From: Oliver Neukum Date: Wed, 15 Apr 2020 15:13:57 +0000 (+0200) Subject: cdc-acm: close race betrween suspend() and acm_softint X-Git-Tag: v5.7-rc3~2^2~14 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0afccd7601514c4b83d8cc58c740089cc447051d;p=thirdparty%2Fkernel%2Flinux.git cdc-acm: close race betrween suspend() and acm_softint Suspend increments a counter, then kills the URBs, then kills the scheduled work. The scheduled work, however, may reschedule the URBs. Fix this by having the work check the counter. Signed-off-by: Oliver Neukum Cc: stable Tested-by: Jonas Karlsson Link: https://lore.kernel.org/r/20200415151358.32664-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 84d6f7df09a4e..4ef68e6671aa6 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -557,14 +557,14 @@ static void acm_softint(struct work_struct *work) struct acm *acm = container_of(work, struct acm, work); if (test_bit(EVENT_RX_STALL, &acm->flags)) { - if (!(usb_autopm_get_interface(acm->data))) { + smp_mb(); /* against acm_suspend() */ + if (!acm->susp_count) { for (i = 0; i < acm->rx_buflimit; i++) usb_kill_urb(acm->read_urbs[i]); usb_clear_halt(acm->dev, acm->in); acm_submit_read_urbs(acm, GFP_KERNEL); - usb_autopm_put_interface(acm->data); + clear_bit(EVENT_RX_STALL, &acm->flags); } - clear_bit(EVENT_RX_STALL, &acm->flags); } if (test_and_clear_bit(EVENT_TTY_WAKEUP, &acm->flags))