diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index 7e4bb0af24d7..43fb360784b7 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -369,7 +369,7 @@ int nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd3_writeargs *args) { - unsigned int len, v, hdr; + unsigned int len, v, hdr, dlen; u32 max_blocksize = svc_max_payload(rqstp); if (!(p = decode_fh(p, &args->fh)) @@ -379,18 +379,47 @@ nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p, args->count = ntohl(*p++); args->stable = ntohl(*p++); len = args->len = ntohl(*p++); - - hdr = (void*)p - rqstp->rq_arg.head[0].iov_base; - if (rqstp->rq_arg.len < hdr || - rqstp->rq_arg.len - hdr < len) + /* + * The count must equal the amount of data passed. + */ + if (args->count != args->len) return 0; + /* + * Check to make sure that we got the right number of + * bytes. + * + * If more than one page was used, then compute the length + * of the data in the request as the total size of the + * request minus the transport protocol headers minus the + * RPC protocol headers minus the NFS protocol fields + * already consumed. If the request fits into a single + * page, then compete the length of the data as the size + * of the NFS portion of the request minus the NFS + * protocol fields already consumed. + */ + hdr = (void*)p - rqstp->rq_arg.head[0].iov_base; + if (rqstp->rq_respages != rqstp->rq_pages + 1) { + dlen = rqstp->rq_arg.len - + (PAGE_SIZE - rqstp->rq_arg.head[0].iov_len) - hdr; + } else { + dlen = rqstp->rq_arg.head[0].iov_len - hdr; + } + /* + * Round the length of the data which was specified up to + * the next multiple of XDR units and then compare that + * against the length which was actually received. + */ + if (dlen != ((len + 3) & ~0x3)) + return 0; + + if (args->count > max_blocksize) { + args->count = max_blocksize; + len = args->len = max_blocksize; + } rqstp->rq_vec[0].iov_base = (void*)p; rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr; - - if (len > max_blocksize) - len = max_blocksize; - v= 0; + v = 0; while (len > rqstp->rq_vec[v].iov_len) { len -= rqstp->rq_vec[v].iov_len; v++; @@ -398,9 +427,8 @@ nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p, rqstp->rq_vec[v].iov_len = PAGE_SIZE; } rqstp->rq_vec[v].iov_len = len; - args->vlen = v+1; - - return args->count == args->len && rqstp->rq_vec[0].iov_len > 0; + args->vlen = v + 1; + return 1; } int diff --git a/fs/nfsd/nfsxdr.c b/fs/nfsd/nfsxdr.c index 0c24b9e24fe8..6035e03655c6 100644 --- a/fs/nfsd/nfsxdr.c +++ b/fs/nfsd/nfsxdr.c @@ -284,8 +284,9 @@ int nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_writeargs *args) { - unsigned int len; + unsigned int len, hdr, dlen; int v; + if (!(p = decode_fh(p, &args->fh))) return 0; @@ -293,11 +294,42 @@ nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p, args->offset = ntohl(*p++); /* offset */ p++; /* totalcount */ len = args->len = ntohl(*p++); - rqstp->rq_vec[0].iov_base = (void*)p; - rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - - (((void*)p) - rqstp->rq_arg.head[0].iov_base); + /* + * The protocol specifies a maximum of 8192 bytes. + */ if (len > NFSSVC_MAXBLKSIZE_V2) - len = NFSSVC_MAXBLKSIZE_V2; + return 0; + + /* + * Check to make sure that we got the right number of + * bytes. + * + * If more than one page was used, then compute the length + * of the data in the request as the total size of the + * request minus the transport protocol headers minus the + * RPC protocol headers minus the NFS protocol fields + * already consumed. If the request fits into a single + * page, then compete the length of the data as the size + * of the NFS portion of the request minus the NFS + * protocol fields already consumed. + */ + hdr = (void*)p - rqstp->rq_arg.head[0].iov_base; + if (rqstp->rq_respages != rqstp->rq_pages + 1) { + dlen = rqstp->rq_arg.len - + (PAGE_SIZE - rqstp->rq_arg.head[0].iov_len) - hdr; + } else { + dlen = rqstp->rq_arg.head[0].iov_len - hdr; + } + /* + * Round the length of the data which was specified up to + * the next multiple of XDR units and then compare that + * against the length which was actually received. + */ + if (dlen != ((len + 3) & ~0x3)) + return 0; + + rqstp->rq_vec[0].iov_base = (void*)p; + rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr; v = 0; while (len > rqstp->rq_vec[v].iov_len) { len -= rqstp->rq_vec[v].iov_len; @@ -306,8 +338,8 @@ nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p, rqstp->rq_vec[v].iov_len = PAGE_SIZE; } rqstp->rq_vec[v].iov_len = len; - args->vlen = v+1; - return rqstp->rq_vec[0].iov_len > 0; + args->vlen = v + 1; + return 1; } int