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 E1BE1274B46; Sat, 12 Sep 2026 14:47:12 +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=1789224434; cv=none; b=aOP5KmqyBpl+pmJKiA/DmzTxFJmCL2bKa4LKtumNK952PhS9WYUqCs2o2atQY3vslCXgoy2vBsxh9lie4BkAN1z1MFOs7YBy6gYhJUwfWRzwz4Bj90jy3yeZK7K6i0+t6tqUT31W34W90M4nWfL2kKw2IcvK1veOBsvzPhJI3hw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789224434; c=relaxed/simple; bh=Nt0yhAbqrjTPbsVpi//iASVWzjeH8I6RgjQjwZfZZ+A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iHZwNSwQHYwnRyftytFi0oT4R6kMFF2SK2HubDImQ7WtTrQFLYf/8sR0Q5DkBr6C/VHO61hrWzbWg94jV+GybmVR6VibibGOc+/ZbJdoHFJvbEszVpWjjXNzUv49xf/AOfWeVm9NWZlH3Qd5JwoWfaE7Ygn+1164NpjxpVsj6ZU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=H2Z6fH+g; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="H2Z6fH+g" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E79E91F000FF; Sat, 12 Sep 2026 14:47:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789224432; bh=j6b5TgHo07ywm5qlCgRYKDD9kOX2/Le5d3d2mk1/n3w=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=H2Z6fH+guXZw8GCkxPXEAzIZzFJMS5ITzonjd4ApdPnJ4sKdSG/0AQfxWFVVECJ0q UULW3JyifbNLM/eIgoIyd2/nMMqtJ4kUHi6Vd/ui5HMauB1fRJGyDFwzFJ2NNF+5VU seUAWtBMbLAu9DbKM7nw4anJDImtWuGGWPPWoXWY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, sashiko-bot , "Zhang, Yanmin" , Arnaldo Carvalho de Melo , Namhyung Kim , Sasha Levin Subject: [PATCH 6.6 0990/1424] perf machine: Check snprintf truncation in machines__findnew() Date: Sat, 12 Sep 2026 08:57:02 +0200 Message-ID: <20260912065629.486451043@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.279695368@linuxfoundation.org> References: <20260912065607.279695368@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnaldo Carvalho de Melo [ Upstream commit cc6abe0012bf8c04af8275266f8ed7c55ba4a5fb ] The guestmount path is built with snprintf() into a PATH_MAX buffer without checking the return value. If symbol_conf.guestmount is long enough to cause truncation, the truncated path could match a different directory, causing the wrong guest to be associated with the pid. Check for truncation and bail out early. Fixes: a1645ce12adb ("perf: 'perf kvm' tool for monitoring guest performance from host") Reported-by: sashiko-bot Cc: Zhang, Yanmin Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Namhyung Kim Signed-off-by: Sasha Levin --- tools/perf/util/machine.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 6b9184e6efc81..3245c035d96d9 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -369,7 +369,12 @@ struct machine *machines__findnew(struct machines *machines, pid_t pid) if ((pid != HOST_KERNEL_ID) && (pid != DEFAULT_GUEST_KERNEL_ID) && (symbol_conf.guestmount)) { - snprintf(path, sizeof(path), "%s/%d", symbol_conf.guestmount, pid); + if (snprintf(path, sizeof(path), "%s/%d", + symbol_conf.guestmount, pid) >= (int)sizeof(path)) { + pr_err("Guest path too long for pid %d\n", pid); + machine = NULL; + goto out; + } if (access(path, R_OK)) { static struct strlist *seen; -- 2.53.0