7b2db29fbb
If usb_get_bos_descriptor() returns an error, usb->bos will be NULL. Nevertheless, it is dereferenced unconditionally in hub_set_initial_usb2_lpm_policy() if usb2_hw_lpm_capable is set. This results in a crash. usb 5-1: unable to get BOS descriptor ... Unable to handle kernel NULL pointer dereference at virtual address 00000008 pgd = ffffffc00165f000 [00000008] *pgd=000000000174f003, *pud=000000000174f003, *pmd=0000000001750003, *pte=00e8000001751713 Internal error: Oops: 96000005 [#1] PREEMPT SMP Modules linked in: uinput uvcvideo videobuf2_vmalloc cmac [ ... ] CPU: 5 PID: 3353 Comm: kworker/5:3 Tainted: G B 4.4.52 #480 Hardware name: Google Kevin (DT) Workqueue: events driver_set_config_work task: ffffffc0c3690000 ti: ffffffc0ae9a8000 task.ti: ffffffc0ae9a8000 PC is at hub_port_init+0xc3c/0xd10 LR is at hub_port_init+0xc3c/0xd10 ... Call trace: [<ffffffc0007fbbfc>] hub_port_init+0xc3c/0xd10 [<ffffffc0007fbe2c>] usb_reset_and_verify_device+0x15c/0x82c [<ffffffc0007fc5e0>] usb_reset_device+0xe4/0x298 [<ffffffbffc0e3fcc>] rtl8152_probe+0x84/0x9b0 [r8152] [<ffffffc00080ca8c>] usb_probe_interface+0x244/0x2f8 [<ffffffc000774a24>] driver_probe_device+0x180/0x3b4 [<ffffffc000774e48>] __device_attach_driver+0xb4/0xe0 [<ffffffc000772168>] bus_for_each_drv+0xb4/0xe4 [<ffffffc0007747ec>] __device_attach+0xd0/0x158 [<ffffffc000775080>] device_initial_probe+0x24/0x30 [<ffffffc0007739d4>] bus_probe_device+0x50/0xe4 [<ffffffc000770bd0>] device_add+0x414/0x738 [<ffffffc000809fe8>] usb_set_configuration+0x89c/0x914 [<ffffffc00080a120>] driver_set_config_work+0xc0/0xf0 [<ffffffc000249bb8>] process_one_work+0x390/0x6b8 [<ffffffc00024abcc>] worker_thread+0x480/0x610 [<ffffffc000251a80>] kthread+0x164/0x178 [<ffffffc0002045d0>] ret_from_fork+0x10/0x40 Since we don't know anything about LPM capabilities without BOS descriptor, don't attempt to enable LPM if it is not available. Fixes: 890dae886721 ("xhci: Enable LPM support only for hardwired ...") Cc: stable <stable@vger.kernel.org> Cc: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.