This is a note to let you know that I've just added the patch titled
cdc-acm: close race betrween suspend() and acm_softint
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 0afccd7601514c4b83d8cc58c740089cc447051d Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@xxxxxxxx>
Date: Wed, 15 Apr 2020 17:13:57 +0200
Subject: 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 <oneukum@xxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Tested-by: Jonas Karlsson <jonas.karlsson@xxxxxxxx>
Link: https://lore.kernel.org/r/20200415151358.32664-1-oneukum@xxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/class/cdc-acm.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 84d6f7df09a4..4ef68e6671aa 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))
--
2.26.1
