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 5C4BD30BF68; Mon, 13 Apr 2026 17:03:54 +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=1776099834; cv=none; b=B9K+ia0NbDZGEXa62uo9gT971YLdK0Yp1J9uSU1hCclGdkKdVvC/OYYUMKsejPDnlUO4x5sYugnvlq5NYoZFdUjRxrIxEFF5DfO35/VQfGNtUKgvlGFff8wUY9KNY6NbCgACqq7as5aCawKGvYzYoKnATYaoJWVUcqtFU8F1dU0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776099834; c=relaxed/simple; bh=JhnGT4iqx0Dbl5QjykIjlpeIEueGHOZlCrSGPUBD3cw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=D7Qf+aAWrTtwMgW5NGpEgx5Pki+i63DKQRiAVeCfZthtWvtByU0wS97pW6YD0I3OrAiu94rvyaddkLxgSSaTvmLrKbzVACfi3EbQ2/sNALkj83O5T+i3vqVnOrk2Ayj20VVOkmgrBGL7JVFz5lsLxiy3Pb+Dp4kY4J8HnyixaGk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zc3BzPTy; 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="zc3BzPTy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E8599C2BCAF; Mon, 13 Apr 2026 17:03:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776099834; bh=JhnGT4iqx0Dbl5QjykIjlpeIEueGHOZlCrSGPUBD3cw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zc3BzPTyEK7o9hrD4337769hPyfORgFf4qVD1st+AAbrLjy7R/cZGksM36XkvHRaP PEn1nYtssg7vkCwGxYvQ2C4YPuMyR6Azye+iZ7ASITAwAFKuVZ9zHBpzUDDx78TnsW NJyqkaK+j6dX5oOfL1i4HwFFvEtHN13Sp5TSYzJY= 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 , Sasha Levin Subject: [PATCH 5.10 460/491] net: rfkill: prevent unlimited numbers of rfkill events from being created Date: Mon, 13 Apr 2026 18:01:45 +0200 Message-ID: <20260413155836.259441726@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260413155819.042779211@linuxfoundation.org> References: <20260413155819.042779211@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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Greg Kroah-Hartman [ Upstream commit ea245d78dec594372e27d8c79616baf49e98a4a1 ] 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 [ replaced `rfkill_event_ext` with `rfkill_event`, `scoped_guard` with explicit mutex calls, and removed outer `data->mtx` lock in `rfkill_fop_open` to avoid deadlock with new internal locking ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/rfkill/core.c | 40 +++++++++++++++++++++++++++------------- 1 file changed, 27 insertions(+), 13 deletions(-) --- a/net/rfkill/core.c +++ b/net/rfkill/core.c @@ -71,11 +71,14 @@ struct rfkill_int_event { struct rfkill_event 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; }; @@ -252,9 +255,12 @@ static void rfkill_global_led_trigger_un } #endif /* CONFIG_RFKILL_LEDS */ -static void rfkill_fill_event(struct rfkill_event *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 *ev = &int_ev->ev; unsigned long flags; ev->idx = rfkill->idx; @@ -266,6 +272,16 @@ static void rfkill_fill_event(struct rfk ev->soft = !!(rfkill->state & (RFKILL_BLOCK_SW | RFKILL_BLOCK_SW_PREV)); spin_unlock_irqrestore(&rfkill->lock, flags); + + mutex_lock(&data->mtx); + if (data->event_count++ > MAX_RFKILL_EVENT) { + data->event_count--; + mutex_unlock(&data->mtx); + return -ENOSPC; + } + list_add_tail(&int_ev->list, &data->events); + mutex_unlock(&data->mtx); + return 0; } static void rfkill_send_events(struct rfkill *rfkill, enum rfkill_operation op) @@ -277,10 +293,10 @@ 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); } } @@ -1118,21 +1134,19 @@ static int rfkill_fop_open(struct inode init_waitqueue_head(&data->read_wait); mutex_lock(&rfkill_global_mutex); - mutex_lock(&data->mtx); /* - * start getting events from elsewhere but hold mtx to get - * startup events added first + * start getting events from elsewhere but hold rfkill_global_mutex + * to get startup events added first */ list_for_each_entry(rfkill, &rfkill_list, node) { ev = kzalloc(sizeof(*ev), GFP_KERNEL); if (!ev) goto free; - rfkill_fill_event(&ev->ev, rfkill, RFKILL_OP_ADD); - list_add_tail(&ev->list, &data->events); + if (rfkill_fill_event(ev, rfkill, data, RFKILL_OP_ADD)) + kfree(ev); } list_add(&data->list, &rfkill_fds); - mutex_unlock(&data->mtx); mutex_unlock(&rfkill_global_mutex); file->private_data = data; @@ -1140,7 +1154,6 @@ static int rfkill_fop_open(struct inode return stream_open(inode, file); free: - mutex_unlock(&data->mtx); mutex_unlock(&rfkill_global_mutex); mutex_destroy(&data->mtx); list_for_each_entry_safe(ev, tmp, &data->events, list) @@ -1200,6 +1213,7 @@ static ssize_t rfkill_fop_read(struct fi ret = -EFAULT; list_del(&ev->list); + data->event_count--; kfree(ev); out: mutex_unlock(&data->mtx);