From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4577937F721; Mon, 23 Mar 2026 12:06:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774267608; cv=none; b=VuUgE5+gOk5aQlqdESCQhZYbLJEITqe2g0hZo1fb7jwJNuagcs+AQTGcvxqqHyHm541xsyeHoDs4i6X0Yhi5BxiUPUDwit5vSs3MiLE9jfjG68oVbi9t1awy2Ke11na6gMkD+SEjeEtv9YTh8xJpGERpjYxjfUWeeiElWykjTI8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774267608; c=relaxed/simple; bh=G9WmYiLeswQv6Ve1LoG1uvOvj989vX1oUK2ETCU2J9o=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=tpGJj2kZTGGR78D2zKaVH8tvsBiYOMIXskg7G32MeOKIJxnD2S+S3JO4W2Lud1Hsd+rDC8Hdz5AKl7GoDfhHRJj2SzdIu8nb42mGJpsmeINsntBBRQdPtP7jZncJXKz1jFwP7Iu3iEp+09Dld493UIoO+W3tC8G1G1wR+Ee1W7A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FAGvZ4oK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FAGvZ4oK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23A87C2BCB6; Mon, 23 Mar 2026 12:06:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774267607; bh=G9WmYiLeswQv6Ve1LoG1uvOvj989vX1oUK2ETCU2J9o=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=FAGvZ4oKAXzn89bVfmJwx36J+WLBB9JqLS26s5DZ3196PgmbMyv0qN8iyM0GgRXVD AvuBq40yjlJH5KHLVncQtPIl87b4fG8A5Jzx9/gPZlwvd9EbFCkvE8xExW70b7h136 QOZKqXpmfeZ+u98/8ougbVxTh++6xKcTz9mfASbth5NBeCDntYRYVPTqXv2qeRtQ1D f6oa8yDVW8Sc0l0lFmETFJqCxGesqYKi+72T58hHA7jGJJ8dfzAE608KtKTMKA6y8K xy7eKpTBD9TpjVA0CzieNU6dF1ivluUXeAZPHyh9HodET+i+14/gRkt4eVyFLHWU4j Gbp1My3/gkliw== Date: Mon, 23 Mar 2026 21:06:43 +0900 From: Masami Hiramatsu (Google) To: Martin Kaiser Cc: Steven Rostedt , Mathieu Desnoyers , linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] tracing: fprobe: fix the length of unused fgraph_data Message-Id: <20260323210643.2b43b307f0348623d680b098@kernel.org> In-Reply-To: <20260323102020.239567-1-martin@kaiser.cx> References: <20260323102020.239567-1-martin@kaiser.cx> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 23 Mar 2026 11:19:36 +0100 Martin Kaiser wrote: > If fprobe_entry does not fill the allocated fgraph_data completely, the > unused part is zeroed with memset. > > Fix the length for this memset call. Both reserved_words and used are in > units of return stack words, but memset needs the number of bytes. > > Cc: stable@vger.kernel.org > Fixes: 4346ba160409 ("fprobe: Rewrite fprobe on function-graph tracer") > Signed-off-by: Martin Kaiser Good catch! Thanks, > --- > kernel/trace/fprobe.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c > index dcadf1d23b8a..6a1192515afd 100644 > --- a/kernel/trace/fprobe.c > +++ b/kernel/trace/fprobe.c > @@ -451,7 +451,7 @@ static int fprobe_fgraph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops > } > } > if (used < reserved_words) > - memset(fgraph_data + used, 0, reserved_words - used); > + memset(fgraph_data + used, 0, (reserved_words - used) * sizeof(long)); > > /* If any exit_handler is set, data must be used. */ > return used != 0; > -- > 2.43.7 > -- Masami Hiramatsu (Google)