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authorBjørn Mork <bjorn@mork.no>2017-11-06 15:32:18 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-11-21 09:21:18 +0100
commite455048c7ae95633c8778a0282d1ee86f78c5349 (patch)
tree5740f0fb9f74d9f437f2f1caea11e6dd45faa63e /drivers/net/usb/qmi_wwan.c
parentcaeeef8438c30e7d0e43293fcb7beb9f953bb2a9 (diff)
net: qmi_wwan: fix divide by 0 on bad descriptors
commit 7fd078337201cf7468f53c3d9ef81ff78cb6df3b upstream. A CDC Ethernet functional descriptor with wMaxSegmentSize = 0 will cause a divide error in usbnet_probe: divide error: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 0 PID: 24 Comm: kworker/0:1 Not tainted 4.14.0-rc8-44453-g1fdc1a82c34f #56 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: usb_hub_wq hub_event task: ffff88006bef5c00 task.stack: ffff88006bf60000 RIP: 0010:usbnet_update_max_qlen+0x24d/0x390 drivers/net/usb/usbnet.c:355 RSP: 0018:ffff88006bf67508 EFLAGS: 00010246 RAX: 00000000000163c8 RBX: ffff8800621fce40 RCX: ffff8800621fcf34 RDX: 0000000000000000 RSI: ffffffff837ecb7a RDI: ffff8800621fcf34 RBP: ffff88006bf67520 R08: ffff88006bef5c00 R09: ffffed000c43f881 R10: ffffed000c43f880 R11: ffff8800621fc406 R12: 0000000000000003 R13: ffffffff85c71de0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88006ca00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe9c0d6dac CR3: 00000000614f4000 CR4: 00000000000006f0 Call Trace: usbnet_probe+0x18b5/0x2790 drivers/net/usb/usbnet.c:1783 qmi_wwan_probe+0x133/0x220 drivers/net/usb/qmi_wwan.c:1338 usb_probe_interface+0x324/0x940 drivers/usb/core/driver.c:361 really_probe drivers/base/dd.c:413 driver_probe_device+0x522/0x740 drivers/base/dd.c:557 Fix by simply ignoring the bogus descriptor, as it is optional for QMI devices anyway. Fixes: 423ce8caab7e ("net: usb: qmi_wwan: New driver for Huawei QMI based WWAN devices") Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net/usb/qmi_wwan.c')
-rw-r--r--drivers/net/usb/qmi_wwan.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index 958af3b1af7f..e325ca3ad565 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -262,7 +262,7 @@ static int qmi_wwan_bind(struct usbnet *dev, struct usb_interface *intf)
}
/* errors aren't fatal - we can live with the dynamic address */
- if (cdc_ether) {
+ if (cdc_ether && cdc_ether->wMaxSegmentSize) {
dev->hard_mtu = le16_to_cpu(cdc_ether->wMaxSegmentSize);
usbnet_get_ethernet_addr(dev, cdc_ether->iMACAddress);
}