4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: J. Bruce Fields <[email protected]> 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 <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Signed-off-by: J. Bruce Fields <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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);
