Re: BUG: bad usercopy in read_rio

[Andrey Konovalov]

On Wed, Oct 9, 2019 at 6:09 PM syzbot
<syzbot+43e923a8937c203e9954@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    58d5f26a 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=149329b3600000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=aa5dac3cda4ffd58
> dashboard link: https://syzkaller.appspot.com/bug?extid=43e923a8937c203e9954
> 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+43e923a8937c203e9954@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> usb 3-1: Rio opened.
> usercopy: Kernel memory exposure attempt detected from wrapped address
> (offset 0, size 18446612689754797056)!
> ------------[ cut here ]------------
> kernel BUG at mm/usercopy.c:99!
> invalid opcode: 0000 [#1] SMP KASAN
> CPU: 0 PID: 12744 Comm: syz-executor.2 Not tainted 5.4.0-rc1+ #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> RIP: 0010:usercopy_abort+0xb9/0xbb mm/usercopy.c:99
> Code: e8 42 55 d6 ff 49 89 d9 4d 89 e8 4c 89 e1 41 56 48 89 ee 48 c7 c7 00
> d8 cd 85 ff 74 24 08 41 57 48 8b 54 24 20 e8 b6 e6 c0 ff <0f> 0b e8 16 55
> d6 ff e8 11 8c fd ff 8b 54 24 04 49 89 d8 4c 89 e1
> RSP: 0018:ffff8881cf06fc60 EFLAGS: 00010282
> RAX: 000000000000006d RBX: ffffffff85cdd520 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: ffffffff8128bf9d RDI: ffffed1039e0df7e
> RBP: ffffffff85cdd6e0 R08: 000000000000006d R09: ffffed103b645d58
> R10: ffffed103b645d57 R11: ffff8881db22eabf R12: ffffffff85cdd880
> R13: ffffffff85cdd520 R14: ffff8881ca0c3400 R15: ffffffff85cdd520
> FS:  00007f3de63a2700(0000) GS:ffff8881db200000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f3de633edb8 CR3: 00000001c9e27000 CR4: 00000000001406f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>   check_bogus_address mm/usercopy.c:152 [inline]
>   __check_object_size mm/usercopy.c:266 [inline]
>   __check_object_size.cold+0xb2/0xbb mm/usercopy.c:256
>   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]
>   read_rio+0x223/0x47c drivers/usb/misc/rio500.c:423
>   __vfs_read+0x76/0x100 fs/read_write.c:425
>   vfs_read+0x1ea/0x430 fs/read_write.c:461
>   ksys_read+0x127/0x250 fs/read_write.c:587
>   do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:290
>   entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x459a59
> 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:00007f3de63a1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
> RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459a59
> RDX: 00000000000000da RSI: 0000000020000140 RDI: 0000000000000004
> RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3de63a26d4
> R13: 00000000004c70d5 R14: 00000000004dc948 R15: 00000000ffffffff
> Modules linked in:
> ---[ end trace 5c4a17213aed3a20 ]---
> RIP: 0010:usercopy_abort+0xb9/0xbb mm/usercopy.c:99
> Code: e8 42 55 d6 ff 49 89 d9 4d 89 e8 4c 89 e1 41 56 48 89 ee 48 c7 c7 00
> d8 cd 85 ff 74 24 08 41 57 48 8b 54 24 20 e8 b6 e6 c0 ff <0f> 0b e8 16 55
> d6 ff e8 11 8c fd ff 8b 54 24 04 49 89 d8 4c 89 e1
> RSP: 0018:ffff8881cf06fc60 EFLAGS: 00010282
> RAX: 000000000000006d RBX: ffffffff85cdd520 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: ffffffff8128bf9d RDI: ffffed1039e0df7e
> RBP: ffffffff85cdd6e0 R08: 000000000000006d R09: ffffed103b645d58
> R10: ffffed103b645d57 R11: ffff8881db22eabf R12: ffffffff85cdd880
> R13: ffffffff85cdd520 R14: ffff8881ca0c3400 R15: ffffffff85cdd520
> FS:  00007f3de63a2700(0000) GS:ffff8881db200000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f3de633edb8 CR3: 00000001c9e27000 CR4: 00000000001406f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>
>
> ---
> 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
>
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#syz fix: USB: rio500: Remove Rio 500 kernel driver