[PATCH 4.9 22/41] intel_th: gth: Fix an off-by-one in output unassigning

From: Greg Kroah-Hartman
Date: Tue Apr 30 2019 - 08:08:25 EST


From: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>

commit 91d3f8a629849968dc91d6ce54f2d46abf4feb7f upstream.

Commit 9ed3f22223c3 ("intel_th: Don't reference unassigned outputs")
fixes a NULL dereference for all masters except the last one ("256+"),
which keeps the stale pointer after the output driver had been unassigned.

Fix the off-by-one.

Signed-off-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Fixes: 9ed3f22223c3 ("intel_th: Don't reference unassigned outputs")
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/hwtracing/intel_th/gth.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/hwtracing/intel_th/gth.c
+++ b/drivers/hwtracing/intel_th/gth.c
@@ -605,7 +605,7 @@ static void intel_th_gth_unassign(struct
othdev->output.port = -1;
othdev->output.active = false;
gth->output[port].output = NULL;
- for (master = 0; master < TH_CONFIGURABLE_MASTERS; master++)
+ for (master = 0; master <= TH_CONFIGURABLE_MASTERS; master++)
if (gth->master[master] == port)
gth->master[master] = -1;
spin_unlock(&gth->gth_lock);