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Date:   Tue, 17 May 2022 00:49:34 +0200
From:   Eugene Syromiatnikov <esyr@redhat.com>
To:     Jiri Olsa <olsajiri@gmail.com>
Cc:     Masami Hiramatsu <mhiramat@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ingo Molnar <mingo@redhat.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>, netdev@vger.kernel.org,
        bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
        Shuah Khan <shuah@kernel.org>, linux-kselftest@vger.kernel.org
Subject: Re: [PATCH bpf 1/4] bpf_trace: check size for overflow in
 bpf_kprobe_multi_link_attach
Message-ID: <20220516224934.GA5013@asgard.redhat.com>
References: <20220516182708.GA29437@asgard.redhat.com>
 <YoLDdaObEQePcIN+@krava>
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On Mon, May 16, 2022 at 11:34:45PM +0200, Jiri Olsa wrote:
> On Mon, May 16, 2022 at 08:27:08PM +0200, Eugene Syromiatnikov wrote:
> > +	if (check_mul_overflow(cnt, sizeof(*syms), &size))
> > +		return -EOVERFLOW;
> 
> there was an update already:
> 
>   0236fec57a15 bpf: Resolve symbols with ftrace_lookup_symbols for kprobe multi link
> 
> so this won't apply anymore, could you please rebase on top of the latest bpf-next/master?

The issue that this specific check has to go in 4.18, as it covers
possible out-of-bounds write, I'm not sure how to handle it, have
a branch where it is merged manually?