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authorPeter Hurley <peter@hurleysoftware.com>2013-09-18 20:42:39 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-09-25 18:08:34 -0700
commite3bfea23a62dccfd12875a6cc24fa5c77e8a3c07 (patch)
tree004e21ee4cc60fc6a9dd9b57991dd968047fc0f8
parent103fcbe2eeb56d6ee693c573eac81e398fa276bd (diff)
downloadop-kernel-dev-e3bfea23a62dccfd12875a6cc24fa5c77e8a3c07.zip
op-kernel-dev-e3bfea23a62dccfd12875a6cc24fa5c77e8a3c07.tar.gz
tty: Prevent tty_port destruction if tty not released
If the tty driver mistakenly drops the last port reference before the tty has been released, issue a diagnostic and abort the port destruction. This will leak memory and may zombify the port, but might otherwise keep the machine in runnable state. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/tty/tty_port.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index f597e88..7efbca4 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -140,6 +140,10 @@ EXPORT_SYMBOL(tty_port_destroy);
static void tty_port_destructor(struct kref *kref)
{
struct tty_port *port = container_of(kref, struct tty_port, kref);
+
+ /* check if last port ref was dropped before tty release */
+ if (WARN_ON(port->itty))
+ return;
if (port->xmit_buf)
free_page((unsigned long)port->xmit_buf);
tty_port_destroy(port);
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