commit 904d88d743b0c94092c5117955eab695df8109e8 upstream.

The syzbot reported

Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xca/0x13e lib/dump_stack.c:113 print_address_description+0x67/0x231 mm/kasan/report.c:188 __kasan_report.cold+0x1a/0x32 mm/kasan/report.c:317 kasan_report+0xe/0x20 mm/kasan/common.c:614 qmi_wwan_probe+0x342/0x360 drivers/net/usb/qmi_wwan.c:1417 usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361 really_probe+0x281/0x660 drivers/base/dd.c:509 driver_probe_device+0x104/0x210 drivers/base/dd.c:670 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:777 bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454

Caused by too many confusing indirections and casts. id->driver_info is a pointer stored in a long. We want the pointer here, not the address of it.

Thanks-to: Hillf Danton hdanton@sina.com Reported-by: syzbot+b68605d7fadd21510de1@syzkaller.appspotmail.com Cc: Kristian Evensen kristian.evensen@gmail.com Fixes: e4bf63482c30 ("qmi_wwan: Add quirk for Quectel dynamic config") Signed-off-by: Bjørn Mork bjorn@mork.no

[Upstream commit did not apply because I shuffled two lines in the backport. The fixes tag for 4.14 is 3a6a5107ceb3.]

Signed-off-by: Kristian Evensen kristian.evensen@gmail.com --- drivers/net/usb/qmi_wwan.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c index c2d6c501d..063daa343 100644 --- a/drivers/net/usb/qmi_wwan.c +++ b/drivers/net/usb/qmi_wwan.c @@ -1395,14 +1395,14 @@ static int qmi_wwan_probe(struct usb_interface *intf, return -ENODEV; }

- info = (void *)&id->driver_info; - /* Several Quectel modems supports dynamic interface configuration, so * we need to match on class/subclass/protocol. These values are * identical for the diagnostic- and QMI-interface, but bNumEndpoints is * different. Ignore the current interface if the number of endpoints * equals the number for the diag interface (two). */ + info = (void *)id->driver_info; + if (info->data & QMI_WWAN_QUIRK_QUECTEL_DYNCFG) { if (desc->bNumEndpoints == 2) return -ENODEV;