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 70E4F23EA94; Mon, 13 Apr 2026 16:07:19 +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=1776096439; cv=none; b=gaqZDqQUr8S+mFwCuBiPRrinC89+WjyK+ZV5l2nTvIL67yWE8NQRFXrp+qvPTDcBPAhg8X7BOM/Vn8t7F+CPIuvj3hvQ+pFYG2zPBXE+YscvfDHtCArtW+y17ugiV23sxBcaV0Sz/5jbknQoQclVDWZ7RpeYlWbmpSerXzBalwE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776096439; c=relaxed/simple; bh=gT460WHf/xht0M8dA7zhT75btJcfS9y3c9FFj3hgXdk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qeFs7nH2Z+TCW3GXukBIMvifsJZPOZvd3dIvIe+9fj6XZXokrs+R/e6eSI6hY9VNyuKGHDHlRMXDKzGeOqjyjns75BBE1gx9ekyELsln7cxsDTPU+epBKIbLiN+LGkzmGwDeDfokPBnJ9QvNk1iu4bJJXnp6VtwLod4FSeTlHzo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=qfHV2M7T; 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="qfHV2M7T" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 08476C2BCAF; Mon, 13 Apr 2026 16:07:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776096439; bh=gT460WHf/xht0M8dA7zhT75btJcfS9y3c9FFj3hgXdk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qfHV2M7TLSTzOUCcWTVbKKVQou78SymcOTRPYExvMrI3nxZUY9N3O808pmn0zvfuX a55t/De9TBlq18Z3rFIGo8i5PcWCb+wsCUekNE9oHwkRrgVZ2fcJzrdZDlQbqQx5LD faLSlz1lrGfiXghthERBaelMs+ePCkCEGIEhlwAg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Johannes Berg , Yuan Tan , Yifan Wu , Juefei Pu , Xin Liu , stable , Johannes Berg Subject: [PATCH 6.18 04/83] net: rfkill: prevent unlimited numbers of rfkill events from being created Date: Mon, 13 Apr 2026 17:59:32 +0200 Message-ID: <20260413155731.190010748@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260413155731.019638460@linuxfoundation.org> References: <20260413155731.019638460@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Greg Kroah-Hartman commit ea245d78dec594372e27d8c79616baf49e98a4a1 upstream. Userspace can create an unlimited number of rfkill events if the system is so configured, while not consuming them from the rfkill file descriptor, causing a potential out of memory situation. Prevent this from bounding the number of pending rfkill events at a "large" number (i.e. 1000) to prevent abuses like this. Cc: Johannes Berg Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Cc: stable Signed-off-by: Greg Kroah-Hartman Link: https://patch.msgid.link/2026033013-disfigure-scroll-e25e@gregkh Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/rfkill/core.c | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) --- a/net/rfkill/core.c +++ b/net/rfkill/core.c @@ -73,11 +73,14 @@ struct rfkill_int_event { struct rfkill_event_ext ev; }; +/* Max rfkill events that can be "in-flight" for one data source */ +#define MAX_RFKILL_EVENT 1000 struct rfkill_data { struct list_head list; struct list_head events; struct mutex mtx; wait_queue_head_t read_wait; + u32 event_count; bool input_handler; u8 max_size; }; @@ -255,10 +258,12 @@ static void rfkill_global_led_trigger_un } #endif /* CONFIG_RFKILL_LEDS */ -static void rfkill_fill_event(struct rfkill_event_ext *ev, - struct rfkill *rfkill, - enum rfkill_operation op) +static int rfkill_fill_event(struct rfkill_int_event *int_ev, + struct rfkill *rfkill, + struct rfkill_data *data, + enum rfkill_operation op) { + struct rfkill_event_ext *ev = &int_ev->ev; unsigned long flags; ev->idx = rfkill->idx; @@ -271,6 +276,15 @@ static void rfkill_fill_event(struct rfk RFKILL_BLOCK_SW_PREV)); ev->hard_block_reasons = rfkill->hard_block_reasons; spin_unlock_irqrestore(&rfkill->lock, flags); + + scoped_guard(mutex, &data->mtx) { + if (data->event_count++ > MAX_RFKILL_EVENT) { + data->event_count--; + return -ENOSPC; + } + list_add_tail(&int_ev->list, &data->events); + } + return 0; } static void rfkill_send_events(struct rfkill *rfkill, enum rfkill_operation op) @@ -282,10 +296,10 @@ static void rfkill_send_events(struct rf ev = kzalloc(sizeof(*ev), GFP_KERNEL); if (!ev) continue; - rfkill_fill_event(&ev->ev, rfkill, op); - mutex_lock(&data->mtx); - list_add_tail(&ev->list, &data->events); - mutex_unlock(&data->mtx); + if (rfkill_fill_event(ev, rfkill, data, op)) { + kfree(ev); + continue; + } wake_up_interruptible(&data->read_wait); } } @@ -1186,10 +1200,8 @@ static int rfkill_fop_open(struct inode if (!ev) goto free; rfkill_sync(rfkill); - rfkill_fill_event(&ev->ev, rfkill, RFKILL_OP_ADD); - mutex_lock(&data->mtx); - list_add_tail(&ev->list, &data->events); - mutex_unlock(&data->mtx); + if (rfkill_fill_event(ev, rfkill, data, RFKILL_OP_ADD)) + kfree(ev); } list_add(&data->list, &rfkill_fds); mutex_unlock(&rfkill_global_mutex); @@ -1259,6 +1271,7 @@ static ssize_t rfkill_fop_read(struct fi ret = -EFAULT; list_del(&ev->list); + data->event_count--; kfree(ev); out: mutex_unlock(&data->mtx);