3 files changed, 18 insertions, 10 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 5bf2040b25b1..00a748d14062 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -417,10 +417,12 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
 
                 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
                         tp->mtu_info = info;
-                        if (!sock_owned_by_user(sk))
+                        if (!sock_owned_by_user(sk)) {
                                 tcp_v4_mtu_reduced(sk);
-                        else
-                                set_bit(TCP_MTU_REDUCED_DEFERRED, &tp->tsq_flags);
+                        } else {
+                                if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED, &tp->tsq_flags))
+                                        sock_hold(sk);
+                        }
                         goto out;
                 }
 
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 20dfd892c86f..d04632673a9e 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -910,14 +910,18 @@ void tcp_release_cb(struct sock *sk)
         if (flags & (1UL << TCP_TSQ_DEFERRED))
                 tcp_tsq_handler(sk);
 
-        if (flags & (1UL << TCP_WRITE_TIMER_DEFERRED))
+        if (flags & (1UL << TCP_WRITE_TIMER_DEFERRED)) {
                 tcp_write_timer_handler(sk);
-
-        if (flags & (1UL << TCP_DELACK_TIMER_DEFERRED))
+                __sock_put(sk);
+        }
+        if (flags & (1UL << TCP_DELACK_TIMER_DEFERRED)) {
                 tcp_delack_timer_handler(sk);
-
-        if (flags & (1UL << TCP_MTU_REDUCED_DEFERRED))
+                __sock_put(sk);
+        }
+        if (flags & (1UL << TCP_MTU_REDUCED_DEFERRED)) {
                 sk->sk_prot->mtu_reduced(sk);
+                __sock_put(sk);
+        }
 }
 EXPORT_SYMBOL(tcp_release_cb);
 
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 6df36ad55a38..b774a03bd1dc 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -252,7 +252,8 @@ static void tcp_delack_timer(unsigned long data)
                 inet_csk(sk)->icsk_ack.blocked = 1;
                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_DELAYEDACKLOCKED);
                 /* deleguate our work to tcp_release_cb() */
-                set_bit(TCP_WRITE_TIMER_DEFERRED, &tcp_sk(sk)->tsq_flags);
+                if (!test_and_set_bit(TCP_DELACK_TIMER_DEFERRED, &tcp_sk(sk)->tsq_flags))
+                        sock_hold(sk);
         }
         bh_unlock_sock(sk);
         sock_put(sk);
@@ -481,7 +482,8 @@ static void tcp_write_timer(unsigned long data)
                 tcp_write_timer_handler(sk);
         } else {
                 /* deleguate our work to tcp_release_cb() */
-                set_bit(TCP_WRITE_TIMER_DEFERRED, &tcp_sk(sk)->tsq_flags);
+                if (!test_and_set_bit(TCP_WRITE_TIMER_DEFERRED, &tcp_sk(sk)->tsq_flags))
+                        sock_hold(sk);
         }
         bh_unlock_sock(sk);
         sock_put(sk);