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[src/trunk]: src/sys/nfs Use a random opaque cookie, not kva pointer, for nfs...
details: https://anonhg.NetBSD.org/src/rev/69f215712b7c
branches: trunk
changeset: 359014:69f215712b7c
user: riastradh <riastradh%NetBSD.org@localhost>
date: Thu Jan 25 17:14:36 2018 +0000
description:
Use a random opaque cookie, not kva pointer, for nfssvc(2).
(What were they smoking?!)
I suspect most of this is actually dead code that wasn't properly
amputated along with the rest of the gangrene of NFSKERB a decade
ago, but I'm out of time to investigate further. If someone else
wants to kill NFSSVC_AUTHIN/NFSSVC_AUTHINFAIL and the rest of the
tentacular kerberosity, be my guest.
Noted by Silvio Cesare of InfoSect.
diffstat:
sys/nfs/nfs.h | 7 +-
sys/nfs/nfs_syscalls.c | 151 ++++++++++++++++++++++++++++++++++++++++++++----
2 files changed, 141 insertions(+), 17 deletions(-)
diffs (truncated from 309 to 300 lines):
diff -r 9dfb33e7fd63 -r 69f215712b7c sys/nfs/nfs.h
--- a/sys/nfs/nfs.h Thu Jan 25 16:05:11 2018 +0000
+++ b/sys/nfs/nfs.h Thu Jan 25 17:14:36 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: nfs.h,v 1.76 2018/01/21 20:36:49 christos Exp $ */
+/* $NetBSD: nfs.h,v 1.77 2018/01/25 17:14:36 riastradh Exp $ */
/*
* Copyright (c) 1989, 1993, 1995
* The Regents of the University of California. All rights reserved.
@@ -41,6 +41,7 @@
#include <sys/fstypes.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
+#include <sys/rbtree.h>
#endif
/*
@@ -486,7 +487,7 @@
* One of these structures is allocated for each nfsd.
*/
struct nfsd {
- TAILQ_ENTRY(nfsd) nfsd_chain; /* List of all nfsd's */
+ struct rb_node nfsd_node; /* Tree of all nfsd's */
SLIST_ENTRY(nfsd) nfsd_idle; /* List of idle nfsd's */
kcondvar_t nfsd_cv;
int nfsd_flag; /* NFSD_ flags */
@@ -497,6 +498,7 @@
u_char nfsd_verfstr[RPCVERF_MAXSIZ];
struct proc *nfsd_procp; /* Proc ptr */
struct nfsrv_descript *nfsd_nd; /* Associated nfsrv_descript */
+ uint32_t nfsd_cookie; /* Userland cookie, fits 32bit ptr */
};
/* Bits for "nfsd_flag" */
@@ -557,7 +559,6 @@
extern kmutex_t nfsd_lock;
extern kcondvar_t nfsd_initcv;
-extern TAILQ_HEAD(nfsdhead, nfsd) nfsd_head;
extern SLIST_HEAD(nfsdidlehead, nfsd) nfsd_idle_head;
extern int nfsd_head_flag;
#define NFSD_CHECKSLP 0x01
diff -r 9dfb33e7fd63 -r 69f215712b7c sys/nfs/nfs_syscalls.c
--- a/sys/nfs/nfs_syscalls.c Thu Jan 25 16:05:11 2018 +0000
+++ b/sys/nfs/nfs_syscalls.c Thu Jan 25 17:14:36 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: nfs_syscalls.c,v 1.158 2017/02/12 18:24:31 maxv Exp $ */
+/* $NetBSD: nfs_syscalls.c,v 1.159 2018/01/25 17:14:36 riastradh Exp $ */
/*
* Copyright (c) 1989, 1993
@@ -35,7 +35,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nfs_syscalls.c,v 1.158 2017/02/12 18:24:31 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nfs_syscalls.c,v 1.159 2018/01/25 17:14:36 riastradh Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -61,6 +61,8 @@
#include <sys/kthread.h>
#include <sys/kauth.h>
#include <sys/syscallargs.h>
+#include <sys/cprng.h>
+#include <sys/rbtree.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
@@ -87,9 +89,11 @@
struct nfssvc_sockhead nfssvc_sockhead;
kcondvar_t nfsd_initcv;
struct nfssvc_sockhead nfssvc_sockpending;
-struct nfsdhead nfsd_head;
struct nfsdidlehead nfsd_idle_head;
+static rb_tree_t nfsd_tree;
+static const rb_tree_ops_t nfsd_tree_ops;
+
int nfssvc_sockhead_flag;
int nfsd_head_flag;
@@ -102,12 +106,118 @@
static int nfssvc_nfsd(struct nfssvc_copy_ops *, struct nfsd_srvargs *, void *,
struct lwp *);
+static int nfsd_compare_nodes(void *, const void *, const void *);
+static int nfsd_compare_key(void *, const void *, const void *);
+
+static struct nfsd *nfsd_bake_cookie(struct nfsd *);
+static void nfsd_toss_cookie(struct nfsd *);
+static struct nfsd *nfsd_get(struct nfsd *);
+
static int nfssvc_addsock_in(struct nfsd_args *, const void *);
static int nfssvc_setexports_in(struct mountd_exports_list *, const void *);
static int nfssvc_nsd_in(struct nfsd_srvargs *, const void *);
static int nfssvc_nsd_out(void *, const struct nfsd_srvargs *);
static int nfssvc_exp_in(struct export_args *, const void *, size_t);
+static const rb_tree_ops_t nfsd_tree_ops = {
+ .rbto_compare_nodes = nfsd_compare_nodes,
+ .rbto_compare_key = nfsd_compare_key,
+ .rbto_node_offset = offsetof(struct nfsd, nfsd_node),
+};
+
+static int
+nfsd_compare_nodes(void *cookie, const void *va, const void *vb)
+{
+ const struct nfsd *na = va;
+ const struct nfsd *nb = vb;
+
+ if (na->nfsd_cookie < nb->nfsd_cookie)
+ return -1;
+ if (na->nfsd_cookie > nb->nfsd_cookie)
+ return +1;
+ return 0;
+}
+
+static int
+nfsd_compare_key(void *cookie, const void *vn, const void *vk)
+{
+ const struct nfsd *n = vn;
+ const uint32_t *k = vk;
+
+ if (n->nfsd_cookie < *k)
+ return -1;
+ if (n->nfsd_cookie > *k)
+ return +1;
+ return 0;
+}
+
+/*
+ * nfsd_bake_cookie(nfsd)
+ *
+ * Bake a cookie for nfsd, hang it on the tree of nfsds, and
+ * return a userland-safe pointer nfsdu neatly packed for
+ * transport in struct nfsd_srvargs::nsd_nfsd.
+ */
+static struct nfsd *
+nfsd_bake_cookie(struct nfsd *nfsd)
+{
+
+ KASSERT(mutex_owned(&nfsd_lock));
+
+ do {
+ nfsd->nfsd_cookie = cprng_fast32();
+ } while (nfsd->nfsd_cookie == 0 ||
+ rb_tree_insert_node(&nfsd_tree, nfsd) != nfsd);
+
+ return (struct nfsd *)(uintptr_t)nfsd->nfsd_cookie;
+}
+
+/*
+ * nfsd_toss_cookie(nfsd)
+ *
+ * Toss nfsd's cookie.
+ */
+static void
+nfsd_toss_cookie(struct nfsd *nfsd)
+{
+
+ KASSERT(mutex_owned(&nfsd_lock));
+ KASSERT(nfsd->nfsd_cookie != 0);
+
+ rb_tree_remove_node(&nfsd_tree, nfsd);
+ nfsd->nfsd_cookie = 0; /* paranoia */
+}
+
+/*
+ * nfsd_get(nfsdu)
+ *
+ * Return the struct nfsd pointer for the userland nfsdu cookie,
+ * as stored in struct nfsd_srvargs::nsd_nfsd, or NULL if nfsdu is
+ * not a current valid nfsd cookie.
+ *
+ * Caller MUST NOT hold nfsd_lock. Caller MUST NOT pass (struct
+ * nfsd *)(uintptr_t)0, which is the sentinel value for no nfsd
+ * cookie, for which the caller should check first.
+ */
+static struct nfsd *
+nfsd_get(struct nfsd *nfsdu)
+{
+ uintptr_t cookie = (uintptr_t)nfsdu;
+ uint32_t key;
+ struct nfsd *nfsd;
+
+ KASSERT(cookie != 0);
+ if (cookie > UINT32_MAX)
+ return NULL;
+ key = cookie;
+
+ mutex_enter(&nfsd_lock);
+ nfsd = rb_tree_find_node(&nfsd_tree, &key);
+ mutex_exit(&nfsd_lock);
+
+ return nfsd;
+}
+
static int
nfssvc_addsock_in(struct nfsd_args *nfsdarg, const void *argp)
{
@@ -184,7 +294,7 @@
struct mbuf *nam;
struct nfsd_args nfsdarg;
struct nfsd_srvargs nfsd_srvargs, *nsd = &nfsd_srvargs;
- struct nfsd *nfsd;
+ struct nfsd *nfsd = NULL;
struct nfssvc_sock *slp;
struct nfsuid *nuidp;
@@ -254,8 +364,11 @@
error = ops->nsd_in(nsd, argp);
if (error)
return (error);
+ if ((uintptr_t)nsd->nsd_nfsd != 0 &&
+ (nfsd = nfsd_get(nsd->nsd_nfsd)) == NULL)
+ return (EINVAL);
if ((flag & NFSSVC_AUTHIN) &&
- ((nfsd = nsd->nsd_nfsd)) != NULL &&
+ nfsd != NULL &&
(nfsd->nfsd_slp->ns_flags & SLP_VALID)) {
slp = nfsd->nfsd_slp;
@@ -340,7 +453,7 @@
}
}
if ((flag & NFSSVC_AUTHINFAIL) &&
- (nfsd = nsd->nsd_nfsd))
+ nfsd != NULL)
nfsd->nfsd_flag |= NFSD_AUTHFAIL;
error = nfssvc_nfsd(ops, nsd, argp, l);
}
@@ -481,7 +594,7 @@
struct timeval tv;
struct mbuf *m;
struct nfssvc_sock *slp;
- struct nfsd *nfsd = nsd->nsd_nfsd;
+ struct nfsd *nfsd;
struct nfsrv_descript *nd = NULL;
struct mbuf *mreq;
u_quad_t cur_usec;
@@ -493,8 +606,12 @@
cacherep = RC_DOIT;
writes_todo = 0;
#endif
- if (nfsd == NULL) {
- nsd->nsd_nfsd = nfsd = kmem_alloc(sizeof(*nfsd), KM_SLEEP);
+ /*
+ * If userland didn't provide an nfsd cookie, bake a fresh one;
+ * if they did provide one, look it up.
+ */
+ if ((uintptr_t)nsd->nsd_nfsd == 0) {
+ nfsd = kmem_alloc(sizeof(*nfsd), KM_SLEEP);
memset(nfsd, 0, sizeof (struct nfsd));
cv_init(&nfsd->nfsd_cv, "nfsd");
nfsd->nfsd_procp = p;
@@ -503,10 +620,15 @@
KASSERT(nfs_numnfsd == 0);
cv_wait(&nfsd_initcv, &nfsd_lock);
}
- TAILQ_INSERT_TAIL(&nfsd_head, nfsd, nfsd_chain);
+ nsd->nsd_nfsd = nfsd_bake_cookie(nfsd);
nfs_numnfsd++;
mutex_exit(&nfsd_lock);
+ } else if ((nfsd = nfsd_get(nsd->nsd_nfsd)) == NULL) {
+ return (EINVAL);
}
+ KASSERT(nfsd != NULL);
+ KASSERT(nsd->nsd_nfsd != (struct nfsd *)(uintptr_t)0);
+
/*
* Loop getting rpc requests until SIGKILL.
*/
@@ -759,14 +881,15 @@
}
done:
mutex_enter(&nfsd_lock);
- TAILQ_REMOVE(&nfsd_head, nfsd, nfsd_chain);
+ nfsd_toss_cookie(nfsd);
doreinit = --nfs_numnfsd == 0;
if (doreinit)
nfssvc_sockhead_flag |= SLP_INIT;
mutex_exit(&nfsd_lock);
cv_destroy(&nfsd->nfsd_cv);
kmem_free(nfsd, sizeof(*nfsd));
- nsd->nsd_nfsd = NULL;
+ KASSERT(nsd->nsd_nfsd != (struct nfsd *)(uintptr_t)0);
+ nsd->nsd_nfsd = (struct nfsd *)(uintptr_t)0;
if (doreinit)
nfsrv_init(true); /* Reinitialize everything */
return (error);
@@ -895,7 +1018,7 @@
if (terminating) {
KASSERT(SLIST_EMPTY(&nfsd_idle_head));
- KASSERT(TAILQ_EMPTY(&nfsd_head));
+ KASSERT(RB_TREE_MIN(&nfsd_tree) == NULL);
while ((slp = TAILQ_FIRST(&nfssvc_sockhead)) != NULL) {
mutex_exit(&nfsd_lock);
KASSERT(slp->ns_sref == 0);
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