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

[Andrey Konovalov <andreyknvl@google.com>]

On Mon, Aug 19, 2019 at 4:48 PM syzbot
<syzbot+1c7a8a0c02f8b83f3a67@syzkaller.appspotmail.com> 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=11605772600000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=dbc9c80cc095da19
> dashboard link: https://syzkaller.appspot.com/bug?extid=1c7a8a0c02f8b83f3a67
> 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+1c7a8a0c02f8b83f3a67@syzkaller.appspotmail.com
>
> ==================================================================
> BUG: KASAN: use-after-free in iowarrior_callback.cold+0x4f/0x51
> drivers/usb/misc/iowarrior.c:208
> Read of size 8 at addr ffff8881d56b5208 by task udevd/4692
>
> CPU: 1 PID: 4692 Comm: udevd 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
>   iowarrior_callback.cold+0x4f/0x51 drivers/usb/misc/iowarrior.c:208
>   __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:__sanitizer_cov_trace_const_cmp1+0x0/0x20 kernel/kcov.c:247
> Code: 66 2e 0f 1f 84 00 00 00 00 00 48 8b 0c 24 48 89 f2 48 89 fe bf 06 00
> 00 00 e9 2c ff ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 <48> 8b 0c 24 40
> 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 e9 0a ff ff ff
> RSP: 0018:ffff8881c9397b20 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
> RAX: 00000000c9397c01 RBX: ffff8881c9397c00 RCX: ffffffff816a906f
> RDX: 0000000000000000 RSI: 00000000c9397c01 RDI: 0000000000000000
> RBP: 00000000c9397c01 R08: ffff8881b05fc800 R09: ffffed103b0df2a5
> R10: ffffed103b0df2a4 R11: ffff8881d86f9523 R12: ffff8881c9397c08
> R13: ffff8881c9397c38 R14: ffff8881d86f94a0 R15: ffff8881c9397c40
>   unlazy_walk+0x116/0x550 fs/namei.c:675
>   complete_walk+0xc6/0x240 fs/namei.c:788
>   path_parentat.isra.0+0x8c/0x160 fs/namei.c:2366
>   filename_parentat.isra.0+0x19c/0x410 fs/namei.c:2386
>   do_renameat2+0x193/0xbb0 fs/namei.c:4545
>   __do_sys_rename fs/namei.c:4673 [inline]
>   __se_sys_rename fs/namei.c:4671 [inline]
>   __x64_sys_rename+0x5d/0x80 fs/namei.c:4671
>   do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296
>   entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x7fb52199e527
> Code: 32 00 64 83 38 15 74 07 b8 ff ff ff ff 5b c3 48 89 df e8 1c c1 07 00
> 85 c0 75 ed 31 c0 eb d3 90 90 90 90 b8 52 00 00 00 0f 05 <48> 3d 01 f0 ff
> ff 73 01 c3 48 8b 0d e1 f8 32 00 31 d2 48 29 c2 64
> RSP: 002b:00007ffe94095c28 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb52199e527
> RDX: 00007fb521ccfe98 RSI: 00007ffe94095c60 RDI: 00007ffe94096060
> RBP: 000000000127daa0 R08: 00007fb5223117a0 R09: 0000000001278560
> R10: 0000000000000000 R11: 0000000000000246 R12: 000000000127aec0
> R13: 000000000126a250 R14: 00007ffe94095c60 R15: 0000000000000001
>
> Allocated by task 12:
>   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]
>   iowarrior_probe+0x7a/0x10b2 drivers/usb/misc/iowarrior.c:753
>   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 12:
>   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
>   iowarrior_delete drivers/usb/misc/iowarrior.c:246 [inline]
>   iowarrior_probe+0xbb4/0x10b2 drivers/usb/misc/iowarrior.c:852
>   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 ffff8881d56b5180
>   which belongs to the cache kmalloc-512 of size 512
> The buggy address is located 136 bytes inside of
>   512-byte region [ffff8881d56b5180, ffff8881d56b5380)
> The buggy address belongs to the page:
> page:ffffea000755ad00 refcount:1 mapcount:0 mapping:ffff8881da002500
> index:0x0 compound_mapcount: 0
> flags: 0x200000000010200(slab|head)
> raw: 0200000000010200 ffffea000757ad00 0000000300000003 ffff8881da002500
> raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
>   ffff8881d56b5100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>   ffff8881d56b5180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ffff8881d56b5200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>                        ^
>   ffff8881d56b5280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>   ffff8881d56b5300: 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@googlegroups.com.
>
> 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=c59a8f0485cd6634443cdf23cdbf3ea264dd888d

#syz dup: KASAN: use-after-free Read in iowarrior_disconnect