Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752273AbdI0SsV (ORCPT ); Wed, 27 Sep 2017 14:48:21 -0400 Received: from mail-oi0-f46.google.com ([209.85.218.46]:45156 "EHLO mail-oi0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750788AbdI0SsR (ORCPT ); Wed, 27 Sep 2017 14:48:17 -0400 X-Google-Smtp-Source: AOwi7QAwdzgayBRSTpbpJTZa8QwKTRVQ1jHuSWhD8e1/yJxuL6JmFM0B+WZO+Js83WE4H6m8W/OegVXohCJgQqX6vmo= MIME-Version: 1.0 In-Reply-To: <2b7b169ee0fb43b4447c8960cdfabcfe118d2a8b.1506536596.git.arvind.yadav.cs@gmail.com> References: <2b7b169ee0fb43b4447c8960cdfabcfe118d2a8b.1506536596.git.arvind.yadav.cs@gmail.com> From: Andrey Konovalov Date: Wed, 27 Sep 2017 20:48:16 +0200 Message-ID: Subject: Re: [RFT v2] [media] siano: FIX use-after-free in worker_thread To: Arvind Yadav Cc: Mauro Carvalho Chehab , Kostya Serebryany , Dmitry Vyukov , mchehab@s-opensource.com, Javier Martinez Canillas , Sakari Ailus , Laurent Pinchart , linux-media@vger.kernel.org, LKML , syzkaller Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8794 Lines: 189 On Wed, Sep 27, 2017 at 8:32 PM, Arvind Yadav wrote: > Call flush_work() on failure and disconnect. Work initialize and schedule > in smsusb_onresponse(). it should be freed in smsusb_stop_streaming(). > > Signed-off-by: Arvind Yadav Hi Arvind, This patch fixes the issue with flush_work() missing, but exposes another one. smsusb_init_device() initializes urbs and submits them in smsusb_start_streaming(). However if smscore_start_device() fails, smsusb_term_device() frees the urbs by freeing smsusb_device_t. The urbs however still remain submitted, which causes another use-after-free. ================================================================== BUG: KASAN: use-after-free in dummy_timer+0x3076/0x3970 Read of size 4 at addr ffff88006b86b348 by task swapper/1/0 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.14.0-rc2-42664-gaf7d1481b3cb-dirty #292 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 dump_stack+0x292/0x395 lib/dump_stack.c:52 print_address_description+0x78/0x280 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 kasan_report+0x23d/0x350 mm/kasan/report.c:409 __asan_report_load4_noabort+0x19/0x20 mm/kasan/report.c:429 dummy_timer+0x3076/0x3970 drivers/usb/gadget/udc/dummy_hcd.c:1791 call_timer_fn+0x2a2/0x940 kernel/time/timer.c:1281 expire_timers kernel/time/timer.c:1320 __run_timers+0x87f/0xd40 kernel/time/timer.c:1620 run_timer_softirq+0x83/0x140 kernel/time/timer.c:1646 __do_softirq+0x2ee/0xc0f kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 irq_exit+0x171/0x1a0 kernel/softirq.c:405 exiting_irq ./arch/x86/include/asm/apic.h:638 smp_apic_timer_interrupt+0x2b9/0x8d0 arch/x86/kernel/apic/apic.c:1048 apic_timer_interrupt+0x9d/0xb0 RIP: 0010:native_safe_halt+0x6/0x10 ./arch/x86/include/asm/irqflags.h:53 RSP: 0018:ffff88006be87b90 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000020 RBX: 1ffff1000d7d0f76 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88006be6ba64 RBP: ffff88006be87b90 R08: ffffffff813d3301 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1000d7d0f82 R13: ffff88006be87cd0 R14: ffffffff86fc59c8 R15: 0000000000000000 arch_safe_halt ./arch/x86/include/asm/paravirt.h:93 default_idle+0x127/0x690 arch/x86/kernel/process.c:341 arch_cpu_idle+0xf/0x20 arch/x86/kernel/process.c:332 default_idle_call+0x3b/0x60 kernel/sched/idle.c:98 cpuidle_idle_call kernel/sched/idle.c:156 do_idle+0x33a/0x410 kernel/sched/idle.c:246 cpu_startup_entry+0x1d/0x20 kernel/sched/idle.c:351 start_secondary+0x3de/0x500 arch/x86/kernel/smpboot.c:278 secondary_startup_64+0xa5/0xa5 arch/x86/kernel/head_64.S:235 Allocated by task 40: save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x11e/0x2d0 mm/slub.c:2772 kmalloc ./include/linux/slab.h:493 kzalloc ./include/linux/slab.h:666 smsusb_init_device+0xd5/0xd10 drivers/media/usb/siano/smsusb.c:409 smsusb_probe+0x4f5/0xdc0 drivers/media/usb/siano/smsusb.c:573 usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_set_configuration+0x104e/0x1870 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:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457 hub_port_connect drivers/usb/core/hub.c:4903 hub_port_connect_change drivers/usb/core/hub.c:5009 port_event drivers/usb/core/hub.c:5115 hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195 process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119 worker_thread+0x221/0x1850 kernel/workqueue.c:2253 kthread+0x3a1/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 Freed by task 40: save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:524 slab_free_hook mm/slub.c:1390 slab_free_freelist_hook mm/slub.c:1412 slab_free mm/slub.c:2988 kfree+0xf6/0x2f0 mm/slub.c:3919 smsusb_term_device+0xd2/0x130 drivers/media/usb/siano/smsusb.c:365 smsusb_init_device+0xd03/0xd10 drivers/media/usb/siano/smsusb.c:494 smsusb_probe+0x4f5/0xdc0 drivers/media/usb/siano/smsusb.c:573 usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_set_configuration+0x104e/0x1870 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:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457 hub_port_connect drivers/usb/core/hub.c:4903 hub_port_connect_change drivers/usb/core/hub.c:5009 port_event drivers/usb/core/hub.c:5115 hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195 process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119 worker_thread+0x221/0x1850 kernel/workqueue.c:2253 kthread+0x3a1/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 The buggy address belongs to the object at ffff88006b86b300 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 72 bytes inside of 4096-byte region [ffff88006b86b300, ffff88006b86c300) The buggy address belongs to the page: page:ffffea0001ae1a00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x100000000008100(slab|head) raw: 0100000000008100 0000000000000000 0000000000000000 0000000180070007 raw: ffffea0001ae8c00 0000000300000003 ffff88006c402c00 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88006b86b200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88006b86b280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88006b86b300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88006b86b380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88006b86b400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Thanks! > --- > This bug report by Andrey Konovalov "usb/media/smsusb: use-after-free in > worker_thread". > changes in v2 : > call flush_work() in smsusb_stop_streaming(). > > drivers/media/usb/siano/smsusb.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/media/usb/siano/smsusb.c b/drivers/media/usb/siano/smsusb.c > index 8c1f926..8142ba4 100644 > --- a/drivers/media/usb/siano/smsusb.c > +++ b/drivers/media/usb/siano/smsusb.c > @@ -192,6 +192,8 @@ static void smsusb_stop_streaming(struct smsusb_device_t *dev) > for (i = 0; i < MAX_URBS; i++) { > usb_kill_urb(&dev->surbs[i].urb); > > + flush_work(&dev->surbs[i].wq); > + > if (dev->surbs[i].cb) { > smscore_putbuffer(dev->coredev, dev->surbs[i].cb); > dev->surbs[i].cb = NULL; > -- > 2.7.4 >