Re: WARNING: bad usercopy in hidraw_ioctl

[Andrey Konovalov]

On Thu, Aug 22, 2019 at 12:38 AM syzbot
<syzbot+fc7106c3bcd1cb7b165c@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    eea39f24 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=128c664c600000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=d0c62209eedfd54e
> dashboard link: https://syzkaller.appspot.com/bug?extid=fc7106c3bcd1cb7b165c
> 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+fc7106c3bcd1cb7b165c@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> ------------[ cut here ]------------
> Bad or missing usercopy whitelist? Kernel memory exposure attempt detected
> from SLUB object 'shmem_inode_cache' (offset 88, size 33)!
> WARNING: CPU: 0 PID: 3101 at mm/usercopy.c:74 usercopy_warn+0xe8/0x110
> mm/usercopy.c:74
> Kernel panic - not syncing: panic_on_warn set ...
> CPU: 0 PID: 3101 Comm: syz-executor.0 Not tainted 5.3.0-rc5+ #28
> 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
>   panic+0x2a3/0x6da kernel/panic.c:219
>   __warn.cold+0x20/0x4a kernel/panic.c:576
>   report_bug+0x262/0x2a0 lib/bug.c:186
>   fixup_bug arch/x86/kernel/traps.c:179 [inline]
>   fixup_bug arch/x86/kernel/traps.c:174 [inline]
>   do_error_trap+0x12b/0x1e0 arch/x86/kernel/traps.c:272
>   do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:291
>   invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
> RIP: 0010:usercopy_warn+0xe8/0x110 mm/usercopy.c:74
> Code: e8 bd f8 d6 ff 49 89 e9 4c 89 e1 48 89 de 41 57 48 c7 c7 40 f5 cd 85
> 41 55 41 56 4c 8b 44 24 20 48 8b 54 24 18 e8 9d de ac ff <0f> 0b 48 83 c4
> 18 e9 45 ff ff ff 48 c7 c5 40 f3 cd 85 49 89 ee 49
> RSP: 0018:ffff8881c5d07be8 EFLAGS: 00010282
> RAX: 0000000000000000 RBX: ffffffff85cdf500 RCX: 0000000000000000
> RDX: 0000000000008303 RSI: ffffffff81288cfd RDI: ffffed1038ba0f6f
> RBP: ffffffff85cc2ca0 R08: ffff8881c79b0000 R09: ffffed103b645d58
> R10: ffffed103b645d57 R11: ffff8881db22eabf R12: ffffffff86a6b0c8
> R13: 0000000000000058 R14: ffffffff85cdf380 R15: 0000000000000021
>   check_heap_object mm/usercopy.c:234 [inline]
>   __check_object_size mm/usercopy.c:280 [inline]
>   __check_object_size+0x327/0x39a mm/usercopy.c:250
>   check_object_size include/linux/thread_info.h:119 [inline]
>   check_copy_size include/linux/thread_info.h:150 [inline]
>   copy_to_user include/linux/uaccess.h:151 [inline]
>   hidraw_ioctl+0x65f/0xae0 drivers/hid/hidraw.c:440
>   vfs_ioctl fs/ioctl.c:46 [inline]
>   file_ioctl fs/ioctl.c:509 [inline]
>   do_vfs_ioctl+0xd2d/0x1330 fs/ioctl.c:696
>   ksys_ioctl+0x9b/0xc0 fs/ioctl.c:713
>   __do_sys_ioctl fs/ioctl.c:720 [inline]
>   __se_sys_ioctl fs/ioctl.c:718 [inline]
>   __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:718
>   do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296
>   entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x459829
> Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7
> 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
> ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007f75e27c6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459829
> RDX: 00000000200000c0 RSI: 0000000080404804 RDI: 0000000000000003
> RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007f75e27c76d4
> R13: 00000000004c21c9 R14: 00000000004d5628 R15: 00000000ffffffff
> Kernel Offset: disabled
> Rebooting in 86400 seconds..
>
>
> ---
> This bug is generated by a bot. It may contain errors.
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> syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxxx
>
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#syz dup: BUG: bad usercopy in hidraw_ioctl