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 E7B151DF24E; Wed, 6 Nov 2024 12:08:11 +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=1730894892; cv=none; b=DpF5e7xHk5b4XhmABrz0I1MdrcHpbW3kArvoIInesMqiSeg2XQAE59XhSoA/YHkaGXKAFYC2f/DPRk269zCSVCPpt6pVks8/qTPvI9hXOwFos6/HkbUz3QOADKPQ0wsE+rIPLRI0taP1kq9+WnkaDe7o2Wl4V8iyAxCrIoI2t60= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730894892; c=relaxed/simple; bh=1j0FbNtYGZic4dXTBRjkpMoON2cm8L1VZXjvaDjs9k8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pumOzF2mqfk5L2qKQxfUNubP18+vzumLv7xEkRPKZNSGosX4JnYY5VXoqK8upG0xL4VZwU4g9nAt1/oa6uM7ManWt5Vwtmwk/pXoZbVCrUmREE5tp6DMJuWWc+Z2p0TSZ57a04Q9+Lh7MsC6rB+FubjIxsy6gcqwTeN5F7TpIN8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=EGHfJ/Ge; 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="EGHfJ/Ge" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63B08C4CECD; Wed, 6 Nov 2024 12:08:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730894891; bh=1j0FbNtYGZic4dXTBRjkpMoON2cm8L1VZXjvaDjs9k8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EGHfJ/Ge0cyTlkEBDhP18Q2t9YbvTdPoFVrdomygZ3WPUTxXXpvka3to7IIDZ12Ys QaAj/lIZEnf2F1G0Sd6wod9poYzAedofZEZtq7xyeoLe7HQxfT0X0uLRy9I0QrLxW9 2NAw4M96z3Zjz1oEVyvJzNXIDlkoaqFWtABb3J9I= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+1a3986bbd3169c307819@syzkaller.appspotmail.com, Dmitry Antipov , Johannes Berg , Sasha Levin Subject: [PATCH 4.19 034/350] wifi: mac80211: use two-phase skb reclamation in ieee80211_do_stop() Date: Wed, 6 Nov 2024 12:59:22 +0100 Message-ID: <20241106120321.724391616@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241106120320.865793091@linuxfoundation.org> References: <20241106120320.865793091@linuxfoundation.org> User-Agent: quilt/0.67 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 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dmitry Antipov [ Upstream commit 9d301de12da6e1bb069a9835c38359b8e8135121 ] Since '__dev_queue_xmit()' should be called with interrupts enabled, the following backtrace: ieee80211_do_stop() ... spin_lock_irqsave(&local->queue_stop_reason_lock, flags) ... ieee80211_free_txskb() ieee80211_report_used_skb() ieee80211_report_ack_skb() cfg80211_mgmt_tx_status_ext() nl80211_frame_tx_status() genlmsg_multicast_netns() genlmsg_multicast_netns_filtered() nlmsg_multicast_filtered() netlink_broadcast_filtered() do_one_broadcast() netlink_broadcast_deliver() __netlink_sendskb() netlink_deliver_tap() __netlink_deliver_tap_skb() dev_queue_xmit() __dev_queue_xmit() ; with IRQS disabled ... spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags) issues the warning (as reported by syzbot reproducer): WARNING: CPU: 2 PID: 5128 at kernel/softirq.c:362 __local_bh_enable_ip+0xc3/0x120 Fix this by implementing a two-phase skb reclamation in 'ieee80211_do_stop()', where actual work is performed outside of a section with interrupts disabled. Fixes: 5061b0c2b906 ("mac80211: cooperate more with network namespaces") Reported-by: syzbot+1a3986bbd3169c307819@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=1a3986bbd3169c307819 Signed-off-by: Dmitry Antipov Link: https://patch.msgid.link/20240906123151.351647-1-dmantipov@yandex.ru Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- net/mac80211/iface.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 358028a09ce4d..433083cc15331 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -798,6 +798,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, { struct ieee80211_local *local = sdata->local; unsigned long flags; + struct sk_buff_head freeq; struct sk_buff *skb, *tmp; u32 hw_reconf_flags = 0; int i, flushed; @@ -996,18 +997,32 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, skb_queue_purge(&sdata->skb_queue); } + /* + * Since ieee80211_free_txskb() may issue __dev_queue_xmit() + * which should be called with interrupts enabled, reclamation + * is done in two phases: + */ + __skb_queue_head_init(&freeq); + + /* unlink from local queues... */ spin_lock_irqsave(&local->queue_stop_reason_lock, flags); for (i = 0; i < IEEE80211_MAX_QUEUES; i++) { skb_queue_walk_safe(&local->pending[i], skb, tmp) { struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); if (info->control.vif == &sdata->vif) { __skb_unlink(skb, &local->pending[i]); - ieee80211_free_txskb(&local->hw, skb); + __skb_queue_tail(&freeq, skb); } } } spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); + /* ... and perform actual reclamation with interrupts enabled. */ + skb_queue_walk_safe(&freeq, skb, tmp) { + __skb_unlink(skb, &freeq); + ieee80211_free_txskb(&local->hw, skb); + } + if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) ieee80211_txq_remove_vlan(local, sdata); -- 2.43.0