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 DB3E22D8DDA; Tue, 11 Nov 2025 01:13:14 +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=1762823594; cv=none; b=SOMbqt94axfD5Ixkf9wiNciiKymMOPgtzFj9FNnQzoug4rlhp8kv7bySd61g4bJ1tqxp8i50kLK6dMQBXJaIOHAQfVeZpf9EDqePUK24/E95hq3RvSwjlcU6rmAjc6q/rWRcstkbn1SERqcu81lGNU12i5MLlk/IIW7EyKIr9os= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762823594; c=relaxed/simple; bh=0qheAxGUoJPUHvFu1lNK/0FYj5M+NDvhw2ZOw/sFcKM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ryNlPbiVU5Zyuw5CK2SIK90XfN+Rv0AVGNUVBOvGkuvUFC9xj1eiM4A/iziXp5pLJhqxdqtYdFkuaMoyZovEKN54fvPvmr7TI6mz85YNNyfSCQuby5Ut7dyqs7p0AHzwGmuSFNBaQQcgTB/j1W3B1DNULKvDVj01Mfl88Qy24tI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1B+4NiDv; 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="1B+4NiDv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 78A4EC4CEFB; Tue, 11 Nov 2025 01:13:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1762823594; bh=0qheAxGUoJPUHvFu1lNK/0FYj5M+NDvhw2ZOw/sFcKM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1B+4NiDvfO5/Jj2ZCJ1UEH1et3OSYMn1ZcUy05r1wRuQzIxgyUlU3fsCLLDsO/JbY CzB4uhtLkpxM7SjAUnmxwNNDiuXWa3rGM8v1P2u11uK462+CWIMLfjlY5AotcBwaYr cX4rDNhu3PlGBlBEfgnvp7QDvleLEVPMAWW+3c4o= 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 6.17 332/849] char: misc: Does not request module for miscdevice with dynamic minor Date: Tue, 11 Nov 2025 09:38:22 +0900 Message-ID: <20251111004544.444096120@linuxfoundation.org> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251111004536.460310036@linuxfoundation.org> References: <20251111004536.460310036@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 6.17-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 255a164eec86d..4c276b8066ff8 100644 --- a/drivers/char/misc.c +++ b/drivers/char/misc.c @@ -132,7 +132,8 @@ 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); @@ -144,10 +145,11 @@ 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