From: Steven Rostedt <rostedt@goodmis.org>
To: Sam Moelius <sam.moelius@trailofbits.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH] tracing: Reject tracefs buffer size values that overflow bytes
Date: Tue, 2 Jun 2026 16:03:04 -0400 [thread overview]
Message-ID: <20260602160304.0b1f2b81@fedora> (raw)
In-Reply-To: <20260602184335.1554470-1-sam.moelius@trailofbits.com>
On Tue, 2 Jun 2026 18:43:34 +0000
Sam Moelius <sam.moelius@trailofbits.com> wrote:
> From: Samuel Moelius <sam.moelius@trailofbits.com>
>
> `tracing_entries_write()` accepts a `buffer_size_kb` value as
> `unsigned long`, checks only for zero, then shifts left by 10. On
> 64-bit, writing `18014398509481984` KB wraps the byte count to zero
> and the ring buffer resize path accepts it as a tiny buffer instead
> of rejecting an impossible huge size.
>
> The fix also adds the same pre-scale overflow check to
> `buffer_subbuf_size_write()`.
Honestly, enter stupid values, get stupid results.
I don't think this is necessary. Nothing breaks but the person may get
confused by being confused by the confusing entries they make.
-- Steve
prev parent reply other threads:[~2026-06-02 20:03 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-02 18:43 [PATCH] tracing: Reject tracefs buffer size values that overflow bytes Sam Moelius
2026-06-02 20:03 ` Steven Rostedt [this message]
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