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Message-ID: <87f74eab-ae51-08a4-5b7e-261f437146f4@basealt.ru>
Date: Mon, 29 Jan 2024 21:33:59 +0300
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Subject: Re: [PATCH 5.10.y 0/1] bpf: fix warning ftrace_verify_code
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To: Greg KH <greg@kroah.com>
Cc: stable@vger.kernel.org, linux-kernel@vger.kernel.org,
 bpf@vger.kernel.org, netdev@vger.kernel.org, kpsingh@kernel.org,
 john.fastabend@gmail.com, yhs@fb.com, songliubraving@fb.com, kafai@fb.com,
 andrii@kernel.org, daniel@iogearbox.net, ast@kernel.org,
 nickel@altlinux.org, oficerovas@altlinux.org, dutyrok@altlinux.org
References: <20240129091746.260538-1-kovalev@altlinux.org>
 <2024012954-disfigure-barbell-21b9@gregkh>
From: kovalev@altlinux.org
In-Reply-To: <2024012954-disfigure-barbell-21b9@gregkh>
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29.01.2024 19:20, Greg KH wrote:
> On Mon, Jan 29, 2024 at 12:17:45PM +0300, kovalev@altlinux.org wrote:
>> Syzkaller hit 'WARNING in ftrace_verify_code' bug.
>>
>> This bug is not a vulnerability and is reproduced only when running
>> with root privileges on stable 5.10 kernel.
> What about 5.15.y?  We can't take a patch for older kernels and not for
> newer ones, right?

Indeed, this patch was not backported at 5.15.

I fixed it, successfully tested it on the 5.15.148 kernel and sent the 
patch [1]

However, at the time of the kernel build, I noticed a compiler warning 
about an unused "*tmp" variable,

that I fixed in the patch for 5.15, but remained in this patch 5.10:

..

+	void *new, *tmp;
..
need to fix on
..
+	void *new;
..

Therefore, I resend the patch with a fix (deleted the unused tmp 
pointer). [2]

[1] 
https://lore.kernel.org/bpf/20240129180108.284057-1-kovalev@altlinux.org/T/#u

[2] 
https://lore.kernel.org/bpf/20240129183120.284801-1-kovalev@altlinux.org/T/#u

-- 

Regards,
Vasiliy Kovalev