On Wed, Sep 13, 2017 at 4:59 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Wed, 13 Sep 2017, Dmitry Vyukov wrote: > >> On Tue, Sep 12, 2017 at 9:57 PM, Greg Kroah-Hartman >> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: >> > On Tue, Sep 12, 2017 at 08:53:11PM +0200, Andrey Konovalov wrote: >> >> Hi! >> >> >> >> I've got the following crash while fuzzing the kernel with syzkaller. >> >> >> >> On commit 81a84ad3cb5711cec79f4dd53a4ce026b092c432 (Sep 3). >> >> >> >> gadgetfs: bound to dummy_udc driver >> >> usb 1-1: new full-speed USB device number 2 using dummy_hcd >> >> gadgetfs: connected >> >> gadgetfs: disconnected >> >> gadgetfs: connected >> >> usb 1-1: New USB device found, idVendor=0000, idProduct=0000 >> >> usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=203 >> >> usb 1-1: SerialNumber: a >> >> gadgetfs: configuration #7 >> >> usb 1-1: BOGUS urb xfer, pipe 1 != type 3 >> >> ------------[ cut here ]------------ >> >> WARNING: CPU: 0 PID: 3 at drivers/usb/core/urb.c:449 usb_submit_urb+0xf8a/0x11d0 >> >> Modules linked in: >> >> CPU: 0 PID: 3 Comm: kworker/0:0 Not tainted 4.13.0+ #111 >> >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 >> >> Workqueue: usb_hub_wq hub_event >> >> task: ffff88006bdc1a00 task.stack: ffff88006bde8000 >> >> RIP: 0010:usb_submit_urb+0xf8a/0x11d0 drivers/usb/core/urb.c:448 >> >> RSP: 0018:ffff88006bdee3c0 EFLAGS: 00010282 >> >> RAX: 0000000000000029 RBX: ffff8800672a7200 RCX: 0000000000000000 >> >> RDX: 0000000000000029 RSI: ffff88006c815c78 RDI: ffffed000d7bdc6a >> >> RBP: ffff88006bdee4c0 R08: fffffbfff0fe00ff R09: fffffbfff0fe00ff >> >> R10: 0000000000000018 R11: fffffbfff0fe00fe R12: 1ffff1000d7bdc7f >> >> R13: 0000000000000003 R14: 0000000000000001 R15: ffff88006b02cc90 >> >> FS: 0000000000000000(0000) GS:ffff88006c800000(0000) knlGS:0000000000000000 >> >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> >> CR2: 00007fe4daddf000 CR3: 000000006add6000 CR4: 00000000000006f0 >> >> Call Trace: >> >> hwarc_neep_init+0x4ce/0x9c0 drivers/uwb/hwa-rc.c:710 >> >> uwb_rc_add+0x2fb/0x730 drivers/uwb/lc-rc.c:361 >> >> hwarc_probe+0x34e/0x9b0 drivers/uwb/hwa-rc.c:858 >> >> usb_probe_interface+0x351/0x8d0 drivers/usb/core/driver.c:361 >> >> really_probe drivers/base/dd.c:385 >> >> driver_probe_device+0x610/0xa00 drivers/base/dd.c:529 >> >> __device_attach_driver+0x230/0x290 drivers/base/dd.c:625 >> >> bus_for_each_drv+0x15e/0x210 drivers/base/bus.c:463 >> >> __device_attach+0x269/0x3c0 drivers/base/dd.c:682 >> >> device_initial_probe+0x1f/0x30 drivers/base/dd.c:729 >> >> bus_probe_device+0x1da/0x280 drivers/base/bus.c:523 >> >> device_add+0xcf9/0x1640 drivers/base/core.c:1703 >> >> usb_set_configuration+0x1064/0x1890 drivers/usb/core/message.c:1932 >> >> generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174 >> >> usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266 >> >> really_probe drivers/base/dd.c:385 >> >> driver_probe_device+0x610/0xa00 drivers/base/dd.c:529 >> >> __device_attach_driver+0x230/0x290 drivers/base/dd.c:625 >> >> bus_for_each_drv+0x15e/0x210 drivers/base/bus.c:463 >> >> __device_attach+0x269/0x3c0 drivers/base/dd.c:682 >> >> device_initial_probe+0x1f/0x30 drivers/base/dd.c:729 >> >> bus_probe_device+0x1da/0x280 drivers/base/bus.c:523 >> >> device_add+0xcf9/0x1640 drivers/base/core.c:1703 >> >> usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457 >> >> hub_port_connect drivers/usb/core/hub.c:4890 >> >> hub_port_connect_change drivers/usb/core/hub.c:4996 >> >> port_event drivers/usb/core/hub.c:5102 >> >> hub_event+0x23c8/0x37c0 drivers/usb/core/hub.c:5182 >> >> process_one_work+0x9fb/0x1570 kernel/workqueue.c:2097 >> >> worker_thread+0x1e4/0x1350 kernel/workqueue.c:2231 >> >> kthread+0x324/0x3f0 kernel/kthread.c:231 >> >> ret_from_fork+0x25/0x30 arch/x86/entry/entry_64.S:425 >> >> Code: 48 8b 85 30 ff ff ff 48 8d b8 98 00 00 00 e8 8e 93 07 ff 45 89 >> >> e8 44 89 f1 4c 89 fa 48 89 c6 48 c7 c7 a0 e5 55 86 e8 20 08 8f fd <0f> >> >> ff e9 9b f7 ff ff e8 4a 04 d6 fd e9 80 f7 ff ff e8 60 11 a6 >> >> ---[ end trace 55d741234124cfc3 ]--- >> > >> > It's a WARN_ON(), here, not really a "problem", right? You are trying >> > to fuzz the drivers by giving it crappy descriptors, and you triggered a >> > valid warning from the kernel notifying you that your "hardware" is >> > really an invalid USB device :) >> > >> > So nothing to really "fix" here, this is "working as expected", right? >> >> >> WARNING means bug in kernel source code that kernel can tolerate (as >> opposed to BUG). >> Invalid inputs to kernel should not trigger WARNINGs nor BUGs. The >> stack is pointless here, the registers are pointless, what's relevant >> here is: >> >> usb 1-1: BOGUS urb xfer, pipe 1 != type 3 >> >> And this looks like enough information (can be extended if there are >> some other relevant values). >> WARNINGs on invalid inputs cause local DoS, does not allow any testing >> automation and cause spam for kernel developers (what do you do when >> you see WARNING/BUG on console in a subsystem that you are not aware >> of? right, you notify maintainers). >> >> So, if it's just an invalid input to kernel, the action point here is >> to change it to pr_err/pr_warn/dev_printk. > > The message indicates that the driver has called usb_submit_urb() after > setting up the URB with usb_fill_int_urb(), but the endpoint descriptor > says that the endpoint is bulk, not interrupt. > > Either the driver should detect that the endpoint has the wrong type > and refuse to use it, or else it should allow for the possibility by > calling usb_fill_bulk_urb() when necessary. I've mailed a patch that takes the first approach. https://patchwork.kernel.org/patch/9953267/ > > Without knowing the specs for the device in question, I can't say which > alternative would be better. > > Alan Stern > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
