From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792984506; b=0wC8+qqhbd8CA/9e3fOlxoq6XBUWd4UtXpIQNERka8E5bZfK+MQ9Or7gfdWNyT6Ip5bZ lD/Xq8VEBU+OuPaO+DRHequ6qaxQH8lyYs/J3+F/uzgE8k1+VYfIjxdHJG9oTVBYZ/cPl oLwDc8CSxVK4bxjKDO9gM7Vf//HjqfzHmsppQj3xCeOhTw5naRHSbfcs/QSkfq1B9khYf wsIHCgC9wbC0MAE0HlFPgO8AXdmjVO7k5Ye5ZGqknF0GscHBZ4qLFS+g0OPzwrJI41nLz cxLGUyxVbmCucELgVYFBIPxpd6Ef9O8fzC2EmmCyxlEYtHJc5e7BS25M1MZE62zwszA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792984506; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=DFKNiPZn/yMuwd98rkS5hZfOJKFxSsBCWKv6y1kml4w=; b=rT9YibPvpYDKVBfxXmjldfxgT9nIojqsrgochJvZTZl6KWChEtLFie//WzKc657t68DB mtjmolNS6A97PP8GZuSWF0wOLWSpgHiLRjzdCQODBURtgy1TpQN7mjM4CvbStIo625WIa xUDwIGGG7d6nGDwtGZmYfOIm3Nf8qZfqihBipfTpoVidy1Bju2NytsKKHStisNxDoaho4 lhst9OxEIf70HIbyUlsVcKLkRCJ0pPfa0V/KPSKuBRGQbdXAYh3Kxt5ostFDQDEgmfiXa fp7DbA8wy3oop9tZW0lFcepnlJFLdFL4qQ0TEyCjrRnmXeY2BybAc2Xh7pbBuX47B2g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=dFzEcfhR; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with UTF8SMTPS id 070F5606A31D; Mon, 26 Oct 2026 03:15:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=dFzEcfhR Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id 0F57F1F01825; Mon, 26 Oct 2026 03:15:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792984505; bh=DFKNiPZn/yMuwd98rkS5hZfOJKFxSsBCWKv6y1kml4w=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=dFzEcfhRtexQRmLmzlaSbg/AVrJTv7HPZMN5/KU6Vv/3CaOqn9eXICUS32jU46UwP 0iZbw6YaXs/lPo2m2YE5zXfind8LMDa31sW/HCrIEBxhS9flxqZTyEMSN3WaYuY0gw nDv+sIwIJV5JlqqEuOdu4IHZ4/nSQj/f9Gmy2Mm9nIsx5eYjWnD11DQ6/Jatmvl4Yq pFLPPF9XrFDkDk6dncayi4WArH7xhxRpWTjgIfd+bdYaxTCYFpbxNCHi5wEboMoWkQ LrnrcwrenFiIhdCXoqkj88NNl9daYVuYpixKTKrxa0Xl4nCgbhF6ChRmeq8OLlU850 TdHzk5IvGRxVA== Date: Mon, 26 Oct 2026 05:15:02 +0200 From: Jarkko Sakkinen To: David Howells Cc: keyrings@vger.kernel.org, Eric Biggers , syzbot+c15de43f1e7fffbb7b9b@syzkaller.appspotmail.com, Andrew Morton , Paul Moore , James Morris , "Serge E. Hallyn" , "open list:LIBRARY CODE" , "open list:SECURITY SUBSYSTEM" Subject: Re: [PATCH] KEYS: dispatch key_gc_work to system_wq. Message-ID: References: <20261026031219.2627968-1-jarkko@kernel.org> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261026031219.2627968-1-jarkko@kernel.org> On Mon, Oct 26, 2026 at 05:12:18AM +0200, Jarkko Sakkinen wrote: > schedule_work() dispatches key_gc_work on the per-CPU system_wq, which can > choke the queue: > > BUG: workqueue lockup - pool cpus=0 node=0 flags=0x2 nice=0 stuck for 30s! > > Queue the work on system_dfl_long_wq instead, which is an unbounded wq for > long-running tasks i.e., it has the WQ_BOUND flag set and thus cannot hog > the CPU core. > > Link: https://lore.kernel.org/keyrings/20261024042944.52493-1-hackerowskiy@gmail.com/ > Reported-by: syzbot+c15de43f1e7fffbb7b9b@syzkaller.appspotmail.com > Closes: https://lore.kernel.org/all/6ad35b60.7952420f.283480.0360.GAE@google.com/T/ > Signed-off-by: Jarkko Sakkinen Because old code has weird assumptions regardless what code it is, if it has been for a while using one threading model, so I'm mainly concerned are there "pinned to a CPU" assumptions in the keyring GC? Br, Jarkko