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authorRoger Quadros <rogerq@ti.com>2019-08-22 16:40:28 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-11-10 11:27:56 +0100
commit818c96ac80beb8208b84cec0e156ee05ff82caf1 (patch)
tree253ce1641b4c1021b0f9bdae0a4e6996eca2a06c
parentb06f37eaa2b3e99833081a527824ce5aa1f0d8f4 (diff)
usb: gadget: udc: core: Fix segfault if udc_bind_to_driver() for pending driver fails
commit 163be6ff7739b12ff300d77897d340f661821da2 upstream. If a gadget driver is in the pending drivers list, a UDC becomes available and udc_bind_to_driver() fails, then it gets deleted from the pending list. i.e. list_del(&driver->pending) in check_pending_gadget_drivers(). Then if that gadget driver is unregistered, usb_gadget_unregister_driver() does a list_del(&driver->pending) again thus causing a page fault as that list entry has been poisoned by the previous list_del(). Fix this by using list_del_init() instead of list_del() in check_pending_gadget_drivers(). Test case: - Make sure no UDC is available - modprobe g_mass_storage file=wrongfile - Load UDC driver so it becomes available lun0: unable to open backing file: wrongfile - modprobe -r g_mass_storage [ 60.900431] Unable to handle kernel paging request at virtual address dead000000000108 [ 60.908346] Mem abort info: [ 60.911145] ESR = 0x96000044 [ 60.914227] Exception class = DABT (current EL), IL = 32 bits [ 60.920162] SET = 0, FnV = 0 [ 60.923217] EA = 0, S1PTW = 0 [ 60.926354] Data abort info: [ 60.929228] ISV = 0, ISS = 0x00000044 [ 60.933058] CM = 0, WnR = 1 [ 60.936011] [dead000000000108] address between user and kernel address ranges [ 60.943136] Internal error: Oops: 96000044 [#1] PREEMPT SMP [ 60.948691] Modules linked in: g_mass_storage(-) usb_f_mass_storage libcomposite xhci_plat_hcd xhci_hcd usbcore ti_am335x_adc kfifo_buf omap_rng cdns3 rng_core udc_core crc32_ce xfrm_user crct10dif_ce snd_so6 [ 60.993995] Process modprobe (pid: 834, stack limit = 0x00000000c2aebc69) [ 61.000765] CPU: 0 PID: 834 Comm: modprobe Not tainted 4.19.59-01963-g065f42a60499 #92 [ 61.008658] Hardware name: Texas Instruments SoC (DT) [ 61.014472] pstate: 60000005 (nZCv daif -PAN -UAO) [ 61.019253] pc : usb_gadget_unregister_driver+0x7c/0x108 [udc_core] [ 61.025503] lr : usb_gadget_unregister_driver+0x30/0x108 [udc_core] [ 61.031750] sp : ffff00001338fda0 [ 61.035049] x29: ffff00001338fda0 x28: ffff800846d40000 [ 61.040346] x27: 0000000000000000 x26: 0000000000000000 [ 61.045642] x25: 0000000056000000 x24: 0000000000000800 [ 61.050938] x23: ffff000008d7b0d0 x22: ffff0000088b07c8 [ 61.056234] x21: ffff000001100000 x20: ffff000002020260 [ 61.061530] x19: ffff0000010ffd28 x18: 0000000000000000 [ 61.066825] x17: 0000000000000000 x16: 0000000000000000 [ 61.072121] x15: 0000000000000000 x14: 0000000000000000 [ 61.077417] x13: ffff000000000000 x12: ffffffffffffffff [ 61.082712] x11: 0000000000000030 x10: 7f7f7f7f7f7f7f7f [ 61.088008] x9 : fefefefefefefeff x8 : 0000000000000000 [ 61.093304] x7 : ffffffffffffffff x6 : 000000000000ffff [ 61.098599] x5 : 8080000000000000 x4 : 0000000000000000 [ 61.103895] x3 : ffff000001100020 x2 : ffff800846d40000 [ 61.109190] x1 : dead000000000100 x0 : dead000000000200 [ 61.114486] Call trace: [ 61.116922] usb_gadget_unregister_driver+0x7c/0x108 [udc_core] [ 61.122828] usb_composite_unregister+0x10/0x18 [libcomposite] [ 61.128643] msg_cleanup+0x18/0xfce0 [g_mass_storage] [ 61.133682] __arm64_sys_delete_module+0x17c/0x1f0 [ 61.138458] el0_svc_common+0x90/0x158 [ 61.142192] el0_svc_handler+0x2c/0x80 [ 61.145926] el0_svc+0x8/0xc [ 61.148794] Code: eb03003f d10be033 54ffff21 a94d0281 (f9000420) [ 61.154869] ---[ end trace afb22e9b637bd9a7 ]--- Segmentation fault Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Roger Quadros <rogerq@ti.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/gadget/udc/core.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index aa31d36bed00..1a79a9955187 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -1149,7 +1149,7 @@ static int check_pending_gadget_drivers(struct usb_udc *udc)
dev_name(&udc->dev)) == 0) {
ret = udc_bind_to_driver(udc, driver);
if (ret != -EPROBE_DEFER)
- list_del(&driver->pending);
+ list_del_init(&driver->pending);
break;
}