From: Vasily Averin <vvs@virtuozzo.com>
Date: Thu, 23 Jan 2020 10:11:13 +0300
Subject: l2t_seq_next should increase position index
Patch-mainline: v5.5
Git-commit: 66018a102f7756cf72db4d2704e1b93969d9d332
References: bsc#1154353

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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/chelsio/cxgb4/l2t.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/net/ethernet/chelsio/cxgb4/l2t.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/l2t.c
@@ -678,8 +678,7 @@ static void *l2t_seq_start(struct seq_fi
 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;
 }