From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out01.mta.xmission.com (out01.mta.xmission.com [166.70.13.231]) (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 553761D5AC5; Thu, 26 Sep 2024 19:10:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=166.70.13.231 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727377808; cv=none; b=FU0RgyNAMO0JPWFCpIUd//qgJIrBhmqA8cI+ksqlG+rsumluuv0OQgxCnQcjrpc+Tr5EbWW1lFolch9Ndiu/M+HgC7F35MLIkMseizpBEEGx0L0BAEC5PCeTX05aL/MDS4U9nvZRovJ7piq4tZXMibA+xOgfsm8FNHKNufiXkrs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727377808; c=relaxed/simple; bh=ZtuoSr9+AcXFNWqNVKenoqBbJvNgqAXYmZYFVmzCG0E=; h=From:To:Cc:References:Date:In-Reply-To:Message-ID:MIME-Version: Content-Type:Subject; b=YMr228E1F6WP+mVD77akJX6d2bD9K7KTUTAO0mFy2xtIN19NoEq57ZglVMdx3/V+3SMb61zm2F7eJHRr1PPPjBtg2JRIjiiY8xL/hsuZvh1AW8FKHMwD9HVdqxWR4rR8jH0CiQDVOLU3LfV6w/SSGZuCVwx9/f54Tnq4X3e4rDk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=xmission.com; spf=pass smtp.mailfrom=xmission.com; arc=none smtp.client-ip=166.70.13.231 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=xmission.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xmission.com Received: from in02.mta.xmission.com ([166.70.13.52]:58936) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1sttsL-0037Ht-DA; Thu, 26 Sep 2024 13:10:05 -0600 Received: from ip68-227-165-127.om.om.cox.net ([68.227.165.127]:44600 helo=email.froward.int.ebiederm.org.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1sttsK-00AixJ-HD; Thu, 26 Sep 2024 13:10:05 -0600 From: "Eric W. Biederman" To: Linus Torvalds Cc: Vegard Nossum , Kees Cook , linux-kernel@vger.kernel.org, Allen Pais , Brian Mak , Jeff Xu , Roman Kisel , regressions@lists.linux.dev References: <202409160138.7E27F1A55@keescook> Date: Thu, 26 Sep 2024 14:09:21 -0500 In-Reply-To: (Linus Torvalds's message of "Thu, 26 Sep 2024 11:43:22 -0700") Message-ID: <874j625j1a.fsf@email.froward.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1sttsK-00AixJ-HD;;;mid=<874j625j1a.fsf@email.froward.int.ebiederm.org>;;;hst=in02.mta.xmission.com;;;ip=68.227.165.127;;;frm=ebiederm@xmission.com;;;spf=pass X-XM-AID: U2FsdGVkX1+6Y7As3H8gP8wwbRtjmJCtv27Hx7/LaTY= X-Spam-Level: ** X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.4983] * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 1.0 XMSubMetaSx_00 1+ Sexy Words * 1.2 XMSubMetaSxObfu_03 Obfuscated Sexy Noun-People X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: **;Linus Torvalds X-Spam-Relay-Country: X-Spam-Timing: total 307 ms - load_scoreonly_sql: 0.04 (0.0%), signal_user_changed: 8 (2.7%), b_tie_ro: 7 (2.3%), parse: 0.82 (0.3%), extract_message_metadata: 11 (3.5%), get_uri_detail_list: 0.93 (0.3%), tests_pri_-2000: 14 (4.4%), tests_pri_-1000: 2.5 (0.8%), tests_pri_-950: 1.19 (0.4%), tests_pri_-900: 0.95 (0.3%), tests_pri_-90: 95 (31.0%), check_bayes: 94 (30.5%), b_tokenize: 5 (1.8%), b_tok_get_all: 4.8 (1.6%), b_comp_prob: 2.0 (0.7%), b_tok_touch_all: 78 (25.5%), b_finish: 0.82 (0.3%), tests_pri_0: 161 (52.4%), check_dkim_signature: 0.71 (0.2%), check_dkim_adsp: 2.8 (0.9%), poll_dns_idle: 0.90 (0.3%), tests_pri_10: 2.1 (0.7%), tests_pri_500: 8 (2.5%), rewrite_mail: 0.00 (0.0%) Subject: Re: [GIT PULL] execve updates for v6.12-rc1 X-SA-Exim-Connect-IP: 166.70.13.52 X-SA-Exim-Rcpt-To: regressions@lists.linux.dev, romank@linux.microsoft.com, jeffxu@chromium.org, makb@juniper.net, apais@linux.microsoft.com, linux-kernel@vger.kernel.org, kees@kernel.org, vegard.nossum@oracle.com, torvalds@linux-foundation.org X-SA-Exim-Mail-From: ebiederm@xmission.com X-SA-Exim-Scanned: No (on out01.mta.xmission.com); SAEximRunCond expanded to false Linus Torvalds writes: > On Thu, 26 Sept 2024 at 11:29, Vegard Nossum wrote: >> >> # first bad commit: [fb97d2eb542faf19a8725afbd75cbc2518903210] >> binfmt_elf, coredump: Log the reason of the failed core dumps >> >> I have to admit I don't immediately see what's wrong with the patch. > > That commit looks entirely broken. > > I *suspect* that the problem is the crazy "get_task_comm()" in that > takes the task lock inside coredump_report_failure(). > > But honestly, I'm not going to bother even trying to debug this. The > whole notion was broken. People who have problems with truncated > core-files should be looking at their debuggers, not asking the kernel > for help. One of the common causes for coredump truncation is weird interactions between io_uring and the coredump code. (AKA kernel bugs). That is something you can't ask your debugger to tell you. So from 10,000 feet I think the idea is sane. Eric