[PATCH 4.19 187/191] help_next should increase position index

From: Greg Kroah-Hartman
Date: Fri Feb 21 2020 - 03:24:55 EST


From: Vasily Averin <vvs@xxxxxxxxxxxxx>

[ Upstream commit 9f198a2ac543eaaf47be275531ad5cbd50db3edf ]

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: Mike Marshall <hubcap@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/orangefs/orangefs-debugfs.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/orangefs/orangefs-debugfs.c b/fs/orangefs/orangefs-debugfs.c
index 0732cb08173e9..e24738c691f66 100644
--- a/fs/orangefs/orangefs-debugfs.c
+++ b/fs/orangefs/orangefs-debugfs.c
@@ -305,6 +305,7 @@ static void *help_start(struct seq_file *m, loff_t *pos)

static void *help_next(struct seq_file *m, void *v, loff_t *pos)
{
+ (*pos)++;
gossip_debug(GOSSIP_DEBUGFS_DEBUG, "help_next: start\n");

return NULL;
--
2.20.1