From patchwork Sat Feb 13 13:36:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Markus Theil X-Patchwork-Id: 382820 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, 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 9139EC433E0 for ; Sat, 13 Feb 2021 13:38:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 57BF760232 for ; Sat, 13 Feb 2021 13:38:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230017AbhBMNhu (ORCPT ); Sat, 13 Feb 2021 08:37:50 -0500 Received: from smail.rz.tu-ilmenau.de ([141.24.186.67]:53433 "EHLO smail.rz.tu-ilmenau.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230015AbhBMNhr (ORCPT ); Sat, 13 Feb 2021 08:37:47 -0500 Received: from legolas.fritz.box (unknown [84.174.249.156]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smail.rz.tu-ilmenau.de (Postfix) with ESMTPSA id 8DAE458004F; Sat, 13 Feb 2021 14:37:03 +0100 (CET) From: Markus Theil To: johannes@sipsolutions.net Cc: linux-wireless@vger.kernel.org, Markus Theil , syzbot+93976391bf299d425f44@syzkaller.appspotmail.com Subject: [PATCH] mac80211: fix double free in ibss_leave Date: Sat, 13 Feb 2021 14:36:53 +0100 Message-Id: <20210213133653.367130-1-markus.theil@tu-ilmenau.de> X-Mailer: git-send-email 2.30.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Clear beacon ie pointer and ie length after free in order to prevent double free. ================================================================== BUG: KASAN: double-free or invalid-free \ in ieee80211_ibss_leave+0x83/0xe0 net/mac80211/ibss.c:1876 CPU: 0 PID: 8472 Comm: syz-executor100 Not tainted 5.11.0-rc6-syzkaller #0 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2c6 mm/kasan/report.c:230 kasan_report_invalid_free+0x51/0x80 mm/kasan/report.c:355 ____kasan_slab_free+0xcc/0xe0 mm/kasan/common.c:341 kasan_slab_free include/linux/kasan.h:192 [inline] __cache_free mm/slab.c:3424 [inline] kfree+0xed/0x270 mm/slab.c:3760 ieee80211_ibss_leave+0x83/0xe0 net/mac80211/ibss.c:1876 rdev_leave_ibss net/wireless/rdev-ops.h:545 [inline] __cfg80211_leave_ibss+0x19a/0x4c0 net/wireless/ibss.c:212 __cfg80211_leave+0x327/0x430 net/wireless/core.c:1172 cfg80211_leave net/wireless/core.c:1221 [inline] cfg80211_netdev_notifier_call+0x9e8/0x12c0 net/wireless/core.c:1335 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2040 call_netdevice_notifiers_extack net/core/dev.c:2052 [inline] call_netdevice_notifiers net/core/dev.c:2066 [inline] __dev_close_many+0xee/0x2e0 net/core/dev.c:1586 __dev_close net/core/dev.c:1624 [inline] __dev_change_flags+0x2cb/0x730 net/core/dev.c:8476 dev_change_flags+0x8a/0x160 net/core/dev.c:8549 dev_ifsioc+0x210/0xa70 net/core/dev_ioctl.c:265 dev_ioctl+0x1b1/0xc40 net/core/dev_ioctl.c:511 sock_do_ioctl+0x148/0x2d0 net/socket.c:1060 sock_ioctl+0x477/0x6a0 net/socket.c:1177 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported-by: syzbot+93976391bf299d425f44@syzkaller.appspotmail.com Signed-off-by: Markus Theil --- net/mac80211/ibss.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c index 1f552f374e97..a7ac53a2f00d 100644 --- a/net/mac80211/ibss.c +++ b/net/mac80211/ibss.c @@ -1874,6 +1874,8 @@ int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) /* remove beacon */ kfree(sdata->u.ibss.ie); + sdata->u.ibss.ie = NULL; + sdata->u.ibss.ie_len = 0; /* on the next join, re-program HT parameters */ memset(&ifibss->ht_capa, 0, sizeof(ifibss->ht_capa));