Re: [PATCH 09/10] nfsd: cap decoded POSIX ACL count to bound sort cost

[Chuck Lever]

[ replaced broken email address for Trond ]

On Thu, May 28, 2026, at 5:55 PM, Jeff Layton wrote:

> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> index c6c50c376b23..5469c6c207ba 100644
> --- a/fs/nfsd/nfs4xdr.c
> +++ b/fs/nfsd/nfs4xdr.c
> @@ -448,6 +448,8 @@ nfsd4_decode_posixacl(struct nfsd4_compoundargs 
> *argp, struct posix_acl **acl)
> 
>  	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
>  		return nfserr_bad_xdr;
> +	if (count > NFS_ACL_MAX_ENTRIES)
> +		return nfserr_resource;

nfserr_resource is consistent with other fattr4 decoders, but
does not make sense here, IMO. A better choice is nfserr_inval.

Rick, any opinion?


>  	*acl = posix_acl_alloc(count, GFP_KERNEL);
>  	if (*acl == NULL)
>
> -- 
> 2.54.0

-- 
Chuck Lever