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Message-ID: <6fbd0c06-0e1a-d2a9-cfdf-c953e559fec1@alu.unizg.hr>
Date:   Mon, 3 Jul 2023 07:18:34 +0200
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From:   Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Subject: Re: [CRASH][BISECTED] 6.4.1 crash in boot
To:     Guenter Roeck <linux@roeck-us.net>,
        Kees Cook <keescook@chromium.org>,
        Bagas Sanjaya <bagasdotme@gmail.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux LLVM <llvm@lists.linux.dev>,
        linux-kbuild@vger.kernel.org,
        Linux Regressions <regressions@lists.linux.dev>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>
References: <9a8e34ad-8a8b-3830-4878-3c2c82e69dd9@alu.unizg.hr>
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 <625e951e-9922-d15d-5520-e8cd5eba1995@roeck-us.net>
 <4fa56264-f188-46f9-cc77-117b469b3328@roeck-us.net>
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On 7/3/23 05:58, Guenter Roeck wrote:
> On 7/2/23 20:26, Guenter Roeck wrote:
>> On 7/2/23 20:20, Kees Cook wrote:
>>> On Mon, Jul 03, 2023 at 08:44:37AM +0700, Bagas Sanjaya wrote:
>>>> On Sun, Jul 02, 2023 at 06:36:12PM +0200, Mirsad Goran Todorovac wrote:
>>>>> Hi,
>>>>>
>>>>> After new git pull the kernel in Torvalds tree with default debug config
>>>>> failed to boot with error that occurs prior to mounting filesystems, so there
>>>>> is no log safe for the screenshot(s) here:
>>>>>
>>>>> [1] https://domac.alu.unizg.hr/~mtodorov/linux/crashes/2023-07-02/
>>>>>
>>>>> Bisect shows the first bad commit is 2d47c6956ab3 (v6.4-rc2-1-g2d47c6956ab3):
>>>>>
>>>>> # good: [98be618ad03010b1173fc3c35f6cbb4447ee2b07] Merge tag 'Smack-for-6.5' of https://github.com/cschaufler/smack-next
>>>>> git bisect good 98be618ad03010b1173fc3c35f6cbb4447ee2b07
>>>>> # bad: [f4a0659f823e5a828ea2f45b4849ea8e2dd2984c] drm/i2c: tda998x: Replace all non-returning strlcpy with strscpy
>>>>> git bisect bad f4a0659f823e5a828ea2f45b4849ea8e2dd2984c
>>>>> .
>>>>> .
>>>>> .
>>>>> # bad: [2d47c6956ab3c8b580a59d7704aab3e2a4882b6c] ubsan: Tighten UBSAN_BOUNDS on GCC
>>>>> git bisect bad 2d47c6956ab3c8b580a59d7704aab3e2a4882b6c
>>>>> # first bad commit: [2d47c6956ab3c8b580a59d7704aab3e2a4882b6c] ubsan: Tighten UBSAN_BOUNDS on GCC
>>>>>
>>>>> The architecture is Ubuntu 22.04 with lshw and config give in the attachment.
>>>>
>>>> Can you show early kernel log (something like dmesg)?
>>>>
>>>> Anyway, I'm adding it to regzbot:
>>>>
>>>> #regzbot ^introduced: 2d47c6956ab3c8
>>>> #regzbot title: Linux kernel fails to boot due to UBSAN_BOUNDS tightening
>>>
>>> I'm confused. Commit 2d47c6956ab3c8b580a59d7704aab3e2a4882b6c isn't in the v6.4
>>> tree... it's only in Linus's ToT.
>>>
>>
>> In ToT:
>>
>> $ git describe 2d47c6956ab3
>> v6.4-rc2-1-g2d47c6956ab3
>>
>> $ git describe --contains 2d47c6956ab3
>> next-20230616~2^2~51
>> $ git describe --contains --match 'v*' 2d47c6956ab3
>> fatal: cannot describe '2d47c6956ab3c8b580a59d7704aab3e2a4882b6c'
>>
>> "git describe" always shows the parent tree, which I guess was based on
>> v6.4-rc2.
>>
> 
> Ah, sorry, I didn't realize that the subject claims that the problem
> would be in 6.4.1. That indeed does not match the bisect results.

I apologise for confusion. In fact, I have cloned the Torvalds tree after
6.4.1 was released, but I actually cloned the Torvalds tree, not the 6.4.1
from the stable branch as the Subject line might have misled.

But I think the text explained that the Torvalds tree was cloned
and the method:

] After new git pull the kernel in Torvalds tree with default debug config
] failed to boot with error that occurs prior to mounting filesystems, so there
] is no log safe for the screenshot(s) here:

I will try to be more consistent and precise the next time.

Sorry again for the confusion.

I am right now cloning directly from the Torvalds tree for the third time
and with the Ubuntu generic production kernel and the result is the same:
crash in boot for 2d47c6956ab3.

Best regards,
Mirsad Todorovac