From patchwork Thu Feb 2 05:44:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 13125351 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E642FC61DA4 for ; Thu, 2 Feb 2023 05:45:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231546AbjBBFpk (ORCPT ); Thu, 2 Feb 2023 00:45:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41236 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230508AbjBBFpf (ORCPT ); Thu, 2 Feb 2023 00:45:35 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 24F6A37B46; Wed, 1 Feb 2023 21:45:27 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id AB5BD61783; Thu, 2 Feb 2023 05:45:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04CC1C433D2; Thu, 2 Feb 2023 05:45:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1675316726; bh=gTyWdbMQBkC6bj2L7uRC+LIn00TYkfea/W2V8Ev9Cfw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SXBa8TdiOhzgbCB7WRvrT5ADcJIuaKB97mPE95Zc7EPVXvPq+wcLlbwa4s8opZRnP BRL8M7CLTUpwAKPtU3NuqTMjplzmn9RGqxVEb7RrGv7JsMT6DFngJgKVscCwITjxBi U2QbvmFVihP+Lh9okXkpQy4Zy675b+hLY85XKIuoBIsFHBrK/2rX0nAj+lbjTOWFHI TrGby2TffvqjR/RF6FDnMLvOmpPYXWn/Z/bgxoYeh5UnAhMOTXP+CAoqq3m0122cit 28Id6Z4mnSOzjct6pk3h2G2vKvR+nidq/zs6DuzuSzFJ+PLPW/NIOCXRW5CwQLlwGF /YCtWwuVD4TEQ== From: Eric Biggers To: stable@vger.kernel.org Cc: Harshit Mogalapalli , Kees Cook , SeongJae Park , Seth Jenkins , Jann Horn , "Eric W . Biederman" , linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, Jonathan Corbet , Andrew Morton , Baolin Wang , "Jason A. Donenfeld" , Eric Biggers , Huang Ying , Arnd Bergmann , linux-doc@vger.kernel.org Subject: [PATCH 4.14 11/16] exit: Allow oops_limit to be disabled Date: Wed, 1 Feb 2023 21:44:01 -0800 Message-Id: <20230202054406.221721-12-ebiggers@kernel.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230202054406.221721-1-ebiggers@kernel.org> References: <20230202054406.221721-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org From: Kees Cook commit de92f65719cd672f4b48397540b9f9eff67eca40 upstream. In preparation for keeping oops_limit logic in sync with warn_limit, have oops_limit == 0 disable checking the Oops counter. Cc: Jann Horn Cc: Jonathan Corbet Cc: Andrew Morton Cc: Baolin Wang Cc: "Jason A. Donenfeld" Cc: Eric Biggers Cc: Huang Ying Cc: "Eric W. Biederman" Cc: Arnd Bergmann Cc: linux-doc@vger.kernel.org Signed-off-by: Kees Cook Signed-off-by: Eric Biggers --- Documentation/sysctl/kernel.txt | 5 +++-- kernel/exit.c | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 7b04c616c5901..b6124a4475fb7 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -519,8 +519,9 @@ scanned for a given scan. oops_limit: Number of kernel oopses after which the kernel should panic when -``panic_on_oops`` is not set. Setting this to 0 or 1 has the same effect -as setting ``panic_on_oops=1``. +``panic_on_oops`` is not set. Setting this to 0 disables checking +the count. Setting this to 1 has the same effect as setting +``panic_on_oops=1``. The default value is 10000. ============================================================== diff --git a/kernel/exit.c b/kernel/exit.c index 138b110bf83a1..73103e008a627 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -984,7 +984,7 @@ void __noreturn make_task_dead(int signr) * To make sure this can't happen, place an upper bound on how often the * kernel may oops without panic(). */ - if (atomic_inc_return(&oops_count) >= READ_ONCE(oops_limit)) + if (atomic_inc_return(&oops_count) >= READ_ONCE(oops_limit) && oops_limit) panic("Oopsed too often (kernel.oops_limit is %d)", oops_limit); do_exit(signr);