[PATCH 3.18 122/134] parport_pc: fix find_superio io compare code, should use equal test.

From: Greg Kroah-Hartman
Date: Fri Mar 22 2019 - 07:25:58 EST

3.18-stable review patch. If anyone has any objections, please let me know.


From: QiaoChong <qiaochong@xxxxxxxxxxx>

commit 21698fd57984cd28207d841dbdaa026d6061bceb upstream.

In the original code before 181bf1e815a2 the loop was continuing until
it finds the first matching superios[i].io and p->base.
But after 181bf1e815a2 the logic changed and the loop now returns the
pointer to the first mismatched array element which is then used in
get_superio_dma() and get_superio_irq() and thus returning the wrong
Fix the condition so that it now returns the correct pointer.

Fixes: 181bf1e815a2 ("parport_pc: clean up the modified while loops using for")
Cc: Alan Cox <alan@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: QiaoChong <qiaochong@xxxxxxxxxxx>
[rewrite the commit message]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/parport/parport_pc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/parport/parport_pc.c
+++ b/drivers/parport/parport_pc.c
@@ -1377,7 +1377,7 @@ static struct superio_struct *find_super
int i;
for (i = 0; i < NR_SUPERIOS; i++)
- if (superios[i].io != p->base)
+ if (superios[i].io == p->base)
return &superios[i];
return NULL;