From 5d6031ca742f9f07b9c9d9322538619f3bd155ac Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Thu, 17 Jul 2014 16:20:39 -0400 Subject: nfsd4: zero op arguments beyond the 8th compound op The first 8 ops of the compound are zeroed since they're a part of the argument that's zeroed by the memset(rqstp->rq_argp, 0, procp->pc_argsize); in svc_process_common(). But we handle larger compounds by allocating the memory on the fly in nfsd4_decode_compound(). Other than code recently fixed by 01529e3f8179 "NFSD: Fix memory leak in encoding denied lock", I don't know of any examples of code depending on this initialization. But it definitely seems possible, and I'd rather be safe. Compounds this long are unusual so I'm much more worried about failure in this poorly tested cases than about an insignificant performance hit. Signed-off-by: J. Bruce Fields diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 01023a5..628b430 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -1635,7 +1635,7 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp) goto xdr_error; if (argp->opcnt > ARRAY_SIZE(argp->iops)) { - argp->ops = kmalloc(argp->opcnt * sizeof(*argp->ops), GFP_KERNEL); + argp->ops = kzalloc(argp->opcnt * sizeof(*argp->ops), GFP_KERNEL); if (!argp->ops) { argp->ops = argp->iops; dprintk("nfsd: couldn't allocate room for COMPOUND\n"); -- cgit v0.10.2