From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 4D58A3D3338; Fri, 12 Jun 2026 22:24:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781303084; cv=none; b=tWHRKa8OKB1on7EBvLGSnkgPygoLQvXgTuIpAoleI0X7Z9niDJxxmq3ifJv1IT5zmMmSti8YCcqNHLvcj44k1AaKgPfmK3pSNRGzx7H7RtROGEhiYPSPoY9sJvVQymzVLGv0wYAPfut5J8IrhAnYrXWXK0ctcqwZiWooUSKz8r8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781303084; c=relaxed/simple; bh=MOt3c1ftICu+qWVeOeX/X1xW0XC3TEh9ubHr7ByRYfo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Bsx30PSu9L4/yCn2Eed9vJWXvbqe4GcvXra2rjcbwaUa4ViciDq7jSXVgzmthXCDNv4Z8fh4esLSSEUCnUkadIm+rDUvq+8H9zgVz8UHf/nBFi0hbfvU1elhSpPLk2YvXxkGgXdKjLTZnfoJ4w15zhMiMVWdyWVs0PneA0I8o/8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lZbAKoCz; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lZbAKoCz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 854771F000E9; Fri, 12 Jun 2026 22:24:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781303083; bh=XrzfqI1vaU2tlrcUxifTMBQ2C6q9m0ksStEmoc8wi6g=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lZbAKoCztvM0IYafWB0pyEmbxy7xLtAnopiRO0t869P1XoAx6aFl8akRIbgyzT/2J 2JFWYvM9wbN6Mni6jGcq+dM2dgEjb5rnxYv25A/bGdBGqvbpqFi9DDhX1whKGU9uCw pfgrhWwGryGbU1AscEEsZmKWOM1H204yAQVY+/b8Ky+jgk47kshm8IZGopO2ALQ0h4 IoehPFxSOSSdarJmvt2c8j8qhvrJoDAxHv+Tt9Uzfrem/ppPaIRDxSZMLBq+T/V7qp u31txgNsOb3OQL+5RJm06d4m0FITdZsQsPilrsJsCavbVrWXBpOu+Ilm7dI1pA178x tW/3z9o9oo88A== From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: Ingo Molnar , Thomas Gleixner , James Clark , Jiri Olsa , Ian Rogers , Adrian Hunter , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , sashiko-bot , Zhang Yanmin , "Claude Opus 4.6" Subject: [PATCH 06/13] perf tools: Use snprintf() for root_dir path construction Date: Fri, 12 Jun 2026 19:24:05 -0300 Message-ID: <20260612222413.40791-7-acme@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260612222413.40791-1-acme@kernel.org> References: <20260612222413.40791-1-acme@kernel.org> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Arnaldo Carvalho de Melo get_kernel_version() in machine.c and dso__load_guest_kernel_sym() in symbol.c use sprintf() to construct paths by prepending root_dir to "/proc/version" and "/proc/kallsyms" respectively. Both write into PATH_MAX stack buffers, but root_dir comes from --guestmount or KVM configuration and is not length-checked. A root_dir at or near PATH_MAX causes a stack buffer overflow. Switch to snprintf() with sizeof(path) to prevent overflow. Reported-by: sashiko-bot Fixes: a1645ce12adb6c9c ("perf: 'perf kvm' tool for monitoring guest performance from host") Cc: Zhang Yanmin Assisted-by: Claude Opus 4.6 Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/machine.c | 2 +- tools/perf/util/symbol.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index da1ad58758afd9d9..58fa57e3d1a15f37 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -1336,7 +1336,7 @@ static char *get_kernel_version(const char *root_dir) char *name, *tmp; const char *prefix = "Linux version "; - sprintf(version, "%s/proc/version", root_dir); + snprintf(version, sizeof(version), "%s/proc/version", root_dir); file = fopen(version, "r"); if (!file) return NULL; diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 0c46b24ee0986059..c2328c9cec1565fc 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -2275,7 +2275,7 @@ static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map) if (!kallsyms_filename) return -1; } else { - sprintf(path, "%s/proc/kallsyms", machine->root_dir); + snprintf(path, sizeof(path), "%s/proc/kallsyms", machine->root_dir); kallsyms_filename = path; } -- 2.54.0