From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792859156; b=LtOvkIai4xDliQrdJnaHQ0EhluJ5DetP02DdikhiuQHhmnO54x74kJUZ8jad8SM/2pU2 XAq1Q6UXi9DPFHMLxoomAKAio1Wero+LUmS4iMfmVrsAXecaNy/oN+aVTLAOntezgJVVM zvlCjvSoQ0YnxIH4cdCY2FAcpg7/HeJNfL+CVZOInRbKeTCNwXyD3QOQM4ID0l7UR6Qtt s0RwuRZklINZ87YpI/ahmJmKQNO7dN337/o4fQoceuO2qg8jUOiKIPHPTfO7J//2/RoNQ WJ6z+5rs/6pmnFCzKEyXovs36F+CWzNFGtjIFJ0bwyaapm3GabwaVctizsTWXLm8oag== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792859156; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=dX070Ewz6qc5pSc5W0pr0hTHo3VE/xkTK0rhCXuN9c4=; b=1nTN91L5ZYBcCuxIT0Hkj+o0V7+0GJ/SiqADS8y+BvNBTSEkCVTa9q5TWAvNdpi6wvp8 gh+0s4uPXlaM2R36hZNeKqyQMGyK6loys5Fptyn/FV0Fsvt8jUw6lHajMEEw0cYZ4rfa0 Y8o2FRJf1kwfrRRgiP9XKNR9JUOl26SdDu8mPp0wNjdKxXLS4obxKywJbjWH6HmYw//ny u4l7IKypqLwgNZZbZ/9m7dsLb9qmUl2mf3pd+1Df9ftrS2og7btx8TSrGnOby7fCNR+Ka 8V3ba4wvxTOZg7vnunIr1uUUrV9ls8rEWL/a4d1XbgQfjzxLelQuessvWHQ6AsFcrQA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=aIJvUOFu; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 47754606A31D; Sat, 24 Oct 2026 16:25:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=aIJvUOFu Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C27C1F01829; Sat, 24 Oct 2026 16:25:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792859155; bh=dX070Ewz6qc5pSc5W0pr0hTHo3VE/xkTK0rhCXuN9c4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=aIJvUOFu69yVoyLVnTDtLpA6NUyYaSuZCbBYBWypd3if4KXt9g3uJ9Dfvk6421Nmz pcDLj7GVwctBrZ4Sb0tsP4zAWMvvow3MHqC+gQXwpi4R1E2v1gcio34OIuaJrjDvQg WZ64xIhcg7ci8j1xhV8p8lnRmr29Oz+Gf1zOYSp2gBekXhrQ4bpyITiyUSNLAnBdZe LIz7urykTa8m68SnnlIEbQf9TthB8F4Kk6LDbdzBslINg626ugXx8GD0DvI53oR78E qel+BsqM3YAT4fR0P0Nohv6paAicayymf+SHrXAjZj1jjO7dRniED8Nw85JONH00e4 jol3jz5QcZmcw== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Masami Hiramatsu , Shuah Khan Cc: Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH 03/10] tracing/filters: Check CPU bounds before cpumask_test_cpu() in do_filter_cpumask_scalar() Date: Sun, 25 Oct 2026 01:25:52 +0900 Message-ID: <179285915196.466249.7067056297377577459.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <179285912318.466249.7425922682086130057.stgit@devnote2> References: <179285912318.466249.7425922682086130057.stgit@devnote2> User-Agent: StGit/0.19 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit From: Masami Hiramatsu (Google) In parse_pred(), single-CPU cpumask filters are parsed via cpulist_parse(), which checks against nr_cpumask_bits (NR_CPUS). When NR_CPUS > nr_cpu_ids, a user can provide a CPU number where cpu >= nr_cpu_ids. When evaluating such a predicate in filter_pred_cpumask_cpu(), do_filter_cpumask_scalar() calls cpumask_test_cpu(cpu, mask) without checking cpu against nr_cpu_ids. This triggers a WARN_ON_ONCE under CONFIG_DEBUG_PER_CPU_MAPS and causes an out-of-bounds bit test. Check "cpu >= nr_cpu_ids" at the start of do_filter_cpumask_scalar(). When the CPU index is out of bounds, return "op == OP_NE" since an out-of-range CPU is never present in a valid cpumask. Fixes: 38c6f6808389 ("tracing/filters: Further optimise scalar vs cpumask comparison") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_events_filter.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index c2c35b4de85e..69da95f42541 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -695,6 +695,9 @@ do_filter_scalar_cpumask(int op, unsigned int cpu, const struct cpumask *mask) static inline int do_filter_cpumask_scalar(int op, const struct cpumask *mask, unsigned int cpu) { + if (cpu >= nr_cpu_ids) + return op == OP_NE; + switch (op) { case OP_EQ: return cpumask_test_cpu(cpu, mask) &&