From d6e0c42ccbb489d73ebc3973583474257a028d66 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Tue, 4 Dec 2012 18:25:10 -0500 Subject: nfsd4: fix oops on unusual readlike compound commit d5f50b0c290431c65377c4afa1c764e2c3fe5305 upstream. 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. Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfs4xdr.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index f91d589..ecdd18a 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2682,11 +2682,16 @@ 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; } @@ -2734,6 +2739,8 @@ 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++]); @@ -2783,6 +2790,8 @@ 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(8); /* verifier */ savep = p; -- cgit v1.1