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Message-ID: <9bf36e3a-f718-ec96-3759-e8f17fe025f3@gmail.com>
Date:   Mon, 17 Oct 2022 11:20:24 +0700
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Subject: Re: 6.1rc1: NFS memcpy warning on mount
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To:     Kees Cook <keescook@chromium.org>
Cc:     Dave Jones <davej@codemonkey.org.uk>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-nfs@vger.kernel.org, linux-hardening@vger.kernel.org,
        Trond Myklebust <trond.myklebust@hammerspace.com>,
        Scott Mayhew <smayhew@redhat.com>,
        Anna Schumaker <anna@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
References: <CAHk-=wj6y5fipM2A5kEuOO9qm5PBzUY=-m9viEahhtxT09KR_g@mail.gmail.com>
 <Y0zEzZwhOxTDcBTB@codemonkey.org.uk> <Y0zS/5WLi2q4Ua2U@debian.me>
 <202210162113.1A948FEAB@keescook>
From:   Bagas Sanjaya <bagasdotme@gmail.com>
In-Reply-To: <202210162113.1A948FEAB@keescook>
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On 10/17/22 11:17, Kees Cook wrote:
> On Mon, Oct 17, 2022 at 10:58:55AM +0700, Bagas Sanjaya wrote:
>> On Sun, Oct 16, 2022 at 10:58:21PM -0400, Dave Jones wrote:
>>> Started getting this during mount on a 6.1rc1 kernel..
>>> not sure which mount it's complaining about, but they're all v3 tcp
>>> mounts on that machine.
>>>
>>> [   19.617475] memcpy: detected field-spanning write (size 28) of single field "request.sap" at fs/nfs/super.c:857 (size 18446744073709551615)
>> [...]
>> Hmm, the blamed line in the warning is introduced by 38465f5d1af932 ("NFS:
>> rename nfs_fs_context pointer arg in a few functions"). Cc: the commit
>> author. Also Cc: Kees for authoring the patch [1] that have fixed
>> similar warning.
> 
> The warning is from commit 54d9469bc515 ("fortify: Add run-time WARN
> for cross-field memcpy()")
> 
>> Also, does v6.0 have this warning? If so, you need to bisect in the range
>> of v6.0..v6.1-rc1.
> 
> No need for bisection -- this is almost certainly a false positive (as
> detailed in the above commit: we're working on purging all of these
> cases from the kernel).
> 
>> [1]: https://lore.kernel.org/lkml/20221011065243.583650-1-keescook@chromium.org/
> 
> Yeah, I have a v2 of this patch, which should also fix this request.sap
> issue. Sending shortly...
> 

OK, thanks!

-- 
An old man doll... just what I always wanted! - Clara