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 30F4E3502B3; Fri, 21 Nov 2025 13:42:13 +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=1763732533; cv=none; b=Ha9S6tmJW++ijkH4eDAfSSd9iEx2NPEJ0+jy9uv0VyxxcjY/nKt5ILM2Co3dHbiwx9VGXeWDAmFbq+CWtF7YQlLyCwi0ASlBBA8CdhGYKbKvPGVgC/6D8/LoRjNspI1bwUuupjk/Cg0Cyr+CjQhJic5vikNvYTmWqeH3U/Ul2Yg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763732533; c=relaxed/simple; bh=ICsYJkkb3OKM+oSIsYn8QEruA6vEvdSAO1yPGiTrdyM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bDd6Q8LChf1+Ldso6ps3EUjnnyMqoJyJjgyYS7gZmu1ktX3XoBPtnS46Yffe1aKvIYztmteG0w2tRnvdrUJ8gKG706UOcuYv3jY8Xap/w+6FQpOAQVilDfPt6+kWUhrW6eEDniT6WpHOPHXFS84hecVbVRlOGgBi0aO1VfkkRUk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JmZ5P6Vf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JmZ5P6Vf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3394C4CEF1; Fri, 21 Nov 2025 13:42:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1763732533; bh=ICsYJkkb3OKM+oSIsYn8QEruA6vEvdSAO1yPGiTrdyM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JmZ5P6VfwlzfLpYxy85RYvxVpVUKTBG4JbDw9BbJzydkPXJ2bgGAox2Hck0nmQJK5 ygvi2FyhuQRDKabnzUEvrfVBRyIReT45WCeAUAppogKSKRKz8cdmRIMpJeXTdWWs5W k5/+38gLYHkQxoVhJ5ThOV5TCOUpSaPBoY0eYKNY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Thadeu Lima de Souza Cascardo , Zijun Hu , Sasha Levin Subject: [PATCH 6.6 154/529] char: misc: Does not request module for miscdevice with dynamic minor Date: Fri, 21 Nov 2025 14:07:33 +0100 Message-ID: <20251121130236.498506624@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251121130230.985163914@linuxfoundation.org> References: <20251121130230.985163914@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org 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: Zijun Hu [ Upstream commit 1ba0fb42aa6a5f072b1b8c0b0520b32ad4ef4b45 ] misc_open() may request module for miscdevice with dynamic minor, which is meaningless since: - The dynamic minor allocated is unknown in advance without registering miscdevice firstly. - Macro MODULE_ALIAS_MISCDEV() is not applicable for dynamic minor. Fix by only requesting module for miscdevice with fixed minor. Acked-by: Thadeu Lima de Souza Cascardo Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20250714-rfc_miscdev-v6-6-2ed949665bde@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/char/misc.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/char/misc.c b/drivers/char/misc.c index 9ee78c76e8663..6f9ce6b3cc5a6 100644 --- a/drivers/char/misc.c +++ b/drivers/char/misc.c @@ -150,7 +150,8 @@ static int misc_open(struct inode *inode, struct file *file) break; } - if (!new_fops) { + /* Only request module for fixed minor code */ + if (!new_fops && minor < MISC_DYNAMIC_MINOR) { mutex_unlock(&misc_mtx); request_module("char-major-%d-%d", MISC_MAJOR, minor); mutex_lock(&misc_mtx); @@ -162,10 +163,11 @@ static int misc_open(struct inode *inode, struct file *file) new_fops = fops_get(iter->fops); break; } - if (!new_fops) - goto fail; } + if (!new_fops) + goto fail; + /* * Place the miscdevice in the file's * private_data so it can be used by the -- 2.51.0