From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 011.lax.mailroute.net (011.lax.mailroute.net [199.89.1.14]) (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 622593E4C88 for ; Thu, 26 Mar 2026 21:41:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774561274; cv=none; b=gRz80b2qHJDHcHJBpMIXlxks6SaDaJg7tlPn9/8l9ign32wYUn+P3sjYohJ4Co+6+6qJPGrC9WnO3+T6NuSdw1HyCNuzMT4lBqv2RE+XAx8ZQBf1T+D9n46OS9GHxAbJINlz5tn9FzZKHxIDKzz9d66SyqysFDqSncaK7jXQuQc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774561274; c=relaxed/simple; bh=nI84xd/DV2qKrIDxyuINMAi9N52Tla73R7GgnDVBIhg=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=JhrOxfWuNg8WnvJx6huQTaBgmbVGKHq9nAXwmFS1q9rYk8i/Lmlv3ydwTPqp6oJ5dwegmRdeuEaIw91CARj0Z5z6OlJCbj1IGF9hq5N5e4Hxe046nEf0/BW8dY+rNalZQEs5YXRzQpWzRM4z9Z3OIg0VdxHnRI+HXgRDAyqg/CY= 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=nLlDCbnZ; arc=none smtp.client-ip=199.89.1.14 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="nLlDCbnZ" Received: from localhost (localhost [127.0.0.1]) by 011.lax.mailroute.net (Postfix) with ESMTP id 4fhcfH4cp2z1XM6Jl; Thu, 26 Mar 2026 21:41:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:content-type:content-type:mime-version :x-mailer:message-id:date:date:subject:subject:from:from :received:received; s=mr01; t=1774561266; x=1777153267; bh=9AVcV QtKehsl/JY+3DCbtSRX3NA3qCRn4URX8RKZ6EQ=; b=nLlDCbnZUM0Fb/vZXNrp9 Sf+Lzr7wuuCw8pMbvpCWAioiyy5f15A8zTMApG5WwDLCFd9en2R2V1kvJqaSXTN6 taTltXwxSs0wD9bq5EV3GrR0L0DF8Dfq5IUAXC57z1lGRs26cmzCZnWkfMt09RW9 /VEWj32WUEHLDtBasDcYQz+JJ7LKOVVYKXbPaR1AIwN299Momsi5chmthLaatijK VNcAD7dd5+uLEjaRjTFLAsVlKckk2O/T14JqvnZDyvNYTRbrJhn4sW+7kSxNnosz pRlPrgR6usxhw3bQkA01Qi/R41ZjuBfXstClBz5wrsJjn4iEAifCtW4rs/ore2ZU g== X-Virus-Scanned: by MailRoute Received: from 011.lax.mailroute.net ([127.0.0.1]) by localhost (011.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id rEN4Kmri5l1r; Thu, 26 Mar 2026 21:41:06 +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 011.lax.mailroute.net (Postfix) with ESMTPSA id 4fhcf82j3lz1XM5kt; Thu, 26 Mar 2026 21:41:04 +0000 (UTC) From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , Bart Van Assche , =?UTF-8?q?Christoph=20B=C3=B6hmwalder?= , Andreas Gruenbacher , Philipp Reisner , Lars Ellenberg , Nathan Chancellor Subject: [PATCH] drbd: Balance RCU calls in drbd_adm_dump_devices() Date: Thu, 26 Mar 2026 14:40:54 -0700 Message-ID: <20260326214054.284593-1-bvanassche@acm.org> X-Mailer: git-send-email 2.53.0.1018.g2bb0e51243-goog Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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. Tested-by: Christoph B=C3=B6hmwalder Reviewed-by: Christoph Hellwig Cc: Andreas Gruenbacher 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 e18fa260a662..1f8ffdf9b24e 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -3443,8 +3443,10 @@ 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; } } @@ -3693,8 +3695,10 @@ 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; }