nfsd: make nfs4xdr WRITEMEM safe against zero count

[safe/jmp/linux-2.6] / fs / nfsd / nfs4xdr.c

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index c513bbd..9547ab6 100644 (file)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1201,7 +1201,7 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
        *p++ = htonl((u32)((n) >> 32));                         \
        *p++ = htonl((u32)(n));                                 \
 } while (0)
-#define WRITEMEM(ptr,nbytes)     do {                          \
+#define WRITEMEM(ptr,nbytes)     do if (nbytes > 0) {          \
        *(p + XDR_QUADLEN(nbytes) -1) = 0;                      \
        memcpy(p, ptr, nbytes);                                 \
        p += XDR_QUADLEN(nbytes);                               \