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linux: add upstream patches

Signed-off-by: Stephan Raue <stephan@openelec.tv>
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sraue committed Oct 14, 2015
1 parent b5cee13 commit 97ea40a27ec54c4eef918487a96f0ba267830b4d
@@ -0,0 +1,63 @@
From 8f6a05588928ef61e751ca3cb008b9847fb6b83d Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Thu, 1 Oct 2015 05:39:26 -0700
Subject: [PATCH] inet: fix race in reqsk_queue_unlink()

reqsk_timer_handler() tests if icsk_accept_queue.listen_opt
is NULL at its beginning.

By the time it calls inet_csk_reqsk_queue_drop() and
reqsk_queue_unlink(), listener might have been closed and
inet_csk_listen_stop() had called reqsk_queue_yank_acceptq()
which sets icsk_accept_queue.listen_opt to NULL

We therefore need to correctly check listen_opt being NULL
after holding syn_wait_lock for proper synchronization.

Fixes: fa76ce7328b2 ("inet: get rid of central tcp/dccp listener timer")
Fixes: b357a364c57c ("inet: fix possible panic in reqsk_queue_unlink()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
---
net/ipv4/inet_connection_sock.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index e664706b350c..37c8b45af44b 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -568,21 +568,22 @@ EXPORT_SYMBOL(inet_rtx_syn_ack);
static bool reqsk_queue_unlink(struct request_sock_queue *queue,
struct request_sock *req)
{
- struct listen_sock *lopt = queue->listen_opt;
struct request_sock **prev;
+ struct listen_sock *lopt;
bool found = false;

spin_lock(&queue->syn_wait_lock);
-
- for (prev = &lopt->syn_table[req->rsk_hash]; *prev != NULL;
- prev = &(*prev)->dl_next) {
- if (*prev == req) {
- *prev = req->dl_next;
- found = true;
- break;
+ lopt = queue->listen_opt;
+ if (lopt) {
+ for (prev = &lopt->syn_table[req->rsk_hash]; *prev != NULL;
+ prev = &(*prev)->dl_next) {
+ if (*prev == req) {
+ *prev = req->dl_next;
+ found = true;
+ break;
+ }
}
}
-
spin_unlock(&queue->syn_wait_lock);
if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer))
reqsk_put(req);
--
2.4.3

@@ -0,0 +1,40 @@
From 05676fe53c9f26fe703c57b14bdd0807e23cc33b Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Thu, 13 Aug 2015 15:44:51 -0700
Subject: [PATCH 1/2] inet: fix potential deadlock in reqsk_queue_unlink()

When replacing del_timer() with del_timer_sync(), I introduced
a deadlock condition :

reqsk_queue_unlink() is called from inet_csk_reqsk_queue_drop()

inet_csk_reqsk_queue_drop() can be called from many contexts,
one being the timer handler itself (reqsk_timer_handler()).

In this case, del_timer_sync() loops forever.

Simple fix is to test if timer is pending.

Fixes: 2235f2ac75fd ("inet: fix races with reqsk timers")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv4/inet_connection_sock.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index b27fc401c6a9..e664706b350c 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -584,7 +584,7 @@ static bool reqsk_queue_unlink(struct request_sock_queue *queue,
}

spin_unlock(&queue->syn_wait_lock);
- if (del_timer_sync(&req->rsk_timer))
+ if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer))
reqsk_put(req);
return found;
}
--
2.4.3

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