push(struct sock *sk, int flags, int mss_now,
@@ -692,7 +692,7 @@ static void tcp_push(struct sock *sk, int flags, int mss_now,
/* It is possible TX completion already happened
* before we set TSQ_THROTTLED.
*/
- if (atomic_read(&sk->sk_wmem_alloc) > skb->truesize)
+ if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize)
return;
}
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index bc68da38ea86..11f69bbf9307 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -152,7 +152,7 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
swap(gso_skb->sk, skb->sk);
swap(gso_skb->destructor, skb->destructor);
sum_truesize += skb->truesize;
- atomic_add(sum_truesize - gso_skb->truesize,
+ refcount_add(sum_truesize - gso_skb->truesize,
&skb->sk->sk_wmem_alloc);
}
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 9a9c395b6235..1d79137f3795 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -861,12 +861,11 @@ void tcp_wfree(struct sk_buff *skb)
struct sock *sk = skb->sk;
struct tcp_sock *tp = tcp_sk(sk);
unsigned long flags, nval, oval;
- int wmem;
/* Keep one reference on sk_wmem_alloc.
* Will be released by sk_free() from here or tcp_tasklet_func()
*/
- wmem = atomic_sub_return(skb->truesize - 1, &sk->sk_wmem_alloc);
+ WARN_ON(refcount_sub_and_test(skb->truesize - 1, &sk->sk_wmem_alloc));
/* If this softirq is serviced by ksoftirqd, we are likely under stress.
* Wait until our queues (qdisc + devices) are drained.
@@ -875,7 +874,7 @@ void tcp_wfree(struct sk_buff *skb)
* - chance for incoming ACK (processed by another cpu maybe)
* to migrate this flow (skb->ooo_okay will be eventually set)
*/
- if (wmem >= SKB_TRUESIZE(1) && this_cpu_ksoftirqd() == current)
+ if (refcount_read(&sk->sk_wmem_alloc) >= SKB_TRUESIZE(1) && this_cpu_ksoftirqd() == current)
goto out;
for (oval = READ_ONCE(sk->sk_tsq_flags);; oval = nval) {
@@ -925,7 +924,7 @@ enum hrtimer_restart tcp_pace_kick(struct hrtimer *timer)
if (nval != oval)
continue;
- if (!atomic_inc_not_zero(&sk->sk_wmem_alloc))
+ if (!refcount_inc_not_zero(&sk->sk_wmem_alloc))
break;
/* queue this socket to tasklet queue */
tsq = this_cpu_ptr(&tsq_tasklet);
@@ -1045,7 +1044,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
skb->sk = sk;
skb->destructor = skb_is_tcp_pure_ack(skb) ? __sock_wfree : tcp_wfree;
skb_set_hash_from_sk(skb, sk);
- atomic_add(skb->truesize, &sk->sk_wmem_alloc);
+ refcount_add(skb->truesize, &sk->sk_wmem_alloc);
skb_set_dst_pending_confirm(skb, sk->sk_dst_pending_confirm);
@@ -2176,7 +2175,7 @@ static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb,
limit = min_t(u32, limit, sysctl_tcp_limit_output_bytes);
limit <<= factor;
- if (atomic_read(&sk->sk_wmem_alloc) > limit) {
+ if (refcount_read(&sk->sk_wmem_alloc) > limit) {
/* Always send the 1st or 2nd skb in write queue.
* No need to wait for TX completion to call us back,
* after softirq/tasklet schedule.
@@ -2192,7 +2191,7 @@ static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb,
* test again the condition.
*/
smp_mb__after_atomic();
- if (atomic_read(&sk->sk_wmem_alloc) > limit)
+ if (refcount_read(&sk->sk_wmem_alloc) > limit)
return true;
}
return false;
@@ -2812,7 +2811,7 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs)
/* Do not sent more than we queued. 1/4 is reserved for possible
* copying overhead: fragmentation, tunneling, mangling etc.
*/
- if (atomic_read(&sk->sk_wmem_alloc) >
+ if (refcount_read(&sk->sk_wmem_alloc) >
min_t(u32, sk->sk_wmem_queued + (sk->sk_wmem_queued >> 2),
sk->sk_sndbuf))
return -EAGAIN;