From patchwork Thu Nov 12 10:22:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Berg X-Patchwork-Id: 11899549 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D3074138B for ; Thu, 12 Nov 2020 10:22:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB1DC22203 for ; Thu, 12 Nov 2020 10:22:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727054AbgKLKWV (ORCPT ); Thu, 12 Nov 2020 05:22:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725902AbgKLKWU (ORCPT ); Thu, 12 Nov 2020 05:22:20 -0500 Received: from sipsolutions.net (s3.sipsolutions.net [IPv6:2a01:4f8:191:4433::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 17BACC0613D1; Thu, 12 Nov 2020 02:22:20 -0800 (PST) Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94) (envelope-from ) id 1kd9k8-006G8G-HC; Thu, 12 Nov 2020 11:22:16 +0100 From: Johannes Berg To: linux-wireless@vger.kernel.org Cc: Johannes Berg , stable@vger.kernel.org, syzbot+32c6c38c4812d22f2f0b@syzkaller.appspotmail.com, syzbot+4c81fe92e372d26c4246@syzkaller.appspotmail.com, syzbot+6a7fe9faf0d1d61bc24a@syzkaller.appspotmail.com, syzbot+abed06851c5ffe010921@syzkaller.appspotmail.com, syzbot+b7aeb9318541a1c709f1@syzkaller.appspotmail.com, syzbot+d5a9416c6cafe53b5dd0@syzkaller.appspotmail.com Subject: [PATCH] mac80211: free sta in sta_info_insert_finish() on errors Date: Thu, 12 Nov 2020 11:22:04 +0100 Message-Id: <20201112112201.ee6b397b9453.I9c31d667a0ea2151441cc64ed6613d36c18a48e0@changeid> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Johannes Berg If sta_info_insert_finish() fails, we currently keep the station around and free it only in the caller, but there's only one such caller and it always frees it immediately. As syzbot found, another consequence of this split is that we can put things that sleep only into __cleanup_single_sta() and not in sta_info_free(), but this is the only place that requires such of sta_info_free() now. Change this to free the station in sta_info_insert_finish(), in which case we can still sleep. This will also let us unify the cleanup code later. Cc: stable@vger.kernel.org Fixes: dcd479e10a05 ("mac80211: always wind down STA state") Reported-by: syzbot+32c6c38c4812d22f2f0b@syzkaller.appspotmail.com Reported-by: syzbot+4c81fe92e372d26c4246@syzkaller.appspotmail.com Reported-by: syzbot+6a7fe9faf0d1d61bc24a@syzkaller.appspotmail.com Reported-by: syzbot+abed06851c5ffe010921@syzkaller.appspotmail.com Reported-by: syzbot+b7aeb9318541a1c709f1@syzkaller.appspotmail.com Reported-by: syzbot+d5a9416c6cafe53b5dd0@syzkaller.appspotmail.com Signed-off-by: Johannes Berg --- net/mac80211/sta_info.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c index 4fe284ff1ea3..ec6973ee88ef 100644 --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -705,7 +705,7 @@ static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU) out_drop_sta: local->num_sta--; synchronize_net(); - __cleanup_single_sta(sta); + cleanup_single_sta(sta); out_err: mutex_unlock(&local->sta_mtx); kfree(sinfo); @@ -724,19 +724,13 @@ int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU) err = sta_info_insert_check(sta); if (err) { + sta_info_free(local, sta); mutex_unlock(&local->sta_mtx); rcu_read_lock(); - goto out_free; + return err; } - err = sta_info_insert_finish(sta); - if (err) - goto out_free; - - return 0; - out_free: - sta_info_free(local, sta); - return err; + return sta_info_insert_finish(sta); } int sta_info_insert(struct sta_info *sta)