From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sipsolutions.net (s3.sipsolutions.net [168.119.38.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6628F3BE17F; Mon, 6 Jul 2026 11:50:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=168.119.38.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783338647; cv=none; b=EU6QPovESJbc3eQgz3aEDLlYgfMF6a5AOB/gAmc0iGyNCQmcucuQFWFgmtsMWwLYH5rq7cWte5CS78pXBx2RYqhvSO2NbygS8H1jE8DhaY1JssEMKI7KcV56jhDxbMJyAtn3lAHB5BHeE8m6/xcqir03GeMrZ4bFI2has5sRG1w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783338647; c=relaxed/simple; bh=HXUcfuHOZrrP1VZnW2aHgFlqkUZyaY85JueyXtjKaPw=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=XX3lIVl8mgP9OAmRSthW+J2nhvM3P0GfSvCnQUl+xhGAei70RwTVTsJk9HfS7te3MdGnQ2Ldi04RuFoYPY2xrehwwjKg3Y1Fnx2Uzm87ufJilW1BQuRegxgOnPES0BHH8WhNYYt7oX4shthoFo5A3ehHzJABAYQx2UgMbI63JSk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=permerror header.from=sipsolutions.net; spf=none smtp.mailfrom=sipsolutions.net; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b=V/alNT4L; arc=none smtp.client-ip=168.119.38.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=permerror header.from=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b="V/alNT4L" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=HXUcfuHOZrrP1VZnW2aHgFlqkUZyaY85JueyXtjKaPw=; t=1783338645; x=1784548245; b=V/alNT4LGUqQMgZcTpSV8K+CRIVJPrgxOvaP1BOjo2YAraA 6TOG/Hfxz7rEb7ZDY0kzEXRKlJ56QACU6SAbG8N2BOWx+K3iW1SkQGRQra7Op38nBwFMgY8dxpDbh ArHHfoQFF05FksFLPSM95G+sTAbG8V2amTtXhB1NRVimXFUZgF16RYFSHXGnZ0yvbqxHcaLssb2Gf gdo+O2LlhORowCW94PyEFcgnXTu9KL7Kb4Wc7iC+YDofeZPbjzX+uGR1QDmtHPXYrg/CnJr3xh/oU lxiGCzlE0UDa1b+vQ4HCgFD3vo8jK9SlMNyC2vit6vt2678sB8mqgyYsL3UNahew==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__ECDSA_SECP256R1_SHA256__AES_256_GCM:256) (Exim 4.98.2) (envelope-from ) id 1wghqU-0000000DNmg-2eGs; Mon, 06 Jul 2026 13:50:42 +0200 Message-ID: Subject: Re: [PATCH wireless] wifi: mac80211: clear beaconing state in ieee80211_do_stop() From: Johannes Berg To: Hojun Choi Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, Deepak Karn , syzbot+ca7a2759caaa6cd4e3db@syzkaller.appspotmail.com Date: Mon, 06 Jul 2026 13:50:41 +0200 In-Reply-To: <20260628141311.12488-1-ghwns6743@gmail.com> (sfid-20260628_161235_921778_27378788) References: <20260628130802.7698-1-ghwns6743@gmail.com> <20260628141311.12488-1-ghwns6743@gmail.com> (sfid-20260628_161235_921778_27378788) Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.58.3 (3.58.3-1.fc43) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-malware-bazaar: not-scanned On Sun, 2026-06-28 at 23:13 +0900, Hojun Choi wrote: > Following up with the concrete path, since the question is whether > cfg80211_leave() already covers this. It does not for AP start failure: > ieee80211_start_ap() sets enable_beacon before its fail-able steps, but > its error path (cfg.c:1930) only releases the channel, never clearing it > (unlike the IBSS/mesh paths), while cfg80211 leaves ap.beacon_interval at > 0. A later interface-down then makes ___cfg80211_stop_ap() short-circuit > (-ENOENT, net/wireless/ap.c:30) and skip the stop_ap clear, so > ieee80211_do_stop() runs with enable_beacon still set. I could not get a > driver to fail start_ap() there, so this is by inspection, not a > reproducer. How did syzbot hit it then? > I can fold this into the commit message in a v2, or instead fix the > producer by clearing enable_beacon on the start_ap() error path > (mirroring IBSS/mesh) - whichever you prefer. I used do_stop() since > you suggested it might need to clear that bit. Who is "you" here? I guess not me? It seems to me the cleanup paths make more sense though? This looks really quite out-of-place in do_stop() I think, especially the offchannel bit? How would that even happen? johannes