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

[Andrey Konovalov]

On Mon, Aug 19, 2019 at 4:48 PM syzbot
<syzbot+fa4fa544487e9d02b211@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=14ff4372600000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=dbc9c80cc095da19
> dashboard link: https://syzkaller.appspot.com/bug?extid=fa4fa544487e9d02b211
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16c83b36600000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15cbba22600000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+fa4fa544487e9d02b211@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> ==================================================================
> BUG: KASAN: use-after-free in __mutex_lock_common
> kernel/locking/mutex.c:912 [inline]
> BUG: KASAN: use-after-free in __mutex_lock+0xf23/0x1360
> kernel/locking/mutex.c:1077
> Read of size 8 at addr ffff8881d4a716d8 by task syz-executor812/2337
>
> CPU: 0 PID: 2337 Comm: syz-executor812 Not tainted 5.3.0-rc4+ #26
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Call Trace:
>   __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
>   __mutex_lock_common kernel/locking/mutex.c:912 [inline]
>   __mutex_lock+0xf23/0x1360 kernel/locking/mutex.c:1077
>   iowarrior_release+0x4c/0x280 drivers/usb/misc/iowarrior.c:650
>   __fput+0x2d7/0x840 fs/file_table.c:280
>   task_work_run+0x13f/0x1c0 kernel/task_work.c:113
>   exit_task_work include/linux/task_work.h:22 [inline]
>   do_exit+0x8ef/0x2c00 kernel/exit.c:879
>   do_group_exit+0x125/0x340 kernel/exit.c:983
>   __do_sys_exit_group kernel/exit.c:994 [inline]
>   __se_sys_exit_group kernel/exit.c:992 [inline]
>   __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:992
>   do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296
>   entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x4445f8
> Code: Bad RIP value.
> RSP: 002b:00007ffdf26d4508 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004445f8
> RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
> RBP: 00000000004c4450 R08: 00000000000000e7 R09: ffffffffffffffd4
> R10: 0000000000027c8d R11: 0000000000000246 R12: 0000000000000001
> R13: 00000000006d6180 R14: 0000000000000000 R15: 0000000000000000
>
> Allocated by task 1742:
>   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 1742:
>   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 ffff8881d4a71680
>   which belongs to the cache kmalloc-512 of size 512
> The buggy address is located 88 bytes inside of
>   512-byte region [ffff8881d4a71680, ffff8881d4a71880)
> The buggy address belongs to the page:
> page:ffffea0007529c00 refcount:1 mapcount:0 mapping:ffff8881da002500
> index:0xffff8881d4a70c80 compound_mapcount: 0
> flags: 0x200000000010200(slab|head)
> raw: 0200000000010200 ffffea0007529500 0000000300000003 ffff8881da002500
> raw: ffff8881d4a70c80 00000000800c000a 00000001ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
>   ffff8881d4a71580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>   ffff8881d4a71600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> > ffff8881d4a71680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>                                                      ^
>   ffff8881d4a71700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>   ffff8881d4a71780: 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.
> syzbot can test patches for this bug, for details see:
> https://goo.gl/tpsmEJ#testing-patches

Most probably the same issue as:

https://syzkaller.appspot.com/bug?id=c59a8f0485cd6634443cdf23cdbf3ea264dd888d

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