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-rw-r--r--main/linux-rpi/0001-inet-fix-potential-deadlock-in-reqsk_queue_unlink.patch40
1 files changed, 40 insertions, 0 deletions
diff --git a/main/linux-rpi/0001-inet-fix-potential-deadlock-in-reqsk_queue_unlink.patch b/main/linux-rpi/0001-inet-fix-potential-deadlock-in-reqsk_queue_unlink.patch
new file mode 100644
index 0000000000..fdd23d5cc5
--- /dev/null
+++ b/main/linux-rpi/0001-inet-fix-potential-deadlock-in-reqsk_queue_unlink.patch
@@ -0,0 +1,40 @@
+From 83fccfc3940c4a2db90fd7e7079f5b465cd8c6af Mon Sep 17 00:00:00 2001
+From: Eric Dumazet <edumazet@google.com>
+Date: Thu, 13 Aug 2015 15:44:51 -0700
+Subject: [PATCH] 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 05e3145..1349571 100644
+--- a/net/ipv4/inet_connection_sock.c
++++ b/net/ipv4/inet_connection_sock.c
+@@ -593,7 +593,7 @@ 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;
+ }
+--
+2.6.0
+