From 75020d6319eec226a5829359a23322a69f1d7525 Mon Sep 17 00:00:00 2001 From: Soheil Hassas Yeganeh Date: Sat, 14 Apr 2018 20:45:20 -0400 Subject: [PATCH] tcp: clear tp->packets_out when purging write queue Clear tp->packets_out when purging the write queue, otherwise tcp_rearm_rto() mistakenly assumes TCP write queue is not empty. This results in NULL pointer dereference. Also, remove the redundant `tp->packets_out = 0` from tcp_disconnect(), since tcp_disconnect() calls tcp_write_queue_purge(). Fixes: a27fd7a8ed38 (tcp: purge write queue upon RST) Reported-by: Subash Abhinov Kasiviswanathan Reported-by: Sami Farin Tested-by: Sami Farin Signed-off-by: Eric Dumazet Signed-off-by: Soheil Hassas Yeganeh Acked-by: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: Greg Kroah-Hartman --- include/net/tcp.h | 1 + net/ipv4/tcp.c | 1 - 2 files changed, 1 insertion(+), 1 deletion(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index d323d4fa742c..fb653736f335 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1616,6 +1616,7 @@ static inline void tcp_write_queue_purge(struct sock *sk) sk_mem_reclaim(sk); tcp_clear_all_retrans_hints(tcp_sk(sk)); tcp_init_send_head(sk); + tcp_sk(sk)->packets_out = 0; } static inline struct sk_buff *tcp_write_queue_head(const struct sock *sk) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index e8d8140cd33f..d023f879e7bb 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2354,7 +2354,6 @@ int tcp_disconnect(struct sock *sk, int flags) icsk->icsk_backoff = 0; tp->snd_cwnd = 2; icsk->icsk_probes_out = 0; - tp->packets_out = 0; tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; tp->snd_cwnd_cnt = 0; tp->window_clamp = 0; -- 2.20.1