syzbot is reporting that del_timer_sync() is called from mwifiex_usb_cleanup_tx_aggr() from mwifiex_unregister_dev() without checking timer_setup() from mwifiex_usb_tx_init() was called [1]. Since mwifiex_usb_prepare_tx_aggr_skb() is calling del_timer() if is_hold_timer_set == true, use the same condition for del_timer_sync(). [1] https://syzkaller.appspot.com/bug?id=fdeef9cf7348be8b8ab5b847f2ed993aba8ea7b6 Reported-by: syzbot <syzbot+373e6719b49912399d21@xxxxxxxxxxxxxxxxxxxxxxxxx> Cc: Ganapathi Bhat <gbhat@xxxxxxxxxxx> Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> --- A patch from Ganapathi Bhat ( https://patchwork.kernel.org/patch/10990275/ ) is stalling at https://lore.kernel.org/linux-usb/MN2PR18MB2637D7C742BC235FE38367F0A09C0@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ . syzbot by now got this report for 10000 times. Do we want to go with this simple patch? drivers/net/wireless/marvell/mwifiex/usb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/marvell/mwifiex/usb.c b/drivers/net/wireless/marvell/mwifiex/usb.c index 6f3cfde..04a1461 100644 --- a/drivers/net/wireless/marvell/mwifiex/usb.c +++ b/drivers/net/wireless/marvell/mwifiex/usb.c @@ -1353,7 +1353,8 @@ static void mwifiex_usb_cleanup_tx_aggr(struct mwifiex_adapter *adapter) skb_dequeue(&port->tx_aggr.aggr_list))) mwifiex_write_data_complete(adapter, skb_tmp, 0, -1); - del_timer_sync(&port->tx_aggr.timer_cnxt.hold_timer); + if (port->tx_aggr.timer_cnxt.is_hold_timer_set) + del_timer_sync(&port->tx_aggr.timer_cnxt.hold_timer); port->tx_aggr.timer_cnxt.is_hold_timer_set = false; port->tx_aggr.timer_cnxt.hold_tmo_msecs = 0; } -- 1.8.3.1
