Re: [syzbot] KASAN: vmalloc-out-of-bounds Read in kvm_dev_ioctl

From: syzbot
Date: Wed Aug 17 2022 - 16:25:01 EST


> On 8/17/22 16:30, syzbot wrote:
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 7ebfc85e2cd7 Merge tag 'net-6.0-rc1' of git://git.kernel.o..
>> git tree: upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=10b66b6b080000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=c15de4ee7650fb42
>> dashboard link: https://syzkaller.appspot.com/bug?extid=8d24abd02cd4eb911bbd
>> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>>
>> Unfortunately, I don't have any reproducer for this issue yet.
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: syzbot+8d24abd02cd4eb911bbd@xxxxxxxxxxxxxxxxxxxxxxxxx
>>
>> ==================================================================
>> BUG: KASAN: vmalloc-out-of-bounds in __list_add_valid+0x93/0xb0 lib/list_debug.c:27
>> Read of size 8 at addr ffffc90006b7a348 by task syz-executor.4/20901
>>
>> CPU: 1 PID: 20901 Comm: syz-executor.4 Not tainted 5.19.0-syzkaller-13930-g7ebfc85e2cd7 #0
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
>> Call Trace:
>> <TASK>
>> __dump_stack lib/dump_stack.c:88 [inline]
>> dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
>> print_address_description mm/kasan/report.c:317 [inline]
>> print_report.cold+0x59/0x6e9 mm/kasan/report.c:433
>> kasan_report+0xb1/0x1e0 mm/kasan/report.c:495
>> __list_add_valid+0x93/0xb0 lib/list_debug.c:27
>> __list_add include/linux/list.h:69 [inline]
>> list_add include/linux/list.h:88 [inline]
>> kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1219 [inline]
>> kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:4910 [inline]
>> kvm_dev_ioctl+0xf44/0x1ce0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4957
>> vfs_ioctl fs/ioctl.c:51 [inline]
>> __do_sys_ioctl fs/ioctl.c:870 [inline]
>> __se_sys_ioctl fs/ioctl.c:856 [inline]
>> __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
>> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>> do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
>> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>> RIP: 0033:0x7fb1fba89279
>> Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
>> RSP: 002b:00007fb1fcc1e168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
>> RAX: ffffffffffffffda RBX: 00007fb1fbb9bf80 RCX: 00007fb1fba89279
>> RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000004
>> RBP: 00007fb1fbae3189 R08: 0000000000000000 R09: 0000000000000000
>> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
>> R13: 00007ffea48aadbf R14: 00007fb1fcc1e300 R15: 0000000000022000
>> </TASK>
>>
>> Memory state around the buggy address:
>> ffffc90006b7a200: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>> ffffc90006b7a280: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>>> ffffc90006b7a300: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>> ^
>> ffffc90006b7a380: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>> ffffc90006b7a400: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>> ==================================================================
>>
>>
>> ---
>> This report 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@xxxxxxxxxxxxxxxx.
>>
>> syzbot will keep track of this issue. See:
>> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>>
>
> #syz dup: BUG: unable to handle kernel paging request in

can't find the dup bug

> kvm_arch_hardware_enable
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx.
> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/bb50f7ae-0670-fe7d-c7d7-10036aba13f4%40redhat.com.