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Subject: Re: general protection fault in tomoyo_socket_sendmsg_permission
To:     Shuah Khan <skhan@linuxfoundation.org>,
        Hillf Danton <hdanton@sina.com>,
        syzbot <syzbot+95ce4b142579611ef0a9@syzkaller.appspotmail.com>
Cc:     linux-kernel@vger.kernel.org,
        linux-security-module@vger.kernel.org,
        Andrey Konovalov <andreyknvl@google.com>,
        Valentina Manea <valentina.manea.m@gmail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        syzkaller-bugs@googlegroups.com
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From:   Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Message-ID: <40617d66-1334-13a0-de9b-bd7cc1155ce5@i-love.sakura.ne.jp>
Date:   Sat, 30 Jan 2021 11:25:20 +0900
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On 2021/01/30 6:18, Shuah Khan wrote:
> In this console log:

It seems "this console log" refers to https://syzkaller.appspot.com/x/log.txt?x=10453034500000 .

> 
> 06:57:50 executing program 1:
> socketpair$tipc(0x1e, 0x2, 0x0, &(0x7f00000000c0)={<r0=>0xffffffffffffffff})
> sendmsg$BATADV_CMD_GET_TRANSTABLE_LOCAL(r0, &(0x7f00000002c0)={&(0x7f00000001c0), 0xc, &(0x7f0000000280)={0x0, 0xd001010000000000}}, 0x0)
> 
> [ 1151.090883][T23361] vhci_hcd vhci_hcd.0: pdev(4) rhport(0) sockfd(4)
> [ 1151.097445][T23361] vhci_hcd vhci_hcd.0: devid(0) speed(1) speed_str(low-speed)
> 06:57:50 executing program 0:
> r0 = syz_open_dev$binderN(&(0x7f0000000680)='/dev/binder#\x00', 0x0, 0x0)
> ioctl$BINDER_WRITE_READ(r0, 0xc0306201, &(0x7f0000000cc0)={0x88, 0x0, &(0x7f0000000b80)=[@transaction={0x40406300, {0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}}, @transaction={0x40406300, {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}}], 0x0, 0x0, 0x0})
> 
> [ 1151.164402][T23363] vhci_hcd: connection closed
> [ 1151.167346][  T240] vhci_hcd: stop threads
> 
> 
> [ 1151.178329][T26761] usb 17-1: new low-speed USB device number 2 using vhci_hcd
> 
> 
> SK: Looking at the console log, it looks like while connection is being
>     torn down,

Excuse me, but it looks like (what comes here) while connection is being torn down ?
I'm not familiar with driver code.

> 
> 
> [ 1151.181245][  T240] vhci_hcd: release socket
> 
> 
> Can you share your your test code for this program:
> "executing program 1"

I don't think program 1 is relevant. I think program 4

  06:57:50 executing program 4:
  r0 = socket$tipc(0x1e, 0x2, 0x0)
  syz_usbip_server_init(0x1)
  close_range(r0, 0xffffffffffffffff, 0x0)

which calls syz_usbip_server_init() as with other duplicates is relevant.

> 
> Also your setup? Do you run usbip_host and vhci_hcd both?

Who are you referring to with "you/your" ? I'm not running syzkaller in my setup
and I don't have test code.

I'm just proposing printing more messages in order to confirm the ordering of
events and member values in structures.