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[23.128.96.18]) by mx.google.com with ESMTP id lt7si1116705ejb.272.2020.08.20.06.30.33; Thu, 20 Aug 2020 06:30:57 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=yMZW4g0F; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727845AbgHTN3J (ORCPT + 99 others); Thu, 20 Aug 2020 09:29:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:45594 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727945AbgHTJdC (ORCPT ); Thu, 20 Aug 2020 05:33:02 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0BE2B22B4E; Thu, 20 Aug 2020 09:33:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597915981; bh=XNfxmt/kbxj2BQBPav5mMIPjAsXbiARPItUl6kns2pw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yMZW4g0FOuNo7IUaTQsDAPvgmz9FCjE4g+kvZUvduQXqjBlDo/kSQpDKlKxk52Wf0 2v7yua7naP/vbujFsZMK2kjHa+bnep7ORQODbzT9c/XyCcAkXgQ7Iv+UfoX2ezSTE8 Q+GoCShCyYewjQ/EuQu+q6lpQ7ujkPsqMnc7xjcM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeffrey Mitchell , Trond Myklebust , Sasha Levin Subject: [PATCH 5.8 203/232] nfs: Fix getxattr kernel panic and memory overflow Date: Thu, 20 Aug 2020 11:20:54 +0200 Message-Id: <20200820091622.642231836@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200820091612.692383444@linuxfoundation.org> References: <20200820091612.692383444@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jeffrey Mitchell [ Upstream commit b4487b93545214a9db8cbf32e86411677b0cca21 ] Move the buffer size check to decode_attr_security_label() before memcpy() Only call memcpy() if the buffer is large enough Fixes: aa9c2669626c ("NFS: Client implementation of Labeled-NFS") Signed-off-by: Jeffrey Mitchell [Trond: clean up duplicate test of label->len != 0] Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/nfs4proc.c | 2 -- fs/nfs/nfs4xdr.c | 6 +++++- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 2e2dac29a9e91..45e0585e0667c 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -5845,8 +5845,6 @@ static int _nfs4_get_security_label(struct inode *inode, void *buf, return ret; if (!(fattr.valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL)) return -ENOENT; - if (buflen < label.len) - return -ERANGE; return 0; } diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index 47817ef0aadb1..4e0d8a3b89b67 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -4166,7 +4166,11 @@ static int decode_attr_security_label(struct xdr_stream *xdr, uint32_t *bitmap, return -EIO; if (len < NFS4_MAXLABELLEN) { if (label) { - memcpy(label->label, p, len); + if (label->len) { + if (label->len < len) + return -ERANGE; + memcpy(label->label, p, len); + } label->len = len; label->pi = pi; label->lfs = lfs; -- 2.25.1