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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48072CCA483 for ; Tue, 7 Jun 2022 21:36:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1380478AbiFGVfV (ORCPT ); Tue, 7 Jun 2022 17:35:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376925AbiFGUks (ORCPT ); Tue, 7 Jun 2022 16:40:48 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B91D181448; Tue, 7 Jun 2022 11:38:28 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id CA0A9B8237D; Tue, 7 Jun 2022 18:38:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 21C19C385A5; Tue, 7 Jun 2022 18:38:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654627105; bh=tXA80zgeHvd3RQs/l+A4Go4Qc+Cp8g/84RUiCzl4Tm8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=M2ePbAFikCTbREk3K2VUn6FV85CuxtXCL3qr7Bg4gArePmMHBv3UVS+6qoQg0g1V9 s6Dnu7vSpvmic/uvCd3930Jh4PDjs27JgNd0C3tFW455pWkNZVDe1lqHTwLSw0sjGe VeUGuefckSDCYihOzPCiTgpLqyUijX0VVmqtGgso= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johannes Berg , Kalle Valo Subject: [PATCH 5.17 620/772] wifi: mac80211: fix use-after-free in chanctx code Date: Tue, 7 Jun 2022 19:03:32 +0200 Message-Id: <20220607165007.206061402@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607164948.980838585@linuxfoundation.org> References: <20220607164948.980838585@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: Johannes Berg commit 2965c4cdf7ad9ce0796fac5e57debb9519ea721e upstream. In ieee80211_vif_use_reserved_context(), when we have an old context and the new context's replace_state is set to IEEE80211_CHANCTX_REPLACE_NONE, we free the old context in ieee80211_vif_use_reserved_reassign(). Therefore, we cannot check the old_ctx anymore, so we should set it to NULL after this point. However, since the new_ctx replace state is clearly not IEEE80211_CHANCTX_REPLACES_OTHER, we're not going to do anything else in this function and can just return to avoid accessing the freed old_ctx. Cc: stable@vger.kernel.org Fixes: 5bcae31d9cb1 ("mac80211: implement multi-vif in-place reservations") Signed-off-by: Johannes Berg Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20220601091926.df419d91b165.I17a9b3894ff0b8323ce2afdb153b101124c821e5@changeid Signed-off-by: Greg Kroah-Hartman --- net/mac80211/chan.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) --- a/net/mac80211/chan.c +++ b/net/mac80211/chan.c @@ -1746,12 +1746,9 @@ int ieee80211_vif_use_reserved_context(s if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) { if (old_ctx) - err = ieee80211_vif_use_reserved_reassign(sdata); - else - err = ieee80211_vif_use_reserved_assign(sdata); + return ieee80211_vif_use_reserved_reassign(sdata); - if (err) - return err; + return ieee80211_vif_use_reserved_assign(sdata); } /*