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authorWilliam Wu <william.wu@rock-chips.com>2017-04-25 17:45:48 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-06-29 12:48:53 +0200
commit889caad4fbe49e3a612ccb971e40c50912f90ace (patch)
treea165558f63a4b1f8ca74975cdb5953a368ece318
parentdb7130d63fd80256d448686a06a5154a8b9b4f62 (diff)
downloadlinux-linaro-stable-889caad4fbe49e3a612ccb971e40c50912f90ace.tar.gz
usb: gadget: f_fs: avoid out of bounds access on comp_desc
commit b7f73850bb4fac1e2209a4dd5e636d39be92f42c upstream. Companion descriptor is only used for SuperSpeed endpoints, if the endpoints are HighSpeed or FullSpeed, the Companion descriptor will not allocated, so we can only access it if gadget is SuperSpeed. I can reproduce this issue on Rockchip platform rk3368 SoC which supports USB 2.0, and use functionfs for ADB. Kernel build with CONFIG_KASAN=y and CONFIG_SLUB_DEBUG=y report the following BUG: ================================================================== BUG: KASAN: slab-out-of-bounds in ffs_func_set_alt+0x224/0x3a0 at addr ffffffc0601f6509 Read of size 1 by task swapper/0/0 ============================================================================ BUG kmalloc-256 (Not tainted): kasan: bad access detected ---------------------------------------------------------------------------- Disabling lock debugging due to kernel taint INFO: Allocated in ffs_func_bind+0x52c/0x99c age=1275 cpu=0 pid=1 alloc_debug_processing+0x128/0x17c ___slab_alloc.constprop.58+0x50c/0x610 __slab_alloc.isra.55.constprop.57+0x24/0x34 __kmalloc+0xe0/0x250 ffs_func_bind+0x52c/0x99c usb_add_function+0xd8/0x1d4 configfs_composite_bind+0x48c/0x570 udc_bind_to_driver+0x6c/0x170 usb_udc_attach_driver+0xa4/0xd0 gadget_dev_desc_UDC_store+0xcc/0x118 configfs_write_file+0x1a0/0x1f8 __vfs_write+0x64/0x174 vfs_write+0xe4/0x200 SyS_write+0x68/0xc8 el0_svc_naked+0x24/0x28 INFO: Freed in inode_doinit_with_dentry+0x3f0/0x7c4 age=1275 cpu=7 pid=247 ... Call trace: [<ffffff900808aab4>] dump_backtrace+0x0/0x230 [<ffffff900808acf8>] show_stack+0x14/0x1c [<ffffff90084ad420>] dump_stack+0xa0/0xc8 [<ffffff90082157cc>] print_trailer+0x188/0x198 [<ffffff9008215948>] object_err+0x3c/0x4c [<ffffff900821b5ac>] kasan_report+0x324/0x4dc [<ffffff900821aa38>] __asan_load1+0x24/0x50 [<ffffff90089eb750>] ffs_func_set_alt+0x224/0x3a0 [<ffffff90089d3760>] composite_setup+0xdcc/0x1ac8 [<ffffff90089d7394>] android_setup+0x124/0x1a0 [<ffffff90089acd18>] _setup+0x54/0x74 [<ffffff90089b6b98>] handle_ep0+0x3288/0x4390 [<ffffff90089b9b44>] dwc_otg_pcd_handle_out_ep_intr+0x14dc/0x2ae4 [<ffffff90089be85c>] dwc_otg_pcd_handle_intr+0x1ec/0x298 [<ffffff90089ad680>] dwc_otg_pcd_irq+0x10/0x20 [<ffffff9008116328>] handle_irq_event_percpu+0x124/0x3ac [<ffffff9008116610>] handle_irq_event+0x60/0xa0 [<ffffff900811af30>] handle_fasteoi_irq+0x10c/0x1d4 [<ffffff9008115568>] generic_handle_irq+0x30/0x40 [<ffffff90081159b4>] __handle_domain_irq+0xac/0xdc [<ffffff9008080e9c>] gic_handle_irq+0x64/0xa4 ... Memory state around the buggy address: ffffffc0601f6400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffffc0601f6480: 00 00 00 00 00 00 00 00 00 00 06 fc fc fc fc fc >ffffffc0601f6500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffffffc0601f6580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffffffc0601f6600: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ================================================================== Signed-off-by: William Wu <william.wu@rock-chips.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Cc: Jerry Zhang <zhangjerry@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/gadget/function/f_fs.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 9ad5145d3103..6d8f865a2fb7 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1668,12 +1668,12 @@ static int ffs_func_eps_enable(struct ffs_function *func)
ep->ep->driver_data = ep;
ep->ep->desc = ds;
- comp_desc = (struct usb_ss_ep_comp_descriptor *)(ds +
- USB_DT_ENDPOINT_SIZE);
- ep->ep->maxburst = comp_desc->bMaxBurst + 1;
-
- if (needs_comp_desc)
+ if (needs_comp_desc) {
+ comp_desc = (struct usb_ss_ep_comp_descriptor *)(ds +
+ USB_DT_ENDPOINT_SIZE);
+ ep->ep->maxburst = comp_desc->bMaxBurst + 1;
ep->ep->comp_desc = comp_desc;
+ }
ret = usb_ep_enable(ep->ep);
if (likely(!ret)) {