From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 60FBA7465 for ; Sat, 30 Dec 2023 11:43:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="zRNrRS06" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91CA6C433C7; Sat, 30 Dec 2023 11:43:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1703936597; bh=f+SrcJ3wSfMf1gdNgdTBMGxkYCdL2vJAYm4maE+IBXY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=zRNrRS06lMN/ISyGFF0Ry1bGcPa3V4Xe0vvG+bohbrYbOphX16DOPQf5tvjiqixST MIzo/jYzSP+e10hAlt2ALaczXiX/OEQsTlwiGfAgRhgjdGRuTVbg4AbqNf7Fio9A6V r1djAoP6HQL5A0z4GjqKZWqiMCCk1PlfJZ50e4BE= Date: Sat, 30 Dec 2023 11:43:15 +0000 From: Greg KH To: =?iso-8859-1?B?TOlv?= Lam Cc: stable@vger.kernel.org, Philip =?iso-8859-1?Q?M=FCller?= , Johannes Berg Subject: Re: [PATCH 2/2] wifi: nl80211: fix deadlock in nl80211_set_cqm_rssi (6.6.x) Message-ID: <2023123005-annuity-numbly-e6d8@gregkh> References: <20231216054715.7729-2-leo@leolam.fr> <20231216054715.7729-4-leo@leolam.fr> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20231216054715.7729-4-leo@leolam.fr> On Sat, Dec 16, 2023 at 05:47:17AM +0000, Léo Lam wrote: > Commit 008afb9f3d57 ("wifi: cfg80211: fix CQM for non-range use" > backported to 6.6.x) causes nl80211_set_cqm_rssi not to release the > wdev lock in some of the error paths. > > Of course, the ensuing deadlock causes userland network managers to > break pretty badly, and on typical systems this also causes lockups on > on suspend, poweroff and reboot. See [1], [2], [3] for example reports. > > The upstream commit 7e7efdda6adb ("wifi: cfg80211: fix CQM for non-range > use"), committed in November 2023, is completely fine because there was > another commit in August 2023 that removed the wdev lock: > see commit 076fc8775daf ("wifi: cfg80211: remove wdev mutex"). > > The reason things broke in 6.6.5 is that commit 4338058f6009 was applied > without also applying 076fc8775daf. > > Commit 076fc8775daf ("wifi: cfg80211: remove wdev mutex") is a rather > large commit; adjusting the error handling (which is what this commit does) > yields a much simpler patch and was tested to work properly. > > Fix the deadlock by releasing the lock before returning. > > [1] https://bugzilla.kernel.org/show_bug.cgi?id=218247 > [2] https://bbs.archlinux.org/viewtopic.php?id=290976 > [3] https://lore.kernel.org/all/87sf4belmm.fsf@turtle.gmx.de/ > > Link: https://lore.kernel.org/stable/e374bb16-5b13-44cc-b11a-2f4eefb1ecf5@manjaro.org/ > Fixes: 008afb9f3d57 ("wifi: cfg80211: fix CQM for non-range use") > Tested-by: Léo Lam > Tested-by: Philip Müller > Cc: stable@vger.kernel.org > Cc: Johannes Berg > Signed-off-by: Léo Lam > --- > net/wireless/nl80211.c | 18 ++++++++++++------ > 1 file changed, 12 insertions(+), 6 deletions(-) Both now queued up, thanks. greg k-h