From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 013.lax.mailroute.net (013.lax.mailroute.net [199.89.1.16]) (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 E72FF3783C5; Mon, 23 Feb 2026 21:51:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771883510; cv=none; b=Q3AXMnkQlqixP6V11mbQruiLEVIqs+O6qG31uZvzGu714KbOwSgH/rSDnPqcwjoyvSu7N8hd8iYTBhFBUIdzBMBoaPJMov5JZK5ggT05Y1e5QV8dVKu2tQMzY6J1uA17/gZDhfcW8R89NjRfsr4S5BvQnaXYGK+gJSyAFf6EiNE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771883510; c=relaxed/simple; bh=zq6bDNiJWYQ+kdpYBR0818FrKLlUyc71kpvByhT0XgQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=a4NhS0z3lNbYQ2R8xtBVt3Uc2uvXuUNJRwkjBTGNu+fKuZ4JA3Z+BqnQUMJf2Fa+0Z6EMn1+Cry82O5yn8vC6KgXdwOEQpvp9r5hP2iRpjq3maCveIMII30myLVGP4l7+yM2MHhZ8BZxf9TVVacwjDlIapvtJmPoL6Gl/Xe8Grs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org; spf=pass smtp.mailfrom=acm.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b=cKtLL9T9; arc=none smtp.client-ip=199.89.1.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=acm.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b="cKtLL9T9" Received: from localhost (localhost [127.0.0.1]) by 013.lax.mailroute.net (Postfix) with ESMTP id 4fKZLr59B2zlh1Wg; Mon, 23 Feb 2026 21:51:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:mime-version:references:in-reply-to :x-mailer:message-id:date:date:subject:subject:from:from :received:received; s=mr01; t=1771883505; x=1774475506; bh=Pw1/H BCffDYtyrpz53JT5DwDWzC+O3+7dDllLLl4yHE=; b=cKtLL9T9CFbpBYQqTm8iF DRgzkhNOHFo37eFhrcSvJndus5zqbK1/ujDF8NejegBHp8eajoc+Ut9jdIttRR+3 T/vAvgPkhZ6GGPibtgAA1bsWNTuLTLCvjxBCSQBuI/nag6jFuFopubSfsFCTuFwq cTLSzXz6UrPFVHlg+jfE/wYF6zKEu7gYMuHU+PtbGPnfRbuhpdNFYop/d0w1ze/r TpWLfyt8/2GItudmfuS2GoYzQ1OB39DJX0X9wuR2cwdM3voRxOyzYZ/EqJ2uo7hr 0VpvUHbOQTe0wwVKfwLMvjzqYFpOvJg48++m9gGfwN9mmSZCcz6J9RltsAJAmyN/ g== X-Virus-Scanned: by MailRoute Received: from 013.lax.mailroute.net ([127.0.0.1]) by localhost (013.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id kw3OZej3YiQK; Mon, 23 Feb 2026 21:51:45 +0000 (UTC) Received: from bvanassche.mtv.corp.google.com (unknown [104.135.180.219]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bvanassche@acm.org) by 013.lax.mailroute.net (Postfix) with ESMTPSA id 4fKZLj5x6hzlfgQH; Mon, 23 Feb 2026 21:51:41 +0000 (UTC) From: Bart Van Assche To: Peter Zijlstra Cc: Ingo Molnar , Will Deacon , Boqun Feng , Waiman Long , linux-kernel@vger.kernel.org, Marco Elver , Christoph Hellwig , Steven Rostedt , Nick Desaulniers , Nathan Chancellor , Kees Cook , Jann Horn , Bart Van Assche , Andreas Gruenbacher , linux-block@vger.kernel.org Subject: [PATCH 03/62] drbd: Balance RCU calls in drbd_adm_dump_devices() Date: Mon, 23 Feb 2026 13:50:18 -0800 Message-ID: <20260223215118.2154194-4-bvanassche@acm.org> X-Mailer: git-send-email 2.53.0.371.g1d285c8824-goog In-Reply-To: <20260223215118.2154194-1-bvanassche@acm.org> References: <20260223215118.2154194-1-bvanassche@acm.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Make drbd_adm_dump_devices() call rcu_read_lock() before rcu_read_unlock() is called. This has been detected by the Clang thread-safety analyzer. Compile-tested only. Cc: Andreas Gruenbacher Cc: linux-block@vger.kernel.org Fixes: a55bbd375d18 ("drbd: Backport the "status" command") Signed-off-by: Bart Van Assche --- drivers/block/drbd/drbd_nl.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index e201f0087a0f..728ecc431b38 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -3378,8 +3378,10 @@ int drbd_adm_dump_devices(struct sk_buff *skb, str= uct netlink_callback *cb) if (resource_filter) { retcode =3D ERR_RES_NOT_KNOWN; resource =3D drbd_find_resource(nla_data(resource_filter)); - if (!resource) + if (!resource) { + rcu_read_lock(); goto put_result; + } cb->args[0] =3D (long)resource; } } @@ -3628,8 +3630,10 @@ int drbd_adm_dump_peer_devices(struct sk_buff *skb= , struct netlink_callback *cb) if (resource_filter) { retcode =3D ERR_RES_NOT_KNOWN; resource =3D drbd_find_resource(nla_data(resource_filter)); - if (!resource) + if (!resource) { + rcu_read_lock(); goto put_result; + } } cb->args[0] =3D (long)resource; }