linux-kernel - Re: [PATCH v2] tracing: Consider the NULL character when validating the event length

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20241007114333.73f008d1@gandalf.local.home>
Date: Mon, 7 Oct 2024 11:43:33 -0400
From: Steven Rostedt <rostedt@...dmis.org>
To: Leo Yan <leo.yan@....com>
Cc: Masami Hiramatsu <mhiramat@...nel.org>, Mathieu Desnoyers
 <mathieu.desnoyers@...icios.com>, Dave.Martin@....com,
 linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org
Subject: Re: [PATCH v2] tracing: Consider the NULL character when validating
 the event length

On Mon,  7 Oct 2024 15:47:24 +0100
Leo Yan <leo.yan@....com> wrote:

> strlen() returns a string length excluding the null byte. If the string
> length equals to the maximum buffer length, the buffer will have no
> space for the NULL terminating character.
> 
> This commit checks this condition and returns failure for it.
> 
> Fixes: dec65d79fd26 ("tracing/probe: Check event name length correctly")
> Signed-off-by: Leo Yan <leo.yan@....com>

Reviewed-by: Steven Rostedt (Google) <rostedt@...dmis.org>

Masami, want to take this?

-- Steve

> ---
> 
> Changes from v1:
> Refined for condition checking (Steve).
> 
>  kernel/trace/trace_probe.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> index 39877c80d6cb..16a5e368e7b7 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -276,7 +276,7 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
>  		}
>  		trace_probe_log_err(offset, NO_EVENT_NAME);
>  		return -EINVAL;
> -	} else if (len > MAX_EVENT_NAME_LEN) {
> +	} else if (len >= MAX_EVENT_NAME_LEN) {
>  		trace_probe_log_err(offset, EVENT_TOO_LONG);
>  		return -EINVAL;
>  	}