From: Chuck Lever Date: Mon, 29 Sep 2025 16:53:40 +0000 (-0400) Subject: NFSD: Define actions for the new time_deleg FATTR4 attributes X-Git-Tag: v6.18-rc4~26^2~3 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4f76435fd517981f01608678c06ad9718a86ee98;p=thirdparty%2Fkernel%2Flinux.git NFSD: Define actions for the new time_deleg FATTR4 attributes NFSv4 clients won't send legitimate GETATTR requests for these new attributes because they are intended to be used only with CB_GETATTR and SETATTR. But NFSD has to do something besides crashing if it ever sees a GETATTR request that queries these attributes. RFC 8881 Section 18.7.3 states: > The server MUST return a value for each attribute that the client > requests if the attribute is supported by the server for the > target file system. If the server does not support a particular > attribute on the target file system, then it MUST NOT return the > attribute value and MUST NOT set the attribute bit in the result > bitmap. The server MUST return an error if it supports an > attribute on the target but cannot obtain its value. In that case, > no attribute values will be returned. Further, RFC 9754 Section 5 states: > These new attributes are invalid to be used with GETATTR, VERIFY, > and NVERIFY, and they can only be used with CB_GETATTR and SETATTR > by a client holding an appropriate delegation. Thus there does not appear to be a specific server response mandated by specification. Taking the guidance that querying these attributes via GETATTR is "invalid", NFSD will return nfserr_inval, failing the request entirely. Reported-by: Robert Morris Closes: https://lore.kernel.org/linux-nfs/7819419cf0cb50d8130dc6b747765d2b8febc88a.camel@kernel.org/T/#t Fixes: 51c0d4f7e317 ("nfsd: add support for FATTR4_OPEN_ARGUMENTS") Cc: stable@vger.kernel.org Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever --- diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index c0a3c6a7c8bb7..8f5ee3014abc8 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2939,6 +2939,12 @@ struct nfsd4_fattr_args { typedef __be32(*nfsd4_enc_attr)(struct xdr_stream *xdr, const struct nfsd4_fattr_args *args); +static __be32 nfsd4_encode_fattr4__inval(struct xdr_stream *xdr, + const struct nfsd4_fattr_args *args) +{ + return nfserr_inval; +} + static __be32 nfsd4_encode_fattr4__noop(struct xdr_stream *xdr, const struct nfsd4_fattr_args *args) { @@ -3560,6 +3566,8 @@ static const nfsd4_enc_attr nfsd4_enc_fattr4_encode_ops[] = { [FATTR4_MODE_UMASK] = nfsd4_encode_fattr4__noop, [FATTR4_XATTR_SUPPORT] = nfsd4_encode_fattr4_xattr_support, + [FATTR4_TIME_DELEG_ACCESS] = nfsd4_encode_fattr4__inval, + [FATTR4_TIME_DELEG_MODIFY] = nfsd4_encode_fattr4__inval, [FATTR4_OPEN_ARGUMENTS] = nfsd4_encode_fattr4_open_arguments, };