[PATCH 5.4 87/90] l2t_seq_next should increase position index

From: Greg Kroah-Hartman
Date: Mon Feb 03 2020 - 11:37:21 EST


From: Vasily Averin <vvs@xxxxxxxxxxxxx>

[ Upstream commit 66018a102f7756cf72db4d2704e1b93969d9d332 ]

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@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/chelsio/cxgb4/l2t.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb4/l2t.c b/drivers/net/ethernet/chelsio/cxgb4/l2t.c
index 1a407d3c1d67c..e6fe2870137b0 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;
}

--
2.20.1