This is a note to let you know that I've just added the patch titled
nfsd: encoders mustn't use unitialized values in error cases
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nfsd-encoders-mustn-t-use-unitialized-values-in-error-cases.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f961e3f2acae94b727380c0b74e2d3954d0edf79 Mon Sep 17 00:00:00 2001
From: "J. Bruce Fields" <bfields@xxxxxxxxxx>
Date: Fri, 5 May 2017 16:17:57 -0400
Subject: nfsd: encoders mustn't use unitialized values in error cases
From: J. Bruce Fields <bfields@xxxxxxxxxx>
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@xxxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nfsd/nfs4xdr.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -4041,8 +4041,7 @@ 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;
@@ -4059,6 +4058,7 @@ 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) {
/*
@@ -4111,8 +4111,7 @@ 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);
@@ -4135,6 +4134,7 @@ 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);
Patches currently in stable-queue which might be from bfields@xxxxxxxxxx are
queue-4.4/nfsd-check-for-oversized-nfsv2-v3-arguments.patch
queue-4.4/nfsd-encoders-mustn-t-use-unitialized-values-in-error-cases.patch
queue-4.4/nfsd-fix-up-the-supattr_exclcreat-attributes.patch