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authorBjørn Mork <bjorn@mork.no>2017-08-08 18:02:11 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-08-12 19:34:27 -0700
commit4c345783892eed49702acd9f7e2b48fbce6869c1 (patch)
tree8b2a08e41b07b363b5ba6cf0f10c3460a3a752b0
parent70165c27891e1483dff31bed4b84d19907515655 (diff)
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qmi_wwan: fix NULL deref on disconnect
[ Upstream commit bbae08e592706dc32e5c7c97827b13c1c178668b ] qmi_wwan_disconnect is called twice when disconnecting devices with separate control and data interfaces. The first invocation will set the interface data to NULL for both interfaces to flag that the disconnect has been handled. But the matching NULL check was left out when qmi_wwan_disconnect was added, resulting in this oops: usb 2-1.4: USB disconnect, device number 4 qmi_wwan 2-1.4:1.6 wwp0s29u1u4i6: unregister 'qmi_wwan' usb-0000:00:1d.0-1.4, WWAN/QMI device BUG: unable to handle kernel NULL pointer dereference at 00000000000000e0 IP: qmi_wwan_disconnect+0x25/0xc0 [qmi_wwan] PGD 0 P4D 0 Oops: 0000 [#1] SMP Modules linked in: <stripped irrelevant module list> CPU: 2 PID: 33 Comm: kworker/2:1 Tainted: G E 4.12.3-nr44-normandy-r1500619820+ #1 Hardware name: LENOVO 4291LR7/4291LR7, BIOS CBET4000 4.6-810-g50522254fb 07/21/2017 Workqueue: usb_hub_wq hub_event [usbcore] task: ffff8c882b716040 task.stack: ffffb8e800d84000 RIP: 0010:qmi_wwan_disconnect+0x25/0xc0 [qmi_wwan] RSP: 0018:ffffb8e800d87b38 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffff8c8824f3f1d0 RDI: ffff8c8824ef6400 RBP: ffff8c8824ef6400 R08: 0000000000000000 R09: 0000000000000000 R10: ffffb8e800d87780 R11: 0000000000000011 R12: ffffffffc07ea0e8 R13: ffff8c8824e2e000 R14: ffff8c8824e2e098 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8c8835300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000e0 CR3: 0000000229ca5000 CR4: 00000000000406e0 Call Trace: ? usb_unbind_interface+0x71/0x270 [usbcore] ? device_release_driver_internal+0x154/0x210 ? qmi_wwan_unbind+0x6d/0xc0 [qmi_wwan] ? usbnet_disconnect+0x6c/0xf0 [usbnet] ? qmi_wwan_disconnect+0x87/0xc0 [qmi_wwan] ? usb_unbind_interface+0x71/0x270 [usbcore] ? device_release_driver_internal+0x154/0x210 Reported-and-tested-by: Nathaniel Roach <nroach44@gmail.com> Fixes: c6adf77953bc ("net: usb: qmi_wwan: add qmap mux protocol support") Cc: Daniele Palmas <dnlplm@gmail.com> Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/usb/qmi_wwan.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index 32a22f4e8356..c42153a985be 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -1340,10 +1340,14 @@ static int qmi_wwan_probe(struct usb_interface *intf,
static void qmi_wwan_disconnect(struct usb_interface *intf)
{
struct usbnet *dev = usb_get_intfdata(intf);
- struct qmi_wwan_state *info = (void *)&dev->data;
+ struct qmi_wwan_state *info;
struct list_head *iter;
struct net_device *ldev;
+ /* called twice if separate control and data intf */
+ if (!dev)
+ return;
+ info = (void *)&dev->data;
if (info->flags & QMI_WWAN_FLAG_MUX) {
if (!rtnl_trylock()) {
restart_syscall();