diff options
| author | Oliver Neukum <oneukum@suse.com> | 2024-03-14 12:50:48 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-26 14:56:33 +0100 |
| commit | 339f83612f3a569b194680768b22bf113c26a29d (patch) | |
| tree | ee684e37856195b5893dcdee01ae963e6fd0fee8 | |
| parent | 5d69a3b54e5a630c90d82a4c2bdce3d53dc78710 (diff) | |
usb: cdc-wdm: close race between read and workqueue
wdm_read() cannot race with itself. However, in
service_outstanding_interrupt() it can race with the
workqueue, which can be triggered by error handling.
Hence we need to make sure that the WDM_RESPONDING
flag is not just only set but tested.
Fixes: afba937e540c9 ("USB: CDC WDM driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Link: https://lore.kernel.org/r/20240314115132.3907-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/class/cdc-wdm.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index c553decb5461..c8262e2f2917 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -485,6 +485,7 @@ out_free_mem: static int service_outstanding_interrupt(struct wdm_device *desc) { int rv = 0; + int used; /* submit read urb only if the device is waiting for it */ if (!desc->resp_count || !--desc->resp_count) @@ -499,7 +500,10 @@ static int service_outstanding_interrupt(struct wdm_device *desc) goto out; } - set_bit(WDM_RESPONDING, &desc->flags); + used = test_and_set_bit(WDM_RESPONDING, &desc->flags); + if (used) + goto out; + spin_unlock_irq(&desc->iuspin); rv = usb_submit_urb(desc->response, GFP_KERNEL); spin_lock_irq(&desc->iuspin); |