From patchwork Fri Jun 18 10:41:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Coelho X-Patchwork-Id: 464202 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 3CF69C48BE8 for ; Fri, 18 Jun 2021 10:42:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 218B8613EC for ; Fri, 18 Jun 2021 10:42:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233792AbhFRKoS (ORCPT ); Fri, 18 Jun 2021 06:44:18 -0400 Received: from paleale.coelho.fi ([176.9.41.70]:48150 "EHLO farmhouse.coelho.fi" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S233678AbhFRKoR (ORCPT ); Fri, 18 Jun 2021 06:44:17 -0400 Received: from 91-156-6-193.elisa-laajakaista.fi ([91.156.6.193] helo=kveik.lan) by farmhouse.coelho.fi with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1luBwr-001YXx-KO; Fri, 18 Jun 2021 13:42:07 +0300 From: Luca Coelho To: johannes@sipsolutions.net Cc: luca@coelho.fi, linux-wireless@vger.kernel.org Date: Fri, 18 Jun 2021 13:41:31 +0300 Message-Id: X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210618104156.747775-1-luca@coelho.fi> References: <20210618104156.747775-1-luca@coelho.fi> MIME-Version: 1.0 Subject: [PATCH 06/31] cfg80211: avoid double free of PMSR request Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Avraham Stern If cfg80211_pmsr_process_abort() moves all the PMSR requests that need to be freed into a local list before aborting and freeing them. As a result, it is possible that cfg80211_pmsr_complete() will run in parallel and free the same PMSR request. Fix it by freeing the request in cfg80211_pmsr_complete() only if it is still in the original pmsr list. Signed-off-by: Avraham Stern Signed-off-by: Luca Coelho --- net/wireless/pmsr.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/net/wireless/pmsr.c b/net/wireless/pmsr.c index 6bdd96408022..d245968b74cb 100644 --- a/net/wireless/pmsr.c +++ b/net/wireless/pmsr.c @@ -334,6 +334,7 @@ void cfg80211_pmsr_complete(struct wireless_dev *wdev, gfp_t gfp) { struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy); + struct cfg80211_pmsr_request *tmp, *prev, *to_free = NULL; struct sk_buff *msg; void *hdr; @@ -364,9 +365,20 @@ void cfg80211_pmsr_complete(struct wireless_dev *wdev, nlmsg_free(msg); free_request: spin_lock_bh(&wdev->pmsr_lock); - list_del(&req->list); + /* + * cfg80211_pmsr_process_abort() may have already moved this request + * to the free list, and will free it later. In this case, don't free + * it here. + */ + list_for_each_entry_safe(tmp, prev, &wdev->pmsr_list, list) { + if (tmp == req) { + list_del(&req->list); + to_free = req; + break; + } + } spin_unlock_bh(&wdev->pmsr_lock); - kfree(req); + kfree(to_free); } EXPORT_SYMBOL_GPL(cfg80211_pmsr_complete);