From 0a183f24a7ae48b7c0f2327989754b5db5de02b8 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 5 Sep 2024 15:09:38 -0400 Subject: [PATCH] NFSD: Handle @rqstp == NULL in check_nfsd_access() LOCALIO-initiated open operations are not running in an nfsd thread and thus do not have an associated svc_rqst context. Signed-off-by: NeilBrown Co-developed-by: Mike Snitzer Signed-off-by: Mike Snitzer Signed-off-by: Chuck Lever Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker --- fs/nfsd/export.c | 30 +++++++++++++++++++++++++----- 1 file changed, 25 insertions(+), 5 deletions(-) diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c index 7bb4f2075ac5..c82d8e3e0d4f 100644 --- a/fs/nfsd/export.c +++ b/fs/nfsd/export.c @@ -1074,10 +1074,30 @@ static struct svc_export *exp_find(struct cache_detail *cd, return exp; } +/** + * check_nfsd_access - check if access to export is allowed. + * @exp: svc_export that is being accessed. + * @rqstp: svc_rqst attempting to access @exp (will be NULL for LOCALIO). + * + * Return values: + * %nfs_ok if access is granted, or + * %nfserr_wrongsec if access is denied + */ __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp) { struct exp_flavor_info *f, *end = exp->ex_flavors + exp->ex_nflavors; - struct svc_xprt *xprt = rqstp->rq_xprt; + struct svc_xprt *xprt; + + /* + * If rqstp is NULL, this is a LOCALIO request which will only + * ever use a filehandle/credential pair for which access has + * been affirmed (by ACCESS or OPEN NFS requests) over the + * wire. So there is no need for further checks here. + */ + if (!rqstp) + return nfs_ok; + + xprt = rqstp->rq_xprt; if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_NONE) { if (!test_bit(XPT_TLS_SESSION, &xprt->xpt_flags)) @@ -1098,17 +1118,17 @@ __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp) ok: /* legacy gss-only clients are always OK: */ if (exp->ex_client == rqstp->rq_gssclient) - return 0; + return nfs_ok; /* ip-address based client; check sec= export option: */ for (f = exp->ex_flavors; f < end; f++) { if (f->pseudoflavor == rqstp->rq_cred.cr_flavor) - return 0; + return nfs_ok; } /* defaults in absence of sec= options: */ if (exp->ex_nflavors == 0) { if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL || rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX) - return 0; + return nfs_ok; } /* If the compound op contains a spo_must_allowed op, @@ -1118,7 +1138,7 @@ ok: */ if (nfsd4_spo_must_allow(rqstp)) - return 0; + return nfs_ok; denied: return nfserr_wrongsec;