On Fri, Aug 21, 2020 at 1:28 AM Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote: > > 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]. > > Ganapathi Bhat proposed a possibly cleaner fix, but it seems that > that fix was forgotten [2]. > > "grep -FrB1 'del_timer' drivers/ | grep -FA1 '.function)'" says that > currently there are 28 locations which call del_timer[_sync]() only if > that timer's function field was initialized (because timer_setup() sets > that timer's function field). Therefore, let's use same approach here. > > [1] https://syzkaller.appspot.com/bug?id=26525f643f454dd7be0078423e3cdb0d57744959 > [2] https://lkml.kernel.org/r/CA+ASDXMHt2gq9Hy+iP_BYkWXsSreWdp3_bAfMkNcuqJ3K+-jbQ@xxxxxxxxxxxxxx > > Reported-by: syzbot <syzbot+dc4127f950da51639216@xxxxxxxxxxxxxxxxxxxxxxxxx> > Cc: Ganapathi Bhat <ganapathi.bhat@xxxxxxx> > Cc: Brian Norris <briannorris@xxxxxxxxxxxx> > Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> This seems good to me: Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx> > --- > 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 6f3cfde4654c..426e39d4ccf0 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.hold_timer.function) > + 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; > } > -- > 2.18.4 >
