[PATCH 5.15 07/25] batman-adv: tp_meter: handle seqno wrap-around for fast recovery detection

[Sven Eckelmann <sven@narfation.org>]

commit f54c85ed42a1b27a516cf2a4728f5a612b799e07 upstream.

The recover variable and the last_sent sequence number are initialized on
purpose as a really high value which will wrap-around after the first 2000
bytes. The fast recovery precondition must therefore not use simple integer
comparisons but use helpers which are aware of the sequence number
wrap-arounds.

Cc: stable@kernel.org
Fixes: 33a3bb4a3345 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
 net/batman-adv/tp_meter.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c
index 1fc8d6e6f99b3..7385cd02abf9f 100644
--- a/net/batman-adv/tp_meter.c
+++ b/net/batman-adv/tp_meter.c
@@ -733,7 +733,7 @@ static void batadv_tp_recv_ack(struct batadv_priv *bat_priv,
 		if (atomic_read(&tp_vars->dup_acks) != 3)
 			goto out;
 
-		if (tp_vars->recover >= recv_ack)
+		if (!batadv_seq_before(tp_vars->recover, recv_ack))
 			goto out;
 
 		/* if this is the third duplicate ACK do Fast Retransmit */
-- 
2.47.3