summaryrefslogtreecommitdiffstats
path: root/drivers/usb/class
diff options
context:
space:
mode:
authorOliver Neukum <oneukum@suse.com>2016-04-04 14:30:53 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-04-13 11:53:07 -0700
commit2a14759a03a0a57b2fc99b1e416180788b8ba24c (patch)
tree0c7ddf79ac0ecf03dfd6ba25f8549dbf64fac276 /drivers/usb/class
parentbf16200689118d19de1b8d2a3c314fc21f5dc7bb (diff)
downloadlinux-2a14759a03a0a57b2fc99b1e416180788b8ba24c.tar.bz2
cdc-acm: fix crash if flushed with nothing buffered
Under some circumstances acm_tty_flush_chars() is called with no buffer to flush. We simply need to do nothing. Signed-off-by: Oliver Neukum <ONeukum@suse.com> Reported-by: Torsten Hilbrich <torsten.hilbrich@secunet.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/class')
-rw-r--r--drivers/usb/class/cdc-acm.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 83fd30b0577c..a6c4a1b895bd 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -744,11 +744,15 @@ static void acm_tty_flush_chars(struct tty_struct *tty)
int err;
unsigned long flags;
+ if (!cur) /* nothing to do */
+ return;
+
acm->putbuffer = NULL;
err = usb_autopm_get_interface_async(acm->control);
spin_lock_irqsave(&acm->write_lock, flags);
if (err < 0) {
cur->use = 0;
+ acm->putbuffer = cur;
goto out;
}