From fcb8d118e149255d28be2d799ddbb1c63d015b82 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Mon, 17 Nov 2025 11:00:49 -0500 Subject: [PATCH] NFSD: Clear SECLABEL in the suppattr_exclcreat bitmap commit 27d17641cacfedd816789b75d342430f6b912bd2 upstream. >From RFC 8881: 5.8.1.14. Attribute 75: suppattr_exclcreat > The bit vector that would set all REQUIRED and RECOMMENDED > attributes that are supported by the EXCLUSIVE4_1 method of file > creation via the OPEN operation. The scope of this attribute > applies to all objects with a matching fsid. There's nothing in RFC 8881 that states that suppattr_exclcreat is or is not allowed to contain bits for attributes that are clear in the reported supported_attrs bitmask. But it doesn't make sense for an NFS server to indicate that it /doesn't/ implement an attribute, but then also indicate that clients /are/ allowed to set that attribute using OPEN(create) with EXCLUSIVE4_1. Ensure that the SECURITY_LABEL and ACL bits are not set in the suppattr_exclcreat bitmask when they are also not set in the supported_attrs bitmask. Fixes: 8c18f2052e75 ("nfsd41: SUPPATTR_EXCLCREAT attribute") Cc: stable@vger.kernel.org Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfs4xdr.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index e6b000a4a31aa..fd81db17691a1 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -3362,6 +3362,11 @@ static __be32 nfsd4_encode_fattr4_suppattr_exclcreat(struct xdr_stream *xdr, u32 supp[3]; memcpy(supp, nfsd_suppattrs[resp->cstate.minorversion], sizeof(supp)); + if (!IS_POSIXACL(d_inode(args->dentry))) + supp[0] &= ~FATTR4_WORD0_ACL; + if (!args->contextsupport) + supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL; + supp[0] &= NFSD_SUPPATTR_EXCLCREAT_WORD0; supp[1] &= NFSD_SUPPATTR_EXCLCREAT_WORD1; supp[2] &= NFSD_SUPPATTR_EXCLCREAT_WORD2; -- 2.47.3