From 68eb35081e297b37db49d854cda144c6a3397699 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Tue, 21 Aug 2012 12:48:30 -0400 Subject: nfsd4: don't pin clientids to pseudoflavors I added cr_flavor to the data compared in same_creds without any justification, in d5497fc693a446ce9100fcf4117c3f795ddfd0d2 "nfsd4: move rq_flavor into svc_cred". Recent client changes then started making mount -osec=krb5 server:/export /mnt/ echo "hello" >/mnt/TMP umount /mnt/ mount -osec=krb5i server:/export /mnt/ echo "hello" >/mnt/TMP to fail due to a clid_inuse on the second open. Mounting sequentially like this with different flavors probably isn't that common outside artificial tests. Also, the real bug here may be that the server isn't just destroying the former clientid in this case (because it isn't good enough at recognizing when the old state is gone). But it prompted some discussion and a look back at the spec, and I think the check was probably wrong. Fix and document. Cc: stable@kernel.org Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 5122e17..0f8d7e7 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1223,10 +1223,26 @@ static bool groups_equal(struct group_info *g1, struct group_info *g2) return true; } +/* + * RFC 3530 language requires clid_inuse be returned when the + * "principal" associated with a requests differs from that previously + * used. We use uid, gid's, and gss principal string as our best + * approximation. We also don't want to allow non-gss use of a client + * established using gss: in theory cr_principal should catch that + * change, but in practice cr_principal can be null even in the gss case + * since gssd doesn't always pass down a principal string. + */ +static bool is_gss_cred(struct svc_cred *cr) +{ + /* Is cr_flavor one of the gss "pseudoflavors"?: */ + return (cr->cr_flavor > RPC_AUTH_MAXFLAVOR); +} + + static bool same_creds(struct svc_cred *cr1, struct svc_cred *cr2) { - if ((cr1->cr_flavor != cr2->cr_flavor) + if ((is_gss_cred(cr1) != is_gss_cred(cr2)) || (cr1->cr_uid != cr2->cr_uid) || (cr1->cr_gid != cr2->cr_gid) || !groups_equal(cr1->cr_group_info, cr2->cr_group_info)) -- cgit v1.1