From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.manguebit.org (mx1.manguebit.org [143.255.12.172]) (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 B267437E304; Sun, 13 Sep 2026 18:26:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=143.255.12.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789323984; cv=none; b=WQGCQQ9EyKpC+RcTR3Aab2aIdolxBVFSDAHIbyP1/iU9QbNjJ9fGD3RdjY6LzGj13zTUcCEXqotdbGpeRJiftVeMCHBM7f1WvzO6WWnAaJ8t8znPR63U3yq6TyxCQkaBBSwp+o/pTUoDqUZQQJJVBM57VN27wBRsmW4TXMMUvoM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789323984; c=relaxed/simple; bh=aMz3LhyvzL0UNX+fKfz5MaMvXA88V+072oEqKjTlUrY=; h=Message-ID:From:To:Cc:Subject:In-Reply-To:References:Date: MIME-Version:Content-Type; b=GccaZIC1Rid9EC9Q0bJktIdr9tAMXnKHtg/vAtnOi/YHYzBks1K7sLjaHVYDPgl3ltTiO9o/6XNoytY41gOZ35XWdxXFYiZQ6jJEU3LvvD3Vii3+4if1Whm8v1SNiaCP105gLsd0bqlfairQnIRJXUfzLzz7RGu49ffhh+vSVAA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=manguebit.org; spf=pass smtp.mailfrom=manguebit.org; dkim=pass (2048-bit key) header.d=manguebit.org header.i=@manguebit.org header.b=Ej0G+AaO; arc=none smtp.client-ip=143.255.12.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=manguebit.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=manguebit.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=manguebit.org header.i=@manguebit.org header.b="Ej0G+AaO" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=manguebit.org; s=dkim; h=Content-Type:MIME-Version:Date:References: In-Reply-To:Subject:Cc:To:From:Message-ID:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=ppfZBqrKZfnd3U/kNsshWPsEGj74HFB25woC8i2RF7s=; b=Ej0G+AaOzSYcGkTEjAO4cwHLjo aisgARYX/5UgFaJuC/jPP2J4OF0DUzoLiSW+vECox5sJxeg0w76GSoQbjIAQNhIygUlBtYHn5fjBX nauPq3n1gX5MWnLFm+Vdt2dkScnuiFt1JqS5LKpOL7aN/kzhxc5ew/meTB+wTdwjsbFJOa9ccvZwg J7f/vS35+uHz8tLoMX5oOat1KqFz9cLhV91c3+awKEp69UX+2jG6ye+LeTxcLDSFBkl2bpgr5Ijkw PU7Q/+ly51q+fYIBVanN40sLgjJR1ZdGCqzJ6aBHUspXL7eRt86a/u0ewWx47XsLUO8hm8K8XU58r WFbEs7Wg==; Received: from pc by mx1.manguebit.org with local (Exim 4.99.5) id 1x5ou2-00000001LCP-1GWL; Sun, 13 Sep 2026 15:26:10 -0300 Message-ID: From: Paulo Alcantara To: linux-cifs@vger.kernel.org Cc: syzbot+5003556314abc915a71f@syzkaller.appspotmail.com, David Howells , Shyam Prasad N , Ronnie Sahlberg , Tom Talpey , Bharath SM , Namjae Jeon , stable@vger.kernel.org Subject: Re: [PATCH] smb: client: cancel reconnect work in clean_demultiplex_info() In-Reply-To: <20260912152008.392251-1-pc@manguebit.org> References: <20260912152008.392251-1-pc@manguebit.org> Date: Sun, 13 Sep 2026 15:26:09 -0300 Precedence: bulk X-Mailing-List: linux-cifs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Paulo Alcantara writes: > clean_demultiplex_info() cancels server->echo delayed work but not > server->reconnect, which can cause a use-after-free when the > demultiplex thread exits while a reconnect work is still queued: > > cifs_demultiplex_thread() > cifs_readv_from_socket() > cifs_reconnect() > __cifs_reconnect() > cifs_queue_server_reconn() > mod_delayed_work(cifsiod_wq, &server->reconnect, 0) > clean_demultiplex_info() > cancel_delayed_work_sync(&server->echo) // echo canceled > // reconnect NOT canceled > kfree_sensitive(server) // server freed > > ...later, on cifsiod_wq: > > smb2_reconnect_server() > server->srv_count // UAF read of freed server > > Fix this by canceling server->reconnect delayed work in > clean_demultiplex_info() before the server is freed, the same way > cifs_put_tcp_session() already does. > ... Applied.