From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 51664386C0A for ; Sun, 13 Sep 2026 17:17:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789319848; cv=none; b=I7CMp3GT/oU190A3XigVxtCx64J9qlsQ8Ym+mlVHGZ87ZL+Uj+ocw/Mvn907NA1CKmijKgPRA6ixtMWkrgpSaajvlIwd7FPsh+S0jDFEcSNUtkY/DxRCHCU4krZPVYkzv8QhWh360f18iywW4sSA4+CN4VHRBcQVQDh3KzUZxQk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789319848; c=relaxed/simple; bh=MUjzs0JwgrAacduebmV4M1RxAHd/0cc3cjIxj/6R2kQ=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=NC8qJjLYni8pamNTh5TZUsp0kv7ixplPuofIZtXFlcwDNBqaHCY+umTZp5UnBEnnHE0orRal0RK9F4Q0EZZ1mMzamaqm0/OhyYdCgYMpdWMPKX3tySL+g9BrgYN+LsJkwwufRtTzf5YkcMblPZTdrFKs7qMyzEaVRHZA2IKsKx8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DtdVdDye; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DtdVdDye" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 364DC1F0089B; Sun, 13 Sep 2026 17:17:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789319844; bh=b4nohpa6rw6Jtm0z0TblGaxx+Ubk55nsfmnZONif07o=; h=Date:From:To:Cc:Subject:References; b=DtdVdDyeM/+izgEEtPjtRaGuNjb7f6ysdebkfIbHu4cDxWqr0Wkle+qDEvXp655fP t2NX3YOwMvm2GyUD4Y9mME7SUZZUnhEKUv4VTSG7I7CNDbTveV0ttV98kzPHJUXPFq YJnRbFCxF3j/VdvdEjYCRqSMjza8M8qxZmBtUtpgbmjt0WNU7ewdrEFJaIXQhj/nia NQQLfLZvtgQWXrXq3q77+R9zdn2rrLDWjmAT1M5kg1UIo90gbWMHFIKs4diRwysGpb x79Hj7piBdM9Q52OqqRTFM470RUlM59BbtSrFVc+IXw1GHAvdp0K4/rJWHYeK635mI NW7u8JBjgedjg== Received: from rostedt by gandalf with local (Exim 4.99.4) (envelope-from ) id 1x5nqs-0000000AQai-1IjW; Sun, 13 Sep 2026 13:18:50 -0400 Message-ID: <20260913171850.115977878@kernel.org> User-Agent: quilt/0.69 Date: Sun, 13 Sep 2026 13:18:03 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Vincent Donnefort Subject: [for-linus][PATCH 4/5] tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing References: <20260913171759.469375546@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: Vincent Donnefort The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. Return SIZE_MAX from trace_buffer_desc_size() on nr_page_va overflow. Link: https://patch.msgid.link/20260911193937.602202-3-vdonnefort@google.com Fixes: 2e67fabd8b77 ("ring-buffer: Introduce ring-buffer remotes") Signed-off-by: Vincent Donnefort Signed-off-by: Steven Rostedt --- include/linux/ring_buffer.h | 4 ++++ kernel/trace/trace_remote.c | 6 +++++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index 11bffb6a142d..eac3e9080c3c 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -295,6 +295,10 @@ static inline size_t trace_buffer_desc_size(size_t buffer_size, unsigned int nr_ unsigned long nr_pages = __calc_nr_pages_ring_buffer_desc(buffer_size); struct ring_buffer_desc *rbdesc; + /* Capped by ring_buffer_desc::nr_page_va */ + if (nr_pages > UINT_MAX) + return SIZE_MAX; + return size_add(offsetof(struct trace_buffer_desc, __data), size_mul(nr_cpus, struct_size(rbdesc, page_va, nr_pages))); } diff --git a/kernel/trace/trace_remote.c b/kernel/trace/trace_remote.c index c17902e42ef1..2d5bc423efca 100644 --- a/kernel/trace/trace_remote.c +++ b/kernel/trace/trace_remote.c @@ -980,9 +980,12 @@ int trace_remote_alloc_buffer(struct trace_buffer_desc *desc, size_t desc_size, const struct cpumask *cpumask) { size_t min_desc_size = trace_buffer_desc_size(buffer_size, cpumask_weight(cpumask)); - unsigned int nr_pages = __calc_nr_pages_ring_buffer_desc(buffer_size); struct ring_buffer_desc *rb_desc; int cpu, ret = -ENOMEM; + unsigned int nr_pages; + + if (min_desc_size == SIZE_MAX) + return -E2BIG; if (desc_size < min_desc_size) return -EINVAL; @@ -991,6 +994,7 @@ int trace_remote_alloc_buffer(struct trace_buffer_desc *desc, size_t desc_size, desc->struct_len = min_desc_size; rb_desc = __first_ring_buffer_desc(desc); + nr_pages = __calc_nr_pages_ring_buffer_desc(buffer_size); for_each_cpu(cpu, cpumask) { unsigned int id; -- 2.53.0