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 9D3FC1D04A8; Wed, 2 Oct 2024 14:28:37 +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=1727879317; cv=none; b=CjaODlWGMXcD3OECFYPkiHLfguMBSv8O1YWRAdXQComND4jHkBIeKh9WNSif4fa2daHmr3/MyWGsbR9PjIwR0iOzt0veVcdB1B+8df8Orti4bMh4lGIU6DRUTygUCqhflESzpXo2fJFE9QzRW17osk+Mq2PqBYyNFVuBj2Oq5CI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727879317; c=relaxed/simple; bh=g06iMQIDoGAdNQQPRiMEd24jS+8cXi1JTLrX+UWP+jE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dhPJrPCj3gPpNUil0Of4VJ5Jj2fGFWLb/n+NzCMCtEmYqg1f13JzEFI5bPmvT8QO3xOdw0wgZvnQa0IJfhDanHHgdS1CzhpnXZix7q+uT4NHqKZPoY4PpEZpMnfAlvsXttHRML+P3oBkraCsswqbsFevNnONCnXuc/bhxlPYVdc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CkcXJ+MU; 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="CkcXJ+MU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27A24C4CEC2; Wed, 2 Oct 2024 14:28:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1727879317; bh=g06iMQIDoGAdNQQPRiMEd24jS+8cXi1JTLrX+UWP+jE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CkcXJ+MUs9RoD7NhzWpqmQ5Vq6h3rnFuDx0JH28H7zAhzZ+T32eT/Sl3RoB8NOj/m n6oHfceIjpU2mg4RsRYqnyNNZC6e7Vh7sDsTceBV9g/YofrzyNeaDxZRO9DXfEnCiT 7Tad9OEnZ6FKu4QjQ9gzCB3YrdZySeAm4qx7jirI= 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 6.6 060/538] wifi: mac80211: use two-phase skb reclamation in ieee80211_do_stop() Date: Wed, 2 Oct 2024 14:54:59 +0200 Message-ID: <20241002125754.575606778@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241002125751.964700919@linuxfoundation.org> References: <20241002125751.964700919@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: 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 a7c39e895b1e5..fae701248f058 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -466,6 +466,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, bool going_do { 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; @@ -652,18 +653,32 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, bool going_do skb_queue_purge(&sdata->status_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