tree a067d7017e45894601c946e8e271bfc0c4808be1
parent 90642ee9eb581a13569b1c0bd57e85d962215273
author Oliver Neukum <oneukum@suse.com> 1618991113 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1619610002 +0200

USB: CDC-ACM: fix poison/unpoison imbalance

commit a8b3b519618f30a87a304c4e120267ce6f8dc68a upstream.

suspend() does its poisoning conditionally, resume() does it
unconditionally. On a device with combined interfaces this
will balance, on a device with two interfaces the counter will
go negative and resubmission will fail.

Both actions need to be done conditionally.

Fixes: 6069e3e927c8f ("USB: cdc-acm: untangle a circular dependency between callback and softint")
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210421074513.4327-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>