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 5F59641A794; Fri, 4 Sep 2026 06:15:25 +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=1788502526; cv=none; b=H71CO5zYkRbRWehY1CwjcnvNh9bXWNK4z8OjMNCzeQdNvpocFIofgAxatKi9ClwNWYm0DuM4tzIPQ93zxHFo/Ex0SWZ4icfgjCalKvgifLVbgf6y1SEjTxhKcmCNZ/BeAu2XUKlAQ19I/nHNuDiYNKK4FwtUmn9RkwCf4SHZlAg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788502526; c=relaxed/simple; bh=WDMuoLlAtJb2vmuhc6l2a0nm2995qIRsQbds3PVr7mQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aMhAOBlZt4Bk8N3Mktawxwaev3mYdH0vKpn9DefhUzY8LsY3t/NkaM1+Y6Zur476WYxVsB9tp3Ut3ODB+jh2c1BayfdDD8+NxFHWjkOc2SI+laEUhZjjsrcZc53mm5Rmi7AmN9N6vVvqXob6zNw/RA4/tEoPHcwOIwgpl52BNrI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HnrtXQ6A; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="HnrtXQ6A" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B82241F00A3D; Fri, 4 Sep 2026 06:15:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788502525; bh=DwHPqImB8hK9MAKmz39NursQ3DH/YfA1SHJlu561xMM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=HnrtXQ6A1smpk30V0GbEO5VuuTq6kR+O0vMztIf+CLgoUpCOtfFZl6R797S+VWgd7 NAIeB8vcsAtunM93GrDj15fV6cVcZ/ZCzZc7o2x0d5JaNZZsUith8LB9mK3gy5mWuD eJ98EaVnaaAGdhIMykBpR1EqcBGAqzPOhihRohYY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sashiko , Vincent Donnefort , Steven Rostedt Subject: [PATCH 6.12 239/403] ring-buffer: Hold cpu_buffer::lock when resizing a subbuf Date: Fri, 4 Sep 2026 07:00:42 +0200 Message-ID: <20260904045740.304638506@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045734.806166532@linuxfoundation.org> References: <20260904045734.806166532@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vincent Donnefort commit 24974bd0da1b47fd56c975533ead50abf754e74d upstream. Because, ring_buffer_subbuf_order_set() can clear cpu_buffer->free_page, hold cpu_buffer->lock to prevent races with ring_buffer_alloc_read_page() and ring_buffer_free_read_page(). Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260813131152.3589632-3-vdonnefort@google.com Fixes: 8e7b58c27b3c ("ring-buffer: Just update the subbuffers when changing their allocation order") Reported-by: Sashiko Closes: https://sashiko.dev/#/patchset/20260810125633.3344684-1-vdonnefort%40google.com # patch 3 Signed-off-by: Vincent Donnefort Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- kernel/trace/ring_buffer.c | 2 ++ 1 file changed, 2 insertions(+) --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -6814,8 +6814,10 @@ int ring_buffer_subbuf_order_set(struct cpu_buffer->nr_pages = cpu_buffer->nr_pages_to_update; cpu_buffer->nr_pages_to_update = 0; + arch_spin_lock(&cpu_buffer->lock); old_free_data_page = cpu_buffer->free_page; cpu_buffer->free_page = NULL; + arch_spin_unlock(&cpu_buffer->lock); rb_head_page_activate(cpu_buffer);