Re: Re: KASAN: use-after-free Read in wdm_out_callback

[syzbot]

> On Mon, Aug 19, 2019 at 4:48 PM syzbot
> <syzbot+9a22af9cbb07280ce9cf@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

> > Hello,

> > syzbot found the following crash on:

> > HEAD commit:    d0847550 usb-fuzzer: main usb gadget fuzzer driver
> > git tree:       https://github.com/google/kasan.git usb-fuzzer
> > console output: https://syzkaller.appspot.com/x/log.txt?x=136553ba600000
> > kernel config:   
> > https://syzkaller.appspot.com/x/.config?x=dbc9c80cc095da19
> > dashboard link:  
> > https://syzkaller.appspot.com/bug?extid=9a22af9cbb07280ce9cf
> > compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

> > Unfortunately, I don't have any reproducer for this crash yet.

> > IMPORTANT: if you fix the bug, please add the following tag to the  
> > commit:
> > Reported-by: syzbot+9a22af9cbb07280ce9cf@xxxxxxxxxxxxxxxxxxxxxxxxx

> > cdc_wdm 1-1:118.0: nonzero urb status received: -71
> > cdc_wdm 1-1:118.0: wdm_int_callback - 0 bytes
> > ==================================================================
> > BUG: KASAN: use-after-free in __lock_acquire+0x302a/0x3b50
> > kernel/locking/lockdep.c:3753
> > Read of size 8 at addr ffff8881cbdca8e8 by task swapper/0/0

> > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-rc4+ #26
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> > Google 01/01/2011
> > Call Trace:
> >    <IRQ>
> >    __dump_stack lib/dump_stack.c:77 [inline]
> >    dump_stack+0xca/0x13e lib/dump_stack.c:113
> >    print_address_description+0x6a/0x32c mm/kasan/report.c:351
> >    __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482
> >    kasan_report+0xe/0x12 mm/kasan/common.c:612
> >    __lock_acquire+0x302a/0x3b50 kernel/locking/lockdep.c:3753
> >    lock_acquire+0x127/0x320 kernel/locking/lockdep.c:4412
> >    __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
> >    _raw_spin_lock_irqsave+0x32/0x50 kernel/locking/spinlock.c:159
> >    wdm_out_callback+0x45/0x170 drivers/usb/class/cdc-wdm.c:148
> >    __usb_hcd_giveback_urb+0x1f2/0x470 drivers/usb/core/hcd.c:1657
> >    usb_hcd_giveback_urb+0x368/0x420 drivers/usb/core/hcd.c:1722
> >    dummy_timer+0x120f/0x2fa2 drivers/usb/gadget/udc/dummy_hcd.c:1965
> >    call_timer_fn+0x179/0x650 kernel/time/timer.c:1322
> >    expire_timers kernel/time/timer.c:1366 [inline]
> >    __run_timers kernel/time/timer.c:1685 [inline]
> >    __run_timers kernel/time/timer.c:1653 [inline]
> >    run_timer_softirq+0x5cc/0x14b0 kernel/time/timer.c:1698
> >    __do_softirq+0x221/0x912 kernel/softirq.c:292
> >    invoke_softirq kernel/softirq.c:373 [inline]
> >    irq_exit+0x178/0x1a0 kernel/softirq.c:413
> >    exiting_irq arch/x86/include/asm/apic.h:537 [inline]
> >    smp_apic_timer_interrupt+0x12f/0x500 arch/x86/kernel/apic/apic.c:1095
> >    apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
> >    </IRQ>
> > RIP: 0010:default_idle+0x28/0x2e0 arch/x86/kernel/process.c:581
> > Code: 90 90 41 56 41 55 65 44 8b 2d 64 ea 93 7a 41 54 55 53 0f 1f 44 00  
> > 00
> > e8 96 5b d5 fb e9 07 00 00 00 0f 00 2d 7a 8f 54 00 fb f4 <65> 44 8b 2d 40
> > ea 93 7a 0f 1f 44 00 00 5b 5d 41 5c 41 5d 41 5e c3
> > RSP: 0018:ffffffff86c07da8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
> > RAX: 0000000000000007 RBX: ffffffff86c2b200 RCX: 0000000000000000
> > RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffffffff86c2ba44
> > RBP: fffffbfff0d85640 R08: ffffffff86c2b200 R09: 0000000000000000
> > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
> >    cpuidle_idle_call kernel/sched/idle.c:154 [inline]
> >    do_idle+0x3c2/0x4f0 kernel/sched/idle.c:263
> >    cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:354
> >    start_kernel+0x838/0x872 init/main.c:785
> >    secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241

> > Allocated by task 83:
> >    save_stack+0x1b/0x80 mm/kasan/common.c:69
> >    set_track mm/kasan/common.c:77 [inline]
> >    __kasan_kmalloc mm/kasan/common.c:487 [inline]
> >    __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:460
> >    kmalloc include/linux/slab.h:552 [inline]
> >    kzalloc include/linux/slab.h:748 [inline]
> >    wdm_create+0x56/0x1720 drivers/usb/class/cdc-wdm.c:786
> >    wdm_probe+0x220/0x2d0 drivers/usb/class/cdc-wdm.c:922
> >    usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
> >    really_probe+0x281/0x6d0 drivers/base/dd.c:548
> >    driver_probe_device+0x101/0x1b0 drivers/base/dd.c:721
> >    __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
> >    bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:454
> >    __device_attach+0x217/0x360 drivers/base/dd.c:894
> >    bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
> >    device_add+0xae6/0x16f0 drivers/base/core.c:2165
> >    usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
> >    generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
> >    usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
> >    really_probe+0x281/0x6d0 drivers/base/dd.c:548
> >    driver_probe_device+0x101/0x1b0 drivers/base/dd.c:721
> >    __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
> >    bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:454
> >    __device_attach+0x217/0x360 drivers/base/dd.c:894
> >    bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
> >    device_add+0xae6/0x16f0 drivers/base/core.c:2165
> >    usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536
> >    hub_port_connect drivers/usb/core/hub.c:5098 [inline]
> >    hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
> >    port_event drivers/usb/core/hub.c:5359 [inline]
> >    hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441
> >    process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
> >    worker_thread+0x96/0xe20 kernel/workqueue.c:2415
> >    kthread+0x318/0x420 kernel/kthread.c:255
> >    ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

> > Freed by task 83:
> >    save_stack+0x1b/0x80 mm/kasan/common.c:69
> >    set_track mm/kasan/common.c:77 [inline]
> >    __kasan_slab_free+0x130/0x180 mm/kasan/common.c:449
> >    slab_free_hook mm/slub.c:1423 [inline]
> >    slab_free_freelist_hook mm/slub.c:1474 [inline]
> >    slab_free mm/slub.c:3016 [inline]
> >    kfree+0xe4/0x2f0 mm/slub.c:3957
> >    wdm_create+0x542/0x1720 drivers/usb/class/cdc-wdm.c:884
> >    wdm_probe+0x220/0x2d0 drivers/usb/class/cdc-wdm.c:922
> >    usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
> >    really_probe+0x281/0x6d0 drivers/base/dd.c:548
> >    driver_probe_device+0x101/0x1b0 drivers/base/dd.c:721
> >    __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
> >    bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:454
> >    __device_attach+0x217/0x360 drivers/base/dd.c:894
> >    bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
> >    device_add+0xae6/0x16f0 drivers/base/core.c:2165
> >    usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
> >    generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
> >    usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
> >    really_probe+0x281/0x6d0 drivers/base/dd.c:548
> >    driver_probe_device+0x101/0x1b0 drivers/base/dd.c:721
> >    __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
> >    bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:454
> >    __device_attach+0x217/0x360 drivers/base/dd.c:894
> >    bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
> >    device_add+0xae6/0x16f0 drivers/base/core.c:2165
> >    usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536
> >    hub_port_connect drivers/usb/core/hub.c:5098 [inline]
> >    hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
> >    port_event drivers/usb/core/hub.c:5359 [inline]
> >    hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441
> >    process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
> >    worker_thread+0x96/0xe20 kernel/workqueue.c:2415
> >    kthread+0x318/0x420 kernel/kthread.c:255
> >    ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

> > The buggy address belongs to the object at ffff8881cbdca880
> >    which belongs to the cache kmalloc-1k of size 1024
> > The buggy address is located 104 bytes inside of
> >    1024-byte region [ffff8881cbdca880, ffff8881cbdcac80)
> > The buggy address belongs to the page:
> > page:ffffea00072f7200 refcount:1 mapcount:0 mapping:ffff8881da002280
> > index:0x0 compound_mapcount: 0
> > flags: 0x200000000010200(slab|head)
> > raw: 0200000000010200 ffffea000719ca00 0000000400000004 ffff8881da002280
> > raw: 0000000000000000 00000000000e000e 00000001ffffffff 0000000000000000
> > page dumped because: kasan: bad access detected

> > Memory state around the buggy address:
> >    ffff8881cbdca780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> >    ffff8881cbdca800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> > > ffff8881cbdca880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> >                                                             ^
> >    ffff8881cbdca900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> >    ffff8881cbdca980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ==================================================================


> > ---
> > This bug is generated by a bot. It may contain errors.
> > See https://goo.gl/tpsmEJ for more information about syzbot.
> > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxxx

> > syzbot will keep track of this bug report. See:
> > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

> Most probably the same issue as:

> https://syzkaller.appspot.com/bug?id=07a5f1529b95adcb80cbf8729f9cb499b980991d

> #syz dup: KASAN: use-after-free Read in wdm_out_callback

Can't dup bug to itself.