From patchwork Thu Feb 2 05:25:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 13125325 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 9C421C05027 for ; Thu, 2 Feb 2023 05:29:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230377AbjBBF3J (ORCPT ); Thu, 2 Feb 2023 00:29:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231936AbjBBF2Z (ORCPT ); Thu, 2 Feb 2023 00:28:25 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8563020D32; Wed, 1 Feb 2023 21:28:09 -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 ams.source.kernel.org (Postfix) with ESMTPS id 8B092B824BD; Thu, 2 Feb 2023 05:28:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD25FC4339C; Thu, 2 Feb 2023 05:28:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1675315687; bh=nv2Qqlsj2+1OK7qBLFpDl9kvNBYUdDR2EUyByUiFUks=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PDOyv9HyEEEm1mMma7zFwWbZkwzMocq6zarb2i37VNulT7a3osKH4xFUVY03G0uE1 G9Bwmbvnz5RC4xs3/JXAKDPjHyL8XyQlHwUOfYaY2O7EeS2FYUCn0LqwDkgDfwLfnE s3sda8oybqsTfOSmSaMbXMtcGUfRgWiqyCXHn/z4P+pF49eE3+iYY3FTgmah4dJ+47 //ln2un/CRFL1KDmQJmrY5Tdsts1oSbjNOnJvq7gT10MuzQl2+ZQoBSddMjS6KhSBN EW8r43JO3kEgOgmrmkMwrVmOCjrFGBsIt984oYH9qZmUl3imiZo/eL2Aa3O1lCu2dV HZ4Q10lxbQi0w== 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 4.19 11/16] exit: Allow oops_limit to be disabled Date: Wed, 1 Feb 2023 21:25:59 -0800 Message-Id: <20230202052604.179184-12-ebiggers@kernel.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230202052604.179184-1-ebiggers@kernel.org> References: <20230202052604.179184-1-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 fd65f4e651d55..e1d375df4f286 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -559,8 +559,9 @@ 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 5cd8a34257650..b2f0aaf6bee78 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -986,7 +986,7 @@ 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);