From: David Laight <david.laight.linux@gmail.com>
To: "Lecomte, Arnaud" <contact@arnaud-lcm.com>
Cc: Brahmajit Das <listout@listout.xyz>,
syzbot+d1b7fa1092def3628bd7@syzkaller.appspotmail.com,
andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org,
daniel@iogearbox.net, eddyz87@gmail.com, haoluo@google.com,
john.fastabend@gmail.com, jolsa@kernel.org, kpsingh@kernel.org,
linux-kernel@vger.kernel.org, martin.lau@linux.dev,
netdev@vger.kernel.org, sdf@fomichev.me, song@kernel.org,
syzkaller-bugs@googlegroups.com, yonghong.song@linux.dev
Subject: Re: [PATCH bpf-next v3] bpf: Clamp trace length in __bpf_get_stack to fix OOB write
Date: Wed, 12 Nov 2025 21:37:39 +0000 [thread overview]
Message-ID: <20251112213739.40123684@pumpkin> (raw)
In-Reply-To: <fead1ceb-c3a2-4e61-9b11-f30da188d93a@arnaud-lcm.com>
On Wed, 12 Nov 2025 16:11:41 +0000
"Lecomte, Arnaud" <contact@arnaud-lcm.com> wrote:
> On 12/11/2025 14:47, Brahmajit Das wrote:
> > On 12.11.2025 13:35, David Laight wrote:
> >> On Tue, 11 Nov 2025 13:42:54 +0530
> >> Brahmajit Das <listout@listout.xyz> wrote:
> >>
> > ...snip...
> >> Please can we have no unnecessary min_t().
> >> You wouldn't write:
> >> x = (u32)a < (u32)b ? (u32)a : (u32)b;
> >>
> >> David
> >>
> >>> copy_len = trace_nr * elem_size;
> >>>
> >>> ips = trace->ip + skip;
> > Hi David,
> >
> > Sorry, I didn't quite get that. Would prefer something like:
> > trace_nr = (trace_nr <= num_elem) ? trace_nr : num_elem;
>
> min_t is a min with casting which is unnecessary in this case as
> trace_nr and num_elem are already u32.
Correct
David
>
> > The pre-refactor code.
> >
>
prev parent reply other threads:[~2025-11-12 21:37 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-10 18:41 [syzbot] [bpf?] KASAN: stack-out-of-bounds Write in __bpf_get_stack syzbot
2025-11-10 21:16 ` [RFC bpf-next PATCH] bpf: Clamp trace length in __bpf_get_stack to fix OOB write Brahmajit Das
2025-11-11 0:37 ` [PATCH bpf-next v2] " Brahmajit Das
2025-11-11 1:04 ` bot+bpf-ci
2025-11-11 8:12 ` [PATCH bpf-next v3] " Brahmajit Das
2025-11-12 1:44 ` Yonghong Song
2025-11-12 8:40 ` Lecomte, Arnaud
2025-11-12 8:58 ` Brahmajit Das
2025-11-13 12:49 ` Brahmajit Das
2025-11-13 13:26 ` Lecomte, Arnaud
2025-11-13 13:49 ` Brahmajit Das
2025-11-12 13:35 ` David Laight
2025-11-12 14:47 ` Brahmajit Das
2025-11-12 16:11 ` Lecomte, Arnaud
2025-11-12 21:37 ` David Laight [this message]
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