From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4EBF7C4338F for ; Mon, 26 Jul 2021 15:44:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 38F1160F51 for ; Mon, 26 Jul 2021 15:44:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235772AbhGZPE0 (ORCPT ); Mon, 26 Jul 2021 11:04:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:43338 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235828AbhGZPDk (ORCPT ); Mon, 26 Jul 2021 11:03:40 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2038B60F22; Mon, 26 Jul 2021 15:44:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1627314248; bh=I2P/HKSHOQzt+1zw+yMkiZZVIGw37oF+WlVyIzs8Gaw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GWWIueClH2BOnG6OjAglpObxl0CKutOPPyPCgyhMtjPRy9VmpVHRqtjRk5rj/C4Rz 0jim8fjGv/JIr9UM7SD3E1EpLhTeoJb2Fxf/CtVKIf1k4XGXf4SSwkfBRFaYDSuzok VFphR6Jw9YRCp7RN9AJC3AzIGYzK1B3D8P5o3NaM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nguyen Dinh Phi , syzbot+10f1194569953b72f1ae@syzkaller.appspotmail.com, "David S. Miller" , Sasha Levin Subject: [PATCH 4.9 38/60] netrom: Decrease sock refcount when sock timers expire Date: Mon, 26 Jul 2021 17:38:52 +0200 Message-Id: <20210726153826.065942326@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210726153824.868160836@linuxfoundation.org> References: <20210726153824.868160836@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nguyen Dinh Phi [ Upstream commit 517a16b1a88bdb6b530f48d5d153478b2552d9a8 ] Commit 63346650c1a9 ("netrom: switch to sock timer API") switched to use sock timer API. It replaces mod_timer() by sk_reset_timer(), and del_timer() by sk_stop_timer(). Function sk_reset_timer() will increase the refcount of sock if it is called on an inactive timer, hence, in case the timer expires, we need to decrease the refcount ourselves in the handler, otherwise, the sock refcount will be unbalanced and the sock will never be freed. Signed-off-by: Nguyen Dinh Phi Reported-by: syzbot+10f1194569953b72f1ae@syzkaller.appspotmail.com Fixes: 63346650c1a9 ("netrom: switch to sock timer API") Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/netrom/nr_timer.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/net/netrom/nr_timer.c b/net/netrom/nr_timer.c index f0ecaec1ff3d..d1a0b7056743 100644 --- a/net/netrom/nr_timer.c +++ b/net/netrom/nr_timer.c @@ -125,11 +125,9 @@ static void nr_heartbeat_expiry(unsigned long param) is accepted() it isn't 'dead' so doesn't get removed. */ if (sock_flag(sk, SOCK_DESTROY) || (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) { - sock_hold(sk); bh_unlock_sock(sk); nr_destroy_socket(sk); - sock_put(sk); - return; + goto out; } break; @@ -150,6 +148,8 @@ static void nr_heartbeat_expiry(unsigned long param) nr_start_heartbeat(sk); bh_unlock_sock(sk); +out: + sock_put(sk); } static void nr_t2timer_expiry(unsigned long param) @@ -163,6 +163,7 @@ static void nr_t2timer_expiry(unsigned long param) nr_enquiry_response(sk); } bh_unlock_sock(sk); + sock_put(sk); } static void nr_t4timer_expiry(unsigned long param) @@ -172,6 +173,7 @@ static void nr_t4timer_expiry(unsigned long param) bh_lock_sock(sk); nr_sk(sk)->condition &= ~NR_COND_PEER_RX_BUSY; bh_unlock_sock(sk); + sock_put(sk); } static void nr_idletimer_expiry(unsigned long param) @@ -200,6 +202,7 @@ static void nr_idletimer_expiry(unsigned long param) sock_set_flag(sk, SOCK_DEAD); } bh_unlock_sock(sk); + sock_put(sk); } static void nr_t1timer_expiry(unsigned long param) @@ -212,8 +215,7 @@ static void nr_t1timer_expiry(unsigned long param) case NR_STATE_1: if (nr->n2count == nr->n2) { nr_disconnect(sk, ETIMEDOUT); - bh_unlock_sock(sk); - return; + goto out; } else { nr->n2count++; nr_write_internal(sk, NR_CONNREQ); @@ -223,8 +225,7 @@ static void nr_t1timer_expiry(unsigned long param) case NR_STATE_2: if (nr->n2count == nr->n2) { nr_disconnect(sk, ETIMEDOUT); - bh_unlock_sock(sk); - return; + goto out; } else { nr->n2count++; nr_write_internal(sk, NR_DISCREQ); @@ -234,8 +235,7 @@ static void nr_t1timer_expiry(unsigned long param) case NR_STATE_3: if (nr->n2count == nr->n2) { nr_disconnect(sk, ETIMEDOUT); - bh_unlock_sock(sk); - return; + goto out; } else { nr->n2count++; nr_requeue_frames(sk); @@ -244,5 +244,7 @@ static void nr_t1timer_expiry(unsigned long param) } nr_start_t1timer(sk); +out: bh_unlock_sock(sk); + sock_put(sk); } -- 2.30.2