From 3145dbf8a3ad843ffb4beace18dfb6ff4da53499 Mon Sep 17 00:00:00 2001
From: Vasily Averin <vvs@virtuozzo.com>
Date: Thu, 23 Jan 2020 10:11:13 +0300
Subject: [PATCH] l2t_seq_next should increase position index

commit 66018a102f7756cf72db4d2704e1b93969d9d332 upstream.

if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/net/ethernet/chelsio/cxgb4/l2t.c b/drivers/net/ethernet/chelsio/cxgb4/l2t.c
index 1a407d3c1d67..e6fe2870137b 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/l2t.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/l2t.c
@@ -682,8 +682,7 @@ static void *l2t_seq_start(struct seq_file *seq, loff_t *pos)
 static void *l2t_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
 	v = l2t_get_idx(seq, *pos);
-	if (v)
-		++*pos;
+	++(*pos);
 	return v;
 }
 
-- 
2.7.4