From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out03.mta.xmission.com (out03.mta.xmission.com [166.70.13.233]) (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 503253002DD; Wed, 24 Jun 2026 15:54:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=166.70.13.233 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782316470; cv=none; b=JvctE/nztQJBglGw/ZXF3ULD5sf2m4A/DjV5LLVRJ1Dc5x1l5YtCpd2ugSDlr/7tgaqQhHnbFoJWUG1dZTqiCWIk52N2yvmPuK51tL7KGf+q7iOdmiquQNs1rSuQn9c4kCheairuaJnbe2PNjL/Gtk2Z192EU827iOML5PffYNw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782316470; c=relaxed/simple; bh=xh7ViXnNgYwHC7qNeGeR9ecHxFs4hpAP5kSmM5JL+Vw=; h=From:To:Cc:In-Reply-To:References:Date:Message-ID:MIME-Version: Content-Type:Subject; b=Bp4UuKV7NGxkBHLfXcW5yTorjaznV0KI6bPYhEgVn+kfxfezdZJiOz6uCN7qRf2xUudek9RWvcFtLw7FOa4zHquUZ09YA3thGQbT+Q3+jmn5ghyj0G5NY6/11xBGH4cvRCXFDNcCGDdl77bTQ5piXMkUz/VaUgTZoMRVkUtFJlY= 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; dkim=pass (1024-bit key) header.d=xmission.com header.i=@xmission.com header.b=GGxBrXow; arc=none smtp.client-ip=166.70.13.233 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 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=xmission.com header.i=@xmission.com header.b="GGxBrXow" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=simple/simple; d=xmission.com; s=xmission; h=Subject:Content-Type:MIME-Version:Message-ID:Date:References: In-Reply-To:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=xh7ViXnNgYwHC7qNeGeR9ecHxFs4hpAP5kSmM5JL+Vw=; b=GGxBrXowz7rXY1LiITAIg4lPTC YdXZosxxfln9aFYpwvraz7YZcUidW/vs744LrhfzZhTw6OyNOBuz7a5qSGv3SCtcAeq/As3YKsTb+ 00cenxSa3qtJxxhLi9EkuC96wjmgOlWVuVKkvgiH/gKKTYkSycrdcDejizLahl74m6UQ=; Received: from in02.mta.xmission.com ([166.70.13.52]:42798) by out03.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1wcPYC-001JQQ-Uw; Wed, 24 Jun 2026 09:30:04 -0600 Received: from ip72-198-198-28.om.om.cox.net ([72.198.198.28]:59284 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 1wcPYC-00GnQt-3S; Wed, 24 Jun 2026 09:30:04 -0600 From: "Eric W. Biederman" To: Oleg Nesterov Cc: Bradley Morgan , Christian Brauner , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Andrew Morton , Peter Zijlstra , Marco Elver , Aleksandr Nogikh , Thomas Gleixner , Adrian Huang , Kexin Sun , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, stable@vger.kernel.org In-Reply-To: (Oleg Nesterov's message of "Tue, 23 Jun 2026 13:37:09 +0200") References: <20260622164029.11474-1-include@grrlz.net> <86a8857d58d43ee26a8b365b837fd24830343494.1782159692.git.include@grrlz.net> Date: Wed, 24 Jun 2026 10:29:59 -0500 Message-ID: <87bjd0c5xk.fsf@email.froward.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1wcPYC-00GnQt-3S;;;mid=<87bjd0c5xk.fsf@email.froward.int.ebiederm.org>;;;hst=in02.mta.xmission.com;;;ip=72.198.198.28;;;frm=ebiederm@xmission.com;;;spf=pass X-XM-AID: U2FsdGVkX19lMRvGX1KD9Qluxwju7Bauekh91GYrANI= X-Spam-Level: X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.1 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.4493] * 0.7 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa07 1397; Body=1 Fuz1=1 Fuz2=1] * 1.0 T_XMDrugObfuBody_08 obfuscated drug references X-Spam-DCC: XMission; sa07 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Oleg Nesterov X-Spam-Relay-Country: X-Spam-Timing: total 401 ms - load_scoreonly_sql: 0.06 (0.0%), signal_user_changed: 10 (2.5%), b_tie_ro: 9 (2.2%), parse: 1.02 (0.3%), extract_message_metadata: 3.3 (0.8%), get_uri_detail_list: 1.20 (0.3%), tests_pri_-2000: 3.4 (0.8%), tests_pri_-1000: 3.0 (0.8%), tests_pri_-950: 1.17 (0.3%), tests_pri_-900: 0.97 (0.2%), tests_pri_-90: 111 (27.7%), check_bayes: 110 (27.4%), b_tokenize: 7 (1.7%), b_tok_get_all: 7 (1.7%), b_comp_prob: 2.1 (0.5%), b_tok_touch_all: 91 (22.8%), b_finish: 0.76 (0.2%), tests_pri_0: 246 (61.3%), check_dkim_signature: 0.54 (0.1%), check_dkim_adsp: 2.6 (0.7%), poll_dns_idle: 0.82 (0.2%), tests_pri_10: 1.94 (0.5%), tests_pri_500: 11 (2.8%), rewrite_mail: 0.00 (0.0%) Subject: Re: [PATCH v2 1/2] signal: avoid shared siginfo namespace rewrites X-SA-Exim-Connect-IP: 166.70.13.52 X-SA-Exim-Rcpt-To: stable@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, kexinsun@smail.nju.edu.cn, adrianhuang0701@gmail.com, tglx@kernel.org, nogikh@google.com, elver@google.com, peterz@infradead.org, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, mhiramat@kernel.org, rostedt@goodmis.org, brauner@kernel.org, include@grrlz.net, oleg@redhat.com X-SA-Exim-Mail-From: ebiederm@xmission.com X-SA-Exim-Scanned: No (on out03.mta.xmission.com); SAEximRunCond expanded to false Oleg Nesterov writes: > Add Eric. > > OK, I agree, it seems we need a simple fix. > > Acked-by: Oleg Nesterov > > ------------------------------------------------------------------------- > But let me add some "offtopic" notes... Why do we actually need this fix? > > kill_something_info(). But at first glance sys_kill/kill_something_info > can simply use SEND_SIG_NOINFO? If yes, this makes sense anyway, I will > re-check... > > do_pidfd_send_signal(PIDFD_SIGNAL_PROCESS_GROUP) allows to call > kill_pgrp_info() if si_code < 0... Not that I think this would be better, > but we could move this "rewrite" logic into __kill_pgrp_info()... > > Anything else needs this change? Most probably yes, but after the quick > grep I don't see other group senders with !is_si_special(info). > > Eric, what do you think? So I think tracing the basic kill syscall is interesting. It uses an explicit siginfo. It does that so it can choose between setting si_code to SI_TKILL and SI_USER. If the signal number is -1 it sends to every process in the system (or at least the pid namespace). That will require translation. So either we need to add another special siginfo value to handle SI_TKILL, or we need to fix this the way that was suggested. I suspect just fixing send_signal_locked looks the easiest, especially if you make the siginfo parameter const. It would likely help to have a self test that detects the problem before this is fixed and passes afterwards so we have some chance of detecting if someone makes a similar mistake in the future. Eric