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 651491C5799; Sat, 12 Sep 2026 18:56:36 +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=1789239397; cv=none; b=DBJT764ym2u/CgWSsZGqwcTGikEzxkAtrYn49rnhnpW8DcsT5T81ySQSEai7x+Hxuq0Oex/gK6JyVLSVGUEP8KQITT4THKvK7N8or5q7OhxOmRlWNHOAp+UIDTqcf9dCiqYFlL66UVYHEttIlPOWBUQ10zSBap3awoyOHny5y/4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789239397; c=relaxed/simple; bh=iig7lm+xDVGz+g4wcYLXWk1w5Rx5CVNw1ZKMhGA3SGY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=giHZ0+dfj4LV5u5GSEtvA3D+vexMKSTkDZK8qGgpaE33404qnynmgJiyWbBwBiEwFG08/8rKU3Yrm50mHh/nnAIW8byBxgD8STn0tAHQBOaO/Fomr5m12/nZ1sGqcfvc5/6DstqJ0//2l/UE8PzgF9/Z4QUExkw07JmMRywOz+U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=clwzPLcO; 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="clwzPLcO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1FD551F000FF; Sat, 12 Sep 2026 18:56:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789239396; bh=7dqv38ZB6LzqxhiMD1uYv+rZjnMGr4jL0xZaZZR8tcw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=clwzPLcO4/bGgUxfV/3hwr2ljxVYcb951KiAFKl6X1u6z+Zw7YsvmVYbxdoT1altj kBYLQ8Fjke0qJD5t87YLLR4Y3b8VkZFQXZ6mxaSfThDcrUdEx1hIQl38FjxR8nQ7OY v+BjtSioNKjYg4/YT6IJhtPPffFuunTAlUKQjtJo= 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 5.15 656/935] perf machine: Check snprintf truncation in machines__findnew() Date: Sat, 12 Sep 2026 09:01:26 +0200 Message-ID: <20260912065541.887658184@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065526.833703348@linuxfoundation.org> References: <20260912065526.833703348@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 5.15-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 6c10a902cafa5..3fa2975a64ae1 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -348,7 +348,12 @@ 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