From patchwork Thu Dec 21 15:09:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13502242 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 9B6DD360BC for ; Thu, 21 Dec 2023 15:09:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="MyDQAklb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1703171377; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=3Le+gA8/eXxjZEgbRfZ5PEeY/UYos/EZllx1bsLSYMw=; b=MyDQAklbQdgvuu5GlVku2nXjN7d5EE42pN8Fy0QAoEKM8CQrAc8AWK18CNo4pHJrKeayal 4uF68yPnlEHJyowRuSrFL3btkdTiU27bFPAgTpNj+ct5xi+YZZx/89WLXbxaX1LofK2jzv DQPHF61CzbS9RWY3HT+DIAb52YkFPSk= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-394-cLcz9jdNOGCqSLHoOXu-xQ-1; Thu, 21 Dec 2023 10:09:33 -0500 X-MC-Unique: cLcz9jdNOGCqSLHoOXu-xQ-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (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) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4E5643813BD2; Thu, 21 Dec 2023 15:09:33 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.39.195.169]) by smtp.corp.redhat.com (Postfix) with ESMTP id E34D7492BC6; Thu, 21 Dec 2023 15:09:31 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells To: torvalds@linux-foundation.org cc: Anastasia Belova , Marc Dionne , dhowells@redhat.com, linux-afs@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, lvc-project@linuxtesting.org Subject: [PATCH] afs: Fix overwriting of result of DNS query Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-ID: <1842327.1703171371.1@warthog.procyon.org.uk> Date: Thu, 21 Dec 2023 15:09:31 +0000 Message-ID: <1842328.1703171371@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.9 Hi Linus, Could you apply this fix, please? Thanks, David --- In afs_update_cell(), ret is the result of the DNS lookup and the errors are to be handled by a switch - however, the value gets clobbered in between by setting it to -ENOMEM in case afs_alloc_vlserver_list() fails. Fix this by moving the setting of -ENOMEM into the error handling for OOM failure. Further, only do it if we don't have an alternative error to return. Found by Linux Verification Center (linuxtesting.org) with SVACE. Based on a patch from Anastasia Belova[1]. Fixes: d5c32c89b208 ("afs: Fix cell DNS lookup") Signed-off-by: David Howells Reviewed-by: Jeffrey Altman cc: Anastasia Belova cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: lvc-project@linuxtesting.org Link: https://lore.kernel.org/r/20231221085849.1463-1-abelova@astralinux.ru/ [1] Link: https://lore.kernel.org/r/1700862.1703168632@warthog.procyon.org.uk/ # v1 --- fs/afs/cell.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/afs/cell.c b/fs/afs/cell.c index 988c2ac7cece..926cb1188eba 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -409,10 +409,12 @@ static int afs_update_cell(struct afs_cell *cell) if (ret == -ENOMEM) goto out_wake; - ret = -ENOMEM; vllist = afs_alloc_vlserver_list(0); - if (!vllist) + if (!vllist) { + if (ret >= 0) + ret = -ENOMEM; goto out_wake; + } switch (ret) { case -ENODATA: