From: Johan Hovold <johan@kernel.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
Pete Zaitcev <zaitcev@redhat.com>,
Johan Hovold <johan@kernel.org>, stable <stable@vger.kernel.org>,
syzbot+cd24df4d075c319ebfc5@syzkaller.appspotmail.com
Subject: [PATCH] USB: usblp: fix use-after-free on disconnect
Date: Tue, 15 Oct 2019 19:55:22 +0200 [thread overview]
Message-ID: <20191015175522.18490-1-johan@kernel.org> (raw)
In-Reply-To: <000000000000f6ca4c0594f4f3d4@google.com>
A recent commit addressing a runtime PM use-count regression, introduced
a use-after-free by not making sure we held a reference to the struct
usb_interface for the lifetime of the driver data.
Fixes: 9a31535859bf ("USB: usblp: fix runtime PM after driver unbind")
Cc: stable <stable@vger.kernel.org>
Reported-by: syzbot+cd24df4d075c319ebfc5@syzkaller.appspotmail.com
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/usb/class/usblp.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
index fb8bd60c83f4..0d8e3f3804a3 100644
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c
@@ -445,6 +445,7 @@ static void usblp_cleanup(struct usblp *usblp)
kfree(usblp->readbuf);
kfree(usblp->device_id_string);
kfree(usblp->statusbuf);
+ usb_put_intf(usblp->intf);
kfree(usblp);
}
@@ -1113,7 +1114,7 @@ static int usblp_probe(struct usb_interface *intf,
init_waitqueue_head(&usblp->wwait);
init_usb_anchor(&usblp->urbs);
usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
- usblp->intf = intf;
+ usblp->intf = usb_get_intf(intf);
/* Malloc device ID string buffer to the largest expected length,
* since we can re-query it on an ioctl and a dynamic string
@@ -1198,6 +1199,7 @@ static int usblp_probe(struct usb_interface *intf,
kfree(usblp->readbuf);
kfree(usblp->statusbuf);
kfree(usblp->device_id_string);
+ usb_put_intf(usblp->intf);
kfree(usblp);
abort_ret:
return retval;
--
2.23.0
prev parent reply other threads:[~2019-10-15 17:55 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-15 15:51 KASAN: use-after-free Read in usb_autopm_put_interface syzbot
2019-10-15 17:55 ` Johan Hovold [this message]
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