Re: [PATCH v2] mwifiex: don't call del_timer_sync() on uninitialized timer
From: Brian Norris <briannorris@chromium.org>
Date: 2020-08-24 18:53:15
Also in:
linux-usb, linux-wireless, lkml
On Fri, Aug 21, 2020 at 1:28 AM Tetsuo Handa [off-list ref] 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@mail.gmail.com Reported-by: syzbot <redacted> Cc: Ganapathi Bhat <redacted> Cc: Brian Norris <briannorris@chromium.org> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
This seems good to me: Reviewed-by: Brian Norris <briannorris@chromium.org>
quoted hunk ↗ jump to hunk
--- 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