Commit d5f50b0c authored by J. Bruce Fields's avatar J. Bruce Fields
Browse files

nfsd4: fix oops on unusual readlike compound 



If the argument and reply together exceed the maximum payload size, then
a reply with a read-like operation can overlow the rq_pages array.

Cc: stable@kernel.org
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 9b3234b9

fs/nfsd/nfs4xdr.c

+10 −1
Original line number Diff line number Diff line
@@ -2925,11 +2925,16 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr, 
	len = maxcount;

	v = 0;

	while (len > 0) {

		pn = resp->rqstp->rq_resused++;

		pn = resp->rqstp->rq_resused;

		if (!resp->rqstp->rq_respages[pn]) { /* ran out of pages */

			maxcount -= len;

			break;

		}

		resp->rqstp->rq_vec[v].iov_base =

			page_address(resp->rqstp->rq_respages[pn]);

		resp->rqstp->rq_vec[v].iov_len =

			len < PAGE_SIZE ? len : PAGE_SIZE;

		resp->rqstp->rq_resused++;

		v++;

		len -= PAGE_SIZE;

	}
@@ -2975,6 +2980,8 @@ nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd 
		return nfserr;

	if (resp->xbuf->page_len)

		return nfserr_resource;

	if (!resp->rqstp->rq_respages[resp->rqstp->rq_resused])

		return nfserr_resource;



	page = page_address(resp->rqstp->rq_respages[resp->rqstp->rq_resused++]);
@@ -3024,6 +3031,8 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4 
		return nfserr;

	if (resp->xbuf->page_len)

		return nfserr_resource;

	if (!resp->rqstp->rq_respages[resp->rqstp->rq_resused])

		return nfserr_resource;



	RESERVE_SPACE(NFS4_VERIFIER_SIZE);

	savep = p;