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authorJ. Bruce Fields <bfields@redhat.com>2017-05-05 20:17:57 (GMT)
committerJ. Bruce Fields <bfields@redhat.com>2017-05-10 18:25:19 (GMT)
commitf961e3f2acae94b727380c0b74e2d3954d0edf79 (patch)
treede0fd2594a2efeaa34bdefff2880ef9824975cf3
parentb550a32e60a4941994b437a8d662432a486235a5 (diff)
downloadlinux-f961e3f2acae94b727380c0b74e2d3954d0edf79.tar.gz
linux-f961e3f2acae94b727380c0b74e2d3954d0edf79.tar.xz
nfsd: encoders mustn't use unitialized values in error cases
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@synopsys.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
-rw-r--r--fs/nfsd/nfs4xdr.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 33017d6..8e9652f 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -4119,8 +4119,7 @@ nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
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;
@@ -4137,6 +4136,7 @@ nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
/* 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) {
/*
@@ -4189,8 +4189,7 @@ nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
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);
@@ -4213,6 +4212,7 @@ nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
*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);