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 5004754BD4; Tue, 27 Feb 2024 13:56:54 +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=1709042215; cv=none; b=F9uZ1TJRSnb0jLA3jL4z7LbEsg6oDi8ImPJSDxi0kHHSGkZmkBn2JOzuRl+/iunkkrqk8RjTdMkfMVmQQpIB2KqmjsMPI6kvkrv0HNIfk++cpXPnfiUR6T7EvK61WB6vkn5WwME1JKBLVR5phWVBPTZ2Ai118Svlk5aIPiIUFxs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709042215; c=relaxed/simple; bh=Uz/Y9tQQKSSGvYcPypidDtnM6VCkWlac0ibECJHrROk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=R85lbrNpbeyLh+PnE6UTwqu6u8Pjm7D6C4nYiyTnagRzblD4Tgtr+CURIKub0QNrnP/7yIv+T22e33KQqWUNDdfzPYntmIUT2H4QUB5AViem6HBE8YQFO/pwss1CypnlR4VqbsLGIEwoZVSyT3k+bY7r8IdtAvRas6i+wxvsNec= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=UwLSJEgu; 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="UwLSJEgu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 538F8C433C7; Tue, 27 Feb 2024 13:56:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1709042214; bh=Uz/Y9tQQKSSGvYcPypidDtnM6VCkWlac0ibECJHrROk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UwLSJEguFuZsgQybh8l0lx+nNGtPpBfF0b3Z2MS2z5TKVTChHRUYDuPB+altKTHFC 3/ulwUPt0so5rpWLHCHggSsOce1MBNRl9rLvqjMas5wOZ6EaWsyC52ijCXH/ZyHqhu /4Fr7NNCY3A6an907MK65K+QvUsQjMWeO/tZdKTg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xu Yang , Heikki Krogerus Subject: [PATCH 6.6 190/299] usb: roles: fix NULL pointer issue when put modules reference Date: Tue, 27 Feb 2024 14:25:01 +0100 Message-ID: <20240227131631.941817891@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240227131625.847743063@linuxfoundation.org> References: <20240227131625.847743063@linuxfoundation.org> User-Agent: quilt/0.67 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: Xu Yang commit 1c9be13846c0b2abc2480602f8ef421360e1ad9e upstream. In current design, usb role class driver will get usb_role_switch parent's module reference after the user get usb_role_switch device and put the reference after the user put the usb_role_switch device. However, the parent device of usb_role_switch may be removed before the user put the usb_role_switch. If so, then, NULL pointer issue will be met when the user put the parent module's reference. This will save the module pointer in structure of usb_role_switch. Then, we don't need to find module by iterating long relations. Fixes: 5c54fcac9a9d ("usb: roles: Take care of driver module reference counting") cc: stable@vger.kernel.org Signed-off-by: Xu Yang Acked-by: Heikki Krogerus Link: https://lore.kernel.org/r/20240129093739.2371530-1-xu.yang_2@nxp.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/roles/class.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) --- a/drivers/usb/roles/class.c +++ b/drivers/usb/roles/class.c @@ -21,6 +21,7 @@ static const struct class role_class = { struct usb_role_switch { struct device dev; struct mutex lock; /* device lock*/ + struct module *module; /* the module this device depends on */ enum usb_role role; /* From descriptor */ @@ -135,7 +136,7 @@ struct usb_role_switch *usb_role_switch_ usb_role_switch_match); if (!IS_ERR_OR_NULL(sw)) - WARN_ON(!try_module_get(sw->dev.parent->driver->owner)); + WARN_ON(!try_module_get(sw->module)); return sw; } @@ -157,7 +158,7 @@ struct usb_role_switch *fwnode_usb_role_ sw = fwnode_connection_find_match(fwnode, "usb-role-switch", NULL, usb_role_switch_match); if (!IS_ERR_OR_NULL(sw)) - WARN_ON(!try_module_get(sw->dev.parent->driver->owner)); + WARN_ON(!try_module_get(sw->module)); return sw; } @@ -172,7 +173,7 @@ EXPORT_SYMBOL_GPL(fwnode_usb_role_switch void usb_role_switch_put(struct usb_role_switch *sw) { if (!IS_ERR_OR_NULL(sw)) { - module_put(sw->dev.parent->driver->owner); + module_put(sw->module); put_device(&sw->dev); } } @@ -189,15 +190,18 @@ struct usb_role_switch * usb_role_switch_find_by_fwnode(const struct fwnode_handle *fwnode) { struct device *dev; + struct usb_role_switch *sw = NULL; if (!fwnode) return NULL; dev = class_find_device_by_fwnode(&role_class, fwnode); - if (dev) - WARN_ON(!try_module_get(dev->parent->driver->owner)); + if (dev) { + sw = to_role_switch(dev); + WARN_ON(!try_module_get(sw->module)); + } - return dev ? to_role_switch(dev) : NULL; + return sw; } EXPORT_SYMBOL_GPL(usb_role_switch_find_by_fwnode); @@ -338,6 +342,7 @@ usb_role_switch_register(struct device * sw->set = desc->set; sw->get = desc->get; + sw->module = parent->driver->owner; sw->dev.parent = parent; sw->dev.fwnode = desc->fwnode; sw->dev.class = &role_class;