tg in throtl_select_dispatch is used first and then do check. Since tg
may be NULL, it has potential NULL pointer dereference risk. So fix it.
Signed-off-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
Reviewed-by: Jiufei Xue <jiufei.xue@xxxxxxxxxxxxxxxxx>
---
block/blk-throttle.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 9052f4e..a0bae2c 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -1228,7 +1228,7 @@ static int throtl_select_dispatch(struct throtl_service_queue *parent_sq)
while (1) {
struct throtl_grp *tg = throtl_rb_first(parent_sq);
- struct throtl_service_queue *sq = &tg->service_queue;
+ struct throtl_service_queue *sq;
if (!tg)
break;
@@ -1240,6 +1240,7 @@ static int throtl_select_dispatch(struct throtl_service_queue *parent_sq)
nr_disp += throtl_dispatch_tg(tg);
+ sq = &tg->service_queue;
if (sq->nr_queued[0] || sq->nr_queued[1])
tg_update_disptime(tg);
--
1.9.4
