3.16.79-rc1 review patch. If anyone has any objections, please let me know.
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From: Sean Young sean@mess.org
commit 699bf94114151aae4dceb2d9dbf1a6312839dcae upstream.
The usb_bulk_urb will kfree'd on disconnect, so ensure the pointer is set to NULL after each free.
stop stream urb killing urb buffer free tm6000: got start feed request tm6000_start_feed tm6000: got start stream request tm6000_start_stream tm6000: pipe reset tm6000: got start feed request tm6000_start_feed tm6000: got start feed request tm6000_start_feed tm6000: got start feed request tm6000_start_feed tm6000: got start feed request tm6000_start_feed tm6000: IR URB failure: status: -71, length 0 xhci_hcd 0000:00:14.0: ERROR unknown event type 37 xhci_hcd 0000:00:14.0: ERROR unknown event type 37 tm6000: error tm6000_urb_received usb 1-2: USB disconnect, device number 5 tm6000: disconnecting tm6000 #0 ================================================================== BUG: KASAN: use-after-free in dvb_fini+0x75/0x140 [tm6000_dvb] Read of size 8 at addr ffff888241044060 by task kworker/2:0/22
CPU: 2 PID: 22 Comm: kworker/2:0 Tainted: G W 5.3.0-rc4+ #1 Hardware name: LENOVO 20KHCTO1WW/20KHCTO1WW, BIOS N23ET65W (1.40 ) 07/02/2019 Workqueue: usb_hub_wq hub_event Call Trace: dump_stack+0x9a/0xf0 print_address_description.cold+0xae/0x34f __kasan_report.cold+0x75/0x93 ? tm6000_fillbuf+0x390/0x3c0 [tm6000_alsa] ? dvb_fini+0x75/0x140 [tm6000_dvb] kasan_report+0xe/0x12 dvb_fini+0x75/0x140 [tm6000_dvb] tm6000_close_extension+0x51/0x80 [tm6000] tm6000_usb_disconnect.cold+0xd4/0x105 [tm6000] usb_unbind_interface+0xe4/0x390 device_release_driver_internal+0x121/0x250 bus_remove_device+0x197/0x260 device_del+0x268/0x550 ? __device_links_no_driver+0xd0/0xd0 ? usb_remove_ep_devs+0x30/0x3b usb_disable_device+0x122/0x400 usb_disconnect+0x153/0x430 hub_event+0x800/0x1e40 ? trace_hardirqs_on_thunk+0x1a/0x20 ? hub_port_debounce+0x1f0/0x1f0 ? retint_kernel+0x10/0x10 ? lock_is_held_type+0xf1/0x130 ? hub_port_debounce+0x1f0/0x1f0 ? process_one_work+0x4ae/0xa00 process_one_work+0x4ba/0xa00 ? pwq_dec_nr_in_flight+0x160/0x160 ? do_raw_spin_lock+0x10a/0x1d0 worker_thread+0x7a/0x5c0 ? process_one_work+0xa00/0xa00 kthread+0x1d5/0x200 ? kthread_create_worker_on_cpu+0xd0/0xd0 ret_from_fork+0x3a/0x50
Allocated by task 2682: save_stack+0x1b/0x80 __kasan_kmalloc.constprop.0+0xc2/0xd0 usb_alloc_urb+0x28/0x60 tm6000_start_feed+0x10a/0x300 [tm6000_dvb] dmx_ts_feed_start_filtering+0x86/0x120 [dvb_core] dvb_dmxdev_start_feed+0x121/0x180 [dvb_core] dvb_dmxdev_filter_start+0xcb/0x540 [dvb_core] dvb_demux_do_ioctl+0x7ed/0x890 [dvb_core] dvb_usercopy+0x97/0x1f0 [dvb_core] dvb_demux_ioctl+0x11/0x20 [dvb_core] do_vfs_ioctl+0x5d8/0x9d0 ksys_ioctl+0x5e/0x90 __x64_sys_ioctl+0x3d/0x50 do_syscall_64+0x74/0xe0 entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 22: save_stack+0x1b/0x80 __kasan_slab_free+0x12c/0x170 kfree+0xfd/0x3a0 xhci_giveback_urb_in_irq+0xfe/0x230 xhci_td_cleanup+0x276/0x340 xhci_irq+0x1129/0x3720 __handle_irq_event_percpu+0x6e/0x420 handle_irq_event_percpu+0x6f/0x100 handle_irq_event+0x55/0x84 handle_edge_irq+0x108/0x3b0 handle_irq+0x2e/0x40 do_IRQ+0x83/0x1a0
Signed-off-by: Sean Young sean@mess.org Signed-off-by: Mauro Carvalho Chehab mchehab+samsung@kernel.org [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/media/usb/tm6000/tm6000-dvb.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/drivers/media/usb/tm6000/tm6000-dvb.c +++ b/drivers/media/usb/tm6000/tm6000-dvb.c @@ -111,6 +111,7 @@ static void tm6000_urb_received(struct u printk(KERN_ERR "tm6000: error %s\n", __func__); kfree(urb->transfer_buffer); usb_free_urb(urb); + dev->dvb->bulk_urb = NULL; } } } @@ -143,6 +144,7 @@ static int tm6000_start_stream(struct tm dvb->bulk_urb->transfer_buffer = kzalloc(size, GFP_KERNEL); if (dvb->bulk_urb->transfer_buffer == NULL) { usb_free_urb(dvb->bulk_urb); + dvb->bulk_urb = NULL; printk(KERN_ERR "tm6000: couldn't allocate transfer buffer!\n"); return -ENOMEM; } @@ -170,6 +172,7 @@ static int tm6000_start_stream(struct tm
kfree(dvb->bulk_urb->transfer_buffer); usb_free_urb(dvb->bulk_urb); + dvb->bulk_urb = NULL; return ret; }