From nobody Thu Apr 9 04:43:20 2026 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 C9693C4332F for ; Mon, 14 Nov 2022 09:10:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235953AbiKNJK1 (ORCPT ); Mon, 14 Nov 2022 04:10:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56922 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235889AbiKNJKT (ORCPT ); Mon, 14 Nov 2022 04:10:19 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A7BACEA; Mon, 14 Nov 2022 01:10:18 -0800 (PST) Date: Mon, 14 Nov 2022 09:10:15 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1668417016; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=flibQ14geqBtHOZ1ZdsLp9+eqkvU+IBQCYejrpRxmlM=; b=Fu+1KDPBwhpGK4tizlig/AS7Wz+jSvcjnMilQaXRuO9iR/QfWYnLKMqVlTuBwL5WneQfn7 P47j0H3kZAXNBJyx69qzQBR34IbvfE1F4Zg3ophy1wjYJTnGfpGcV1E6q2GP8ZhdgiW0NE dKMxG99dDoeM2spqVhajubawLMQJHkO8qdYOFZetZZgvZ75Eu9HLrnqB7VV8+J01SdDVVU MU9/eB0G+kdZDwBU3jN2HLzKrBkVDXI4iLMFVvEDY+qzxbymW0X0nf6kgBnZU7cgXxu2hP 088njtygSn9D+hoXsMuDhZFg0OrnRU9iPYs/CeOjfJLLEQPZn2yejWU1KpnPQw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1668417016; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=flibQ14geqBtHOZ1ZdsLp9+eqkvU+IBQCYejrpRxmlM=; b=WCbXEb6IhTvLN7iLukqTlSpjzhTB6BIxIW9yy4uY77MgUwd2wPzhgnG8AsmT0sKxcG1fbF p3ZNB95x7oKw0WCQ== From: "tip-bot2 for Mathieu Desnoyers" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/urgent] rseq: Use pr_warn_once() when deprecated/unknown ABI flags are encountered Cc: Mark Rutland , Mathieu Desnoyers , "Peter Zijlstra (Intel)" , "Paul E. McKenney" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20221102130635.7379-1-mathieu.desnoyers@efficios.com> References: <20221102130635.7379-1-mathieu.desnoyers@efficios.com> MIME-Version: 1.0 Message-ID: <166841701553.4906.1749822907973997217.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the sched/urgent branch of tip: Commit-ID: 448dca8c88755b768552e19bd1618be34ef6d1ff Gitweb: https://git.kernel.org/tip/448dca8c88755b768552e19bd1618be34= ef6d1ff Author: Mathieu Desnoyers AuthorDate: Wed, 02 Nov 2022 09:06:35 -04:00 Committer: Peter Zijlstra CommitterDate: Mon, 14 Nov 2022 09:58:32 +01:00 rseq: Use pr_warn_once() when deprecated/unknown ABI flags are encountered These commits use WARN_ON_ONCE() and kill the offending processes when deprecated and unknown flags are encountered: commit c17a6ff93213 ("rseq: Kill process when unknown flags are encountered= in ABI structures") commit 0190e4198e47 ("rseq: Deprecate RSEQ_CS_FLAG_NO_RESTART_ON_* flags") The WARN_ON_ONCE() triggered by userspace input prevents use of Syzkaller to fuzz the rseq system call. Replace this WARN_ON_ONCE() by pr_warn_once() messages which contain actually useful information. Reported-by: Mark Rutland Signed-off-by: Mathieu Desnoyers Signed-off-by: Peter Zijlstra (Intel) Acked-by: Mark Rutland Acked-by: Paul E. McKenney Link: https://lkml.kernel.org/r/20221102130635.7379-1-mathieu.desnoyers@eff= icios.com --- kernel/rseq.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/kernel/rseq.c b/kernel/rseq.c index bda8175..d38ab94 100644 --- a/kernel/rseq.c +++ b/kernel/rseq.c @@ -171,12 +171,27 @@ static int rseq_get_rseq_cs(struct task_struct *t, st= ruct rseq_cs *rseq_cs) return 0; } =20 +static bool rseq_warn_flags(const char *str, u32 flags) +{ + u32 test_flags; + + if (!flags) + return false; + test_flags =3D flags & RSEQ_CS_NO_RESTART_FLAGS; + if (test_flags) + pr_warn_once("Deprecated flags (%u) in %s ABI structure", test_flags, st= r); + test_flags =3D flags & ~RSEQ_CS_NO_RESTART_FLAGS; + if (test_flags) + pr_warn_once("Unknown flags (%u) in %s ABI structure", test_flags, str); + return true; +} + static int rseq_need_restart(struct task_struct *t, u32 cs_flags) { u32 flags, event_mask; int ret; =20 - if (WARN_ON_ONCE(cs_flags & RSEQ_CS_NO_RESTART_FLAGS) || cs_flags) + if (rseq_warn_flags("rseq_cs", cs_flags)) return -EINVAL; =20 /* Get thread flags. */ @@ -184,7 +199,7 @@ static int rseq_need_restart(struct task_struct *t, u32= cs_flags) if (ret) return ret; =20 - if (WARN_ON_ONCE(flags & RSEQ_CS_NO_RESTART_FLAGS) || flags) + if (rseq_warn_flags("rseq", flags)) return -EINVAL; =20 /*