| Message ID | 20230414122621.68269-1-duoming@zju.edu.cn (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] cxgb4: fix use after free bugs caused by circular dependency problem | expand |
On Fri, 14 Apr 2023 20:26:21 +0800 Duoming Zhou wrote: > The flower_stats_timer can schedule flower_stats_work and > flower_stats_work can also arm the flower_stats_timer. The > process is shown below: Please wait 24h for any comments, and if none arrive repost it with _correctly_ populated CC list. Run get_maintiner on the patch.
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_flower.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_flower.c index dd9be229819..d3541159487 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_flower.c +++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_flower.c @@ -1135,7 +1135,7 @@ void cxgb4_cleanup_tc_flower(struct adapter *adap) return; if (adap->flower_stats_timer.function) - del_timer_sync(&adap->flower_stats_timer); + timer_shutdown_sync(&adap->flower_stats_timer); cancel_work_sync(&adap->flower_stats_work); rhashtable_destroy(&adap->flower_tbl); adap->tc_flower_initialized = false;
The flower_stats_timer can schedule flower_stats_work and flower_stats_work can also arm the flower_stats_timer. The process is shown below: ----------- timer schedules work ------------ ch_flower_stats_cb() //timer handler schedule_work(&adap->flower_stats_work); ----------- work arms timer ------------ ch_flower_stats_handler() //workqueue callback function mod_timer(&adap->flower_stats_timer, ...); When the cxgb4 device is detaching, the timer and workqueue could still be rearmed. The process is shown below: (cleanup routine) | (timer and workqueue routine) remove_one() | free_some_resources() | ch_flower_stats_cb() //timer cxgb4_cleanup_tc_flower() | schedule_work() del_timer_sync() | | ch_flower_stats_handler() //workqueue | mod_timer() cancel_work_sync() | kfree(adapter) //FREE | ch_flower_stats_cb() //timer | adap->flower_stats_work //USE This patch changes del_timer_sync() to timer_shutdown_sync(), which could prevent rearming of the timer from the workqueue. Fixes: e0f911c81e93 ("cxgb4: fetch stats for offloaded tc flower flows") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> --- drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_flower.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)