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 4AC0D15E5BB; Sat, 1 Nov 2025 00:54:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761958488; cv=none; b=Y1BquLeIsopTJq9/Pipj3zhQhQSeul5Tnpqt6F+cV1vV9OlGbefZ/bPPrXpQlXnBj3NtE49n1biZVGX8R3FnY+vYidp80SAl5doNfq+zxTN1Tx+pxRE403XNL7afbhFuOZN/pq98BAlNvk2DFp2Qr/Lkg/1F3G78dvmGXSvC8J0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761958488; c=relaxed/simple; bh=Eo5T+ScCv4hBpdgIgzhuXEDLTwYWGx5IuWl7TxgQP/4=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=O6uEJnsdfMMQ61dKkAzv+Abe6dZikXLqlqYfnnTwbHTXlL1m8mWRD75rxTnhr2RCQTCFLjrVmSOoO+H1TfUWg8MIoTkTOUcG7Sg0Lt6RCtN9vs14PF+bsg0REexPxVGaFPfMdLF06pqxZyqbMWEItC84YfkH/QRptvLCOlDLl6E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=M1k9rlyg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="M1k9rlyg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 72753C4CEE7; Sat, 1 Nov 2025 00:54:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761958487; bh=Eo5T+ScCv4hBpdgIgzhuXEDLTwYWGx5IuWl7TxgQP/4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=M1k9rlygTMElVgSJxGl1zjYAwkZHvPEzwI3KNPMTiZcN3Q/+uTKa4BYIh30y+7o0x 0sXOulMsPRLgWdIKbuFYeDtZLIZlCWZVcdqnTPdxEbaqJQOStr3m5jvpA38gX/dWO0 /cASAb4HPftOQi8II3FgM4bYaPlrnHYQkosfZkqc3ACRIOHALrAGbM+vSGx69pZXp2 VKcqFWil6+WQ6l344DeJ6cGAyqI8mZxZ0M3giChOyotTBJWHwytOo6cwZkrESdj/eF MQkyqSCP1iG2lYTb9wxvmOKXKh31mfaD36chnmxjJJgublyJpdZISewpXd0EI6ACJx M+FfTU6tAKjMQ== Date: Fri, 31 Oct 2025 17:54:46 -0700 From: Jakub Kicinski To: Gustavo Luiz Duarte Cc: Breno Leitao , Andrew Lunn , "David S. Miller" , Eric Dumazet , Paolo Abeni , Matthew Wood , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net] netconsole: Acquire su_mutex before navigating configs hierarchy Message-ID: <20251031175446.24e280fa@kernel.org> In-Reply-To: <20251029-netconsole-fix-warn-v1-1-0d0dd4622f48@gmail.com> References: <20251029-netconsole-fix-warn-v1-1-0d0dd4622f48@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 29 Oct 2025 13:50:24 -0700 Gustavo Luiz Duarte wrote: > There is a race between operations that iterate over the userdata > cg_children list and concurrent add/remove of userdata items through > configfs. The update_userdata() function iterates over the > nt->userdata_group.cg_children list, and count_extradata_entries() also > iterates over this same list to count nodes. Teaching syzbot how to create a netconsole would probably go a long way towards catching these sort of issues. Looks like right now syzbot has coverage only for the paths that don't need a target: https://syzkaller.appspot.com/upstream/coverage?period=month