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Message-Id: <20170523200914.016363356@linuxfoundation.org>
Date: Tue, 23 May 2017 22:09:39 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Ari Kauppi <Ari.Kauppi@...opsys.com>,
Christoph Hellwig <hch@....de>,
"J. Bruce Fields" <bfields@...hat.com>
Subject: [PATCH 4.9 162/164] nfsd: encoders mustnt use unitialized values in error cases
4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: J. Bruce Fields <bfields@...hat.com>
commit f961e3f2acae94b727380c0b74e2d3954d0edf79 upstream.
In error cases, lgp->lg_layout_type may be out of bounds; so we
shouldn't be using it until after the check of nfserr.
This was seen to crash nfsd threads when the server receives a LAYOUTGET
request with a large layout type.
GETDEVICEINFO has the same problem.
Reported-by: Ari Kauppi <Ari.Kauppi@...opsys.com>
Reviewed-by: Christoph Hellwig <hch@....de>
Signed-off-by: J. Bruce Fields <bfields@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
fs/nfsd/nfs4xdr.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -4081,8 +4081,7 @@ nfsd4_encode_getdeviceinfo(struct nfsd4_
struct nfsd4_getdeviceinfo *gdev)
{
struct xdr_stream *xdr = &resp->xdr;
- const struct nfsd4_layout_ops *ops =
- nfsd4_layout_ops[gdev->gd_layout_type];
+ const struct nfsd4_layout_ops *ops;
u32 starting_len = xdr->buf->len, needed_len;
__be32 *p;
@@ -4099,6 +4098,7 @@ nfsd4_encode_getdeviceinfo(struct nfsd4_
/* If maxcount is 0 then just update notifications */
if (gdev->gd_maxcount != 0) {
+ ops = nfsd4_layout_ops[gdev->gd_layout_type];
nfserr = ops->encode_getdeviceinfo(xdr, gdev);
if (nfserr) {
/*
@@ -4151,8 +4151,7 @@ nfsd4_encode_layoutget(struct nfsd4_comp
struct nfsd4_layoutget *lgp)
{
struct xdr_stream *xdr = &resp->xdr;
- const struct nfsd4_layout_ops *ops =
- nfsd4_layout_ops[lgp->lg_layout_type];
+ const struct nfsd4_layout_ops *ops;
__be32 *p;
dprintk("%s: err %d\n", __func__, nfserr);
@@ -4175,6 +4174,7 @@ nfsd4_encode_layoutget(struct nfsd4_comp
*p++ = cpu_to_be32(lgp->lg_seg.iomode);
*p++ = cpu_to_be32(lgp->lg_layout_type);
+ ops = nfsd4_layout_ops[lgp->lg_layout_type];
nfserr = ops->encode_layoutget(xdr, lgp);
out:
kfree(lgp->lg_content);
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