[PATCH 4.9 010/223] media: dvb: usb: fix use after free in dvb_usb_device_exit

Greg Kroah-Hartman
2019-08-02T10:05:03Z

[ Upstream commit 6cf97230cd5f36b7665099083272595c55d72be7 ]

dvb_usb_device_exit() frees and uses the device name in that order.
Fix by storing the name in a buffer before freeing it.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Reported-by: syzbot+26ec41e9f788b3eba396@syzkaller.appspotmail.com
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/usb/dvb-usb/dvb-usb-init.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c
index 84308569e7dc..b3413404f91a 100644
--- a/drivers/media/usb/dvb-usb/dvb-usb-init.c
+++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c
@@ -287,12 +287,15 @@ EXPORT_SYMBOL(dvb_usb_device_init);
void dvb_usb_device_exit(struct usb_interface *intf)
{
struct dvb_usb_device *d = usb_get_intfdata(intf);
- const char *name = "generic DVB-USB module";
+ const char *default_name = "generic DVB-USB module";
+ char name[40];

usb_set_intfdata(intf, NULL);
if (d != NULL && d->desc != NULL) {
- name = d->desc->name;
+ strscpy(name, d->desc->name, sizeof(name));
dvb_usb_exit(d);
+ } else {
+ strscpy(name, default_name, sizeof(name));
}
info("%s successfully deinitialized and disconnected.", name);

--
2.20.1