MFC r305209: MFV r302660: 6314 buffer overflow in dsl_dataset_name

illumos/illumos-gate@9adfa60d484ce2435f5af77cc99dcd4e692b6660
https://github.com/illumos/illumos-gate/commit/9adfa60d484ce2435f5af77cc99dcd4e6
92b6660

https://www.illumos.org/issues/6314
  Callers of dsl_dataset_name pass a buffer of size ZFS_MAXNAMELEN, but
  dsl_dataset_name copies the datasets' name PLUS the snapshot name to it,
  resulting in a max of 2 * ZFS_MAXNAMELEN + '@'.

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Igor Kozhukhov <ikozhukhov@gmail.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Author: Matthew Ahrens <mahrens@delphix.com>

10 files changed, 65 insertions, 64 deletions

diff --git a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs.h b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs.h
index 6c133be..c84124e 100644
--- a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs.h
+++ b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs.h
@@ -51,8 +51,6 @@ extern "C" {
 /*
  * Miscellaneous ZFS constants
  */
-#define	ZFS_MAXNAMELEN		MAXNAMELEN
-#define	ZPOOL_MAXNAMELEN	MAXNAMELEN
 #define	ZFS_MAXPROPLEN		MAXPATHLEN
 #define	ZPOOL_MAXPROPLEN	MAXPATHLEN
 
diff --git a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_changelist.c b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_changelist.c
index c078bf2..277e99e 100644
--- a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_changelist.c
+++ b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_changelist.c
@@ -26,6 +26,7 @@
  * Portions Copyright 2007 Ramprakash Jelari
  * Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>.
  * All rights reserved.
+ * Copyright (c) 2014, 2015 by Delphix. All rights reserved.
  * Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com>
  */
 
@@ -296,7 +297,7 @@ void
 changelist_rename(prop_changelist_t *clp, const char *src, const char *dst)
 {
 	prop_changenode_t *cn;
-	char newname[ZFS_MAXNAMELEN];
+	char newname[ZFS_MAX_DATASET_NAME_LEN];
 
 	for (cn = uu_list_first(clp->cl_list); cn != NULL;
 	    cn = uu_list_next(clp->cl_list, cn)) {
diff --git a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c
index a31bc5e..8e69f3c 100644
--- a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c
+++ b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c
@@ -554,7 +554,7 @@ zfs_bookmark_exists(const char *path)
 {
 	nvlist_t *bmarks;
 	nvlist_t *props;
-	char fsname[ZFS_MAXNAMELEN];
+	char fsname[ZFS_MAX_DATASET_NAME_LEN];
 	char *bmark_name;
 	char *pound;
 	int err;
@@ -2181,7 +2181,7 @@ struct get_clones_arg {
 	uint64_t numclones;
 	nvlist_t *value;
 	const char *origin;
-	char buf[ZFS_MAXNAMELEN];
+	char buf[ZFS_MAX_DATASET_NAME_LEN];
 };
 
 int
@@ -2236,7 +2236,7 @@ zfs_get_clones_nvl(zfs_handle_t *zhp)
 
 		if (gca.numclones != 0) {
 			zfs_handle_t *root;
-			char pool[ZFS_MAXNAMELEN];
+			char pool[ZFS_MAX_DATASET_NAME_LEN];
 			char *cp = pool;
 
 			/* get the pool name */
@@ -3021,7 +3021,7 @@ check_parents(libzfs_handle_t *hdl, const char *path, uint64_t *zoned,
     boolean_t accept_ancestor, int *prefixlen)
 {
 	zfs_cmd_t zc = { 0 };
-	char parent[ZFS_MAXNAMELEN];
+	char parent[ZFS_MAX_DATASET_NAME_LEN];
 	char *slash;
 	zfs_handle_t *zhp;
 	char errbuf[1024];
@@ -3260,7 +3260,7 @@ zfs_create(libzfs_handle_t *hdl, const char *path, zfs_type_t type,
 		ost = LZC_DATSET_TYPE_ZFS;
 
 	/* open zpool handle for prop validation */
-	char pool_path[MAXNAMELEN];
+	char pool_path[ZFS_MAX_DATASET_NAME_LEN];
 	(void) strlcpy(pool_path, path, sizeof (pool_path));
 
 	/* truncate pool_path at first slash */
@@ -3329,7 +3329,7 @@ zfs_create(libzfs_handle_t *hdl, const char *path, zfs_type_t type,
 
 	/* check for failure */
 	if (ret != 0) {
-		char parent[ZFS_MAXNAMELEN];
+		char parent[ZFS_MAX_DATASET_NAME_LEN];
 		(void) parent_name(path, parent, sizeof (parent));
 
 		switch (errno) {
@@ -3419,7 +3419,7 @@ static int
 zfs_check_snap_cb(zfs_handle_t *zhp, void *arg)
 {
 	struct destroydata *dd = arg;
-	char name[ZFS_MAXNAMELEN];
+	char name[ZFS_MAX_DATASET_NAME_LEN];
 	int rv = 0;
 
 	(void) snprintf(name, sizeof (name),
@@ -3509,7 +3509,7 @@ zfs_destroy_snaps_nvl(libzfs_handle_t *hdl, nvlist_t *snaps, boolean_t defer)
 int
 zfs_clone(zfs_handle_t *zhp, const char *target, nvlist_t *props)
 {
-	char parent[ZFS_MAXNAMELEN];
+	char parent[ZFS_MAX_DATASET_NAME_LEN];
 	int ret;
 	char errbuf[1024];
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
@@ -3639,7 +3639,7 @@ static int
 zfs_snapshot_cb(zfs_handle_t *zhp, void *arg)
 {
 	snapdata_t *sd = arg;
-	char name[ZFS_MAXNAMELEN];
+	char name[ZFS_MAX_DATASET_NAME_LEN];
 	int rv = 0;
 
 	if (zfs_prop_get_int(zhp, ZFS_PROP_INCONSISTENT) == 0) {
@@ -3688,7 +3688,7 @@ zfs_snapshot_nvl(libzfs_handle_t *hdl, nvlist_t *snaps, nvlist_t *props)
 	 * get pool handle for prop validation. assumes all snaps are in the
 	 * same pool, as does lzc_snapshot (below).
 	 */
-	char pool[MAXNAMELEN];
+	char pool[ZFS_MAX_DATASET_NAME_LEN];
 	elem = nvlist_next_nvpair(snaps, NULL);
 	(void) strlcpy(pool, nvpair_name(elem), sizeof (pool));
 	pool[strcspn(pool, "/@")] = '\0';
@@ -3742,7 +3742,7 @@ zfs_snapshot(libzfs_handle_t *hdl, const char *path, boolean_t recursive,
 {
 	int ret;
 	snapdata_t sd = { 0 };
-	char fsname[ZFS_MAXNAMELEN];
+	char fsname[ZFS_MAX_DATASET_NAME_LEN];
 	char *cp;
 	zfs_handle_t *zhp;
 	char errbuf[1024];
@@ -3921,7 +3921,7 @@ zfs_rename(zfs_handle_t *zhp, const char *source, const char *target,
 	prop_changelist_t *cl = NULL;
 	zfs_handle_t *zhrp = NULL;
 	char *parentname = NULL;
-	char parent[ZFS_MAXNAMELEN];
+	char parent[ZFS_MAX_DATASET_NAME_LEN];
 	char property[ZFS_MAXPROPLEN];
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
 	char errbuf[1024];
@@ -4435,7 +4435,7 @@ static int
 zfs_hold_one(zfs_handle_t *zhp, void *arg)
 {
 	struct holdarg *ha = arg;
-	char name[ZFS_MAXNAMELEN];
+	char name[ZFS_MAX_DATASET_NAME_LEN];
 	int rv = 0;
 
 	(void) snprintf(name, sizeof (name),
@@ -4554,7 +4554,7 @@ static int
 zfs_release_one(zfs_handle_t *zhp, void *arg)
 {
 	struct holdarg *ha = arg;
-	char name[ZFS_MAXNAMELEN];
+	char name[ZFS_MAX_DATASET_NAME_LEN];
 	int rv = 0;
 	nvlist_t *existing_holds;
 
@@ -4683,7 +4683,7 @@ tryagain:
 	zc.zc_nvlist_dst_size = nvsz;
 	zc.zc_nvlist_dst = (uintptr_t)nvbuf;
 
-	(void) strlcpy(zc.zc_name, zhp->zfs_name, ZFS_MAXNAMELEN);
+	(void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
 
 	if (ioctl(hdl->libzfs_fd, ZFS_IOC_GET_FSACL, &zc) != 0) {
 		(void) snprintf(errbuf, sizeof (errbuf),
diff --git a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_diff.c b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_diff.c
index e90f464..1447b4c 100644
--- a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_diff.c
+++ b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_diff.c
@@ -22,6 +22,7 @@
 /*
  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2015 Nexenta Systems, Inc. All rights reserved.
+ * Copyright (c) 2015 by Delphix. All rights reserved.
  * Copyright 2016 Joyent, Inc.
  * Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com>
  */
@@ -618,7 +619,7 @@ get_snapshot_names(differ_info_t *di, const char *fromsnap,
 		 * not the same dataset name, might be okay if
 		 * tosnap is a clone of a fromsnap descendant.
 		 */
-		char origin[ZFS_MAXNAMELEN];
+		char origin[ZFS_MAX_DATASET_NAME_LEN];
 		zprop_source_t src;
 		zfs_handle_t *zhp;
 
diff --git a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_impl.h b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_impl.h
index e67bf40..bd051ae 100644
--- a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_impl.h
+++ b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_impl.h
@@ -22,18 +22,18 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2011 Pawel Jakub Dawidek. All rights reserved.
- * Copyright (c) 2013 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2015 by Delphix. All rights reserved.
  * Copyright (c) 2013 Martin Matuska <mm@FreeBSD.org>. All rights reserved.
  */
 
 #ifndef	_LIBZFS_IMPL_H
 #define	_LIBZFS_IMPL_H
 
-#include <sys/dmu.h>
 #include <sys/fs/zfs.h>
-#include <sys/zfs_ioctl.h>
 #include <sys/spa.h>
 #include <sys/nvpair.h>
+#include <sys/dmu.h>
+#include <sys/zfs_ioctl.h>
 
 #include <libshare.h>
 #include <libuutil.h>
@@ -86,7 +86,7 @@ struct libzfs_handle {
 struct zfs_handle {
 	libzfs_handle_t *zfs_hdl;
 	zpool_handle_t *zpool_hdl;
-	char zfs_name[ZFS_MAXNAMELEN];
+	char zfs_name[ZFS_MAX_DATASET_NAME_LEN];
 	zfs_type_t zfs_type; /* type including snapshot */
 	zfs_type_t zfs_head_type; /* type excluding snapshot */
 	dmu_objset_stats_t zfs_dmustats;
@@ -107,7 +107,7 @@ struct zfs_handle {
 struct zpool_handle {
 	libzfs_handle_t *zpool_hdl;
 	zpool_handle_t *zpool_next;
-	char zpool_name[ZPOOL_MAXNAMELEN];
+	char zpool_name[ZFS_MAX_DATASET_NAME_LEN];
 	int zpool_state;
 	size_t zpool_config_size;
 	nvlist_t *zpool_config;
diff --git a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_iter.c b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_iter.c
index e56c418..ac26a67 100644
--- a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_iter.c
+++ b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_iter.c
@@ -197,7 +197,7 @@ zfs_iter_bookmarks(zfs_handle_t *zhp, zfs_iter_f func, void *data)
 
 	for (nvpair_t *pair = nvlist_next_nvpair(bmarks, NULL);
 	    pair != NULL; pair = nvlist_next_nvpair(bmarks, pair)) {
-		char name[ZFS_MAXNAMELEN];
+		char name[ZFS_MAX_DATASET_NAME_LEN];
 		char *bmark_name;
 		nvlist_t *bmark_props;
 
@@ -385,7 +385,7 @@ zfs_iter_snapspec(zfs_handle_t *fs_zhp, const char *spec_orig,
 			 * exists.
 			 */
 			if (ssa.ssa_last[0] != '\0') {
-				char snapname[ZFS_MAXNAMELEN];
+				char snapname[ZFS_MAX_DATASET_NAME_LEN];
 				(void) snprintf(snapname, sizeof (snapname),
 				    "%s@%s", zfs_get_name(fs_zhp),
 				    ssa.ssa_last);
@@ -405,7 +405,7 @@ zfs_iter_snapspec(zfs_handle_t *fs_zhp, const char *spec_orig,
 				ret = ENOENT;
 			}
 		} else {
-			char snapname[ZFS_MAXNAMELEN];
+			char snapname[ZFS_MAX_DATASET_NAME_LEN];
 			zfs_handle_t *snap_zhp;
 			(void) snprintf(snapname, sizeof (snapname), "%s@%s",
 			    zfs_get_name(fs_zhp), comma_separated);
diff --git a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c
index cba6d56..60c6266 100644
--- a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c
+++ b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c
@@ -236,7 +236,7 @@ static boolean_t
 zfs_is_mountable(zfs_handle_t *zhp, char *buf, size_t buflen,
     zprop_source_t *source)
 {
-	char sourceloc[ZFS_MAXNAMELEN];
+	char sourceloc[MAXNAMELEN];
 	zprop_source_t sourcetype;
 
 	if (!zfs_prop_valid_for_type(ZFS_PROP_MOUNTPOINT, zhp->zfs_type))
diff --git a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_pool.c b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_pool.c
index 4190572..035f028 100644
--- a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_pool.c
+++ b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_pool.c
@@ -407,7 +407,7 @@ bootfs_name_valid(const char *pool, char *bootfs)
 boolean_t
 zpool_is_bootable(zpool_handle_t *zhp)
 {
-	char bootfs[ZPOOL_MAXNAMELEN];
+	char bootfs[ZFS_MAX_DATASET_NAME_LEN];
 
 	return (zpool_get_prop(zhp, ZPOOL_PROP_BOOTFS, bootfs,
 	    sizeof (bootfs), NULL, B_FALSE) == 0 && strncmp(bootfs, "-",
@@ -3803,7 +3803,7 @@ zpool_obj_to_path(zpool_handle_t *zhp, uint64_t dsobj, uint64_t obj,
 	zfs_cmd_t zc = { 0 };
 	boolean_t mounted = B_FALSE;
 	char *mntpnt = NULL;
-	char dsname[MAXNAMELEN];
+	char dsname[ZFS_MAX_DATASET_NAME_LEN];
 
 	if (dsobj == 0) {
 		/* special case for the MOS */
@@ -4064,7 +4064,7 @@ zvol_check_dump_config(char *arg)
 	uint_t toplevels;
 	libzfs_handle_t *hdl;
 	char errbuf[1024];
-	char poolname[ZPOOL_MAXNAMELEN];
+	char poolname[ZFS_MAX_DATASET_NAME_LEN];
 	int pathlen = strlen(ZVOL_FULL_DEV_DIR);
 	int ret = 1;
 
@@ -4087,7 +4087,7 @@ zvol_check_dump_config(char *arg)
 		    "malformed dataset name"));
 		(void) zfs_error(hdl, EZFS_INVALIDNAME, errbuf);
 		return (1);
-	} else if (p - volname >= ZFS_MAXNAMELEN) {
+	} else if (p - volname >= ZFS_MAX_DATASET_NAME_LEN) {
 		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
 		    "dataset name is too long"));
 		(void) zfs_error(hdl, EZFS_NAMETOOLONG, errbuf);
diff --git a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_sendrecv.c b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_sendrecv.c
index bc8c788..3b315b7 100644
--- a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_sendrecv.c
+++ b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_sendrecv.c
@@ -752,7 +752,7 @@ send_iterate_prop(zfs_handle_t *zhp, nvlist_t *nv)
 static uint64_t
 get_snap_txg(libzfs_handle_t *hdl, const char *fs, const char *snap)
 {
-	char name[ZFS_MAXNAMELEN];
+	char name[ZFS_MAX_DATASET_NAME_LEN];
 	uint64_t txg = 0;
 
 	if (fs == NULL || fs[0] == '\0' || snap == NULL || snap[0] == '\0')
@@ -920,7 +920,7 @@ typedef struct send_dump_data {
 	/* these are all just the short snapname (the part after the @) */
 	const char *fromsnap;
 	const char *tosnap;
-	char prevsnap[ZFS_MAXNAMELEN];
+	char prevsnap[ZFS_MAX_DATASET_NAME_LEN];
 	uint64_t prevsnap_obj;
 	boolean_t seenfrom, seento, replicate, doall, fromorigin;
 	boolean_t verbose, dryrun, parsable, progress, embed_data, std_out;
@@ -933,7 +933,7 @@ typedef struct send_dump_data {
 	snapfilter_cb_t *filter_cb;
 	void *filter_cb_arg;
 	nvlist_t *debugnv;
-	char holdtag[ZFS_MAXNAMELEN];
+	char holdtag[ZFS_MAX_DATASET_NAME_LEN];
 	int cleanup_fd;
 	uint64_t size;
 } send_dump_data_t;
@@ -1569,7 +1569,7 @@ zfs_send_resume(libzfs_handle_t *hdl, sendflags_t *flags, int outfd,
 	uint64_t resumeobj, resumeoff, toguid, fromguid, bytes;
 	zfs_handle_t *zhp;
 	int error = 0;
-	char name[ZFS_MAXNAMELEN];
+	char name[ZFS_MAX_DATASET_NAME_LEN];
 	enum lzc_send_flags lzc_flags = 0;
 
 	(void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
@@ -2163,8 +2163,8 @@ recv_rename(libzfs_handle_t *hdl, const char *name, const char *tryname,
 	if (err != 0 && strncmp(name + baselen, "recv-", 5) != 0) {
 		seq++;
 
-		(void) snprintf(newname, ZFS_MAXNAMELEN, "%.*srecv-%u-%u",
-		    baselen, name, getpid(), seq);
+		(void) snprintf(newname, ZFS_MAX_DATASET_NAME_LEN,
+		    "%.*srecv-%u-%u", baselen, name, getpid(), seq);
 		(void) strlcpy(zc.zc_value, newname, sizeof (zc.zc_value));
 
 		if (flags->verbose) {
@@ -2292,7 +2292,7 @@ static int
 guid_to_name(libzfs_handle_t *hdl, const char *parent, uint64_t guid,
     boolean_t bookmark_ok, char *name)
 {
-	char pname[ZFS_MAXNAMELEN];
+	char pname[ZFS_MAX_DATASET_NAME_LEN];
 	guid_to_name_data_t gtnd;
 
 	gtnd.guid = guid;
@@ -2347,7 +2347,7 @@ created_before(libzfs_handle_t *hdl, avl_tree_t *avl,
 {
 	nvlist_t *nvfs;
 	char *fsname, *snapname;
-	char buf[ZFS_MAXNAMELEN];
+	char buf[ZFS_MAX_DATASET_NAME_LEN];
 	int rv;
 	zfs_handle_t *guid1hdl, *guid2hdl;
 	uint64_t create1, create2;
@@ -2398,7 +2398,7 @@ recv_incremental_replication(libzfs_handle_t *hdl, const char *tofs,
 	avl_tree_t *local_avl;
 	nvpair_t *fselem, *nextfselem;
 	char *fromsnap;
-	char newname[ZFS_MAXNAMELEN];
+	char newname[ZFS_MAX_DATASET_NAME_LEN];
 	char guidname[32];
 	int error;
 	boolean_t needagain, progress, recursive;
@@ -2517,7 +2517,7 @@ again:
 
 			/* check for delete */
 			if (found == NULL) {
-				char name[ZFS_MAXNAMELEN];
+				char name[ZFS_MAX_DATASET_NAME_LEN];
 
 				if (!flags->force)
 					continue;
@@ -2557,8 +2557,8 @@ again:
 			/* check for different snapname */
 			if (strcmp(nvpair_name(snapelem),
 			    stream_snapname) != 0) {
-				char name[ZFS_MAXNAMELEN];
-				char tryname[ZFS_MAXNAMELEN];
+				char name[ZFS_MAX_DATASET_NAME_LEN];
+				char tryname[ZFS_MAX_DATASET_NAME_LEN];
 
 				(void) snprintf(name, sizeof (name), "%s@%s",
 				    fsname, nvpair_name(snapelem));
@@ -2640,7 +2640,7 @@ again:
 		    ((flags->isprefix || strcmp(tofs, fsname) != 0) &&
 		    (s1 != NULL) && (s2 != NULL) && strcmp(s1, s2) != 0)) {
 			nvlist_t *parent;
-			char tryname[ZFS_MAXNAMELEN];
+			char tryname[ZFS_MAX_DATASET_NAME_LEN];
 
 			parent = fsavl_find(local_avl,
 			    stream_parent_fromsnap_guid, NULL);
@@ -2708,8 +2708,8 @@ zfs_receive_package(libzfs_handle_t *hdl, int fd, const char *destname,
 	char *fromsnap = NULL;
 	char *sendsnap = NULL;
 	char *cp;
-	char tofs[ZFS_MAXNAMELEN];
-	char sendfs[ZFS_MAXNAMELEN];
+	char tofs[ZFS_MAX_DATASET_NAME_LEN];
+	char sendfs[ZFS_MAX_DATASET_NAME_LEN];
 	char errbuf[1024];
 	dmu_replay_record_t drre;
 	int error;
@@ -2793,7 +2793,7 @@ zfs_receive_package(libzfs_handle_t *hdl, int fd, const char *destname,
 			nvlist_t *renamed = NULL;
 			nvpair_t *pair = NULL;
 
-			(void) strlcpy(tofs, destname, ZFS_MAXNAMELEN);
+			(void) strlcpy(tofs, destname, sizeof (tofs));
 			if (flags->isprefix) {
 				struct drr_begin *drrb = &drr->drr_u.drr_begin;
 				int i;
@@ -2802,7 +2802,7 @@ zfs_receive_package(libzfs_handle_t *hdl, int fd, const char *destname,
 					cp = strrchr(drrb->drr_toname, '/');
 					if (cp == NULL) {
 						(void) strlcat(tofs, "/",
-						    ZFS_MAXNAMELEN);
+						    sizeof (tofs));
 						i = 0;
 					} else {
 						i = (cp - drrb->drr_toname);
@@ -2812,7 +2812,7 @@ zfs_receive_package(libzfs_handle_t *hdl, int fd, const char *destname,
 				}
 				/* zfs_receive_one() will create_parents() */
 				(void) strlcat(tofs, &drrb->drr_toname[i],
-				    ZFS_MAXNAMELEN);
+				    sizeof (tofs));
 				*strchr(tofs, '@') = '\0';
 			}
 
@@ -2854,7 +2854,7 @@ zfs_receive_package(libzfs_handle_t *hdl, int fd, const char *destname,
 	 * zfs_receive_one().
 	 */
 	(void) strlcpy(sendfs, drr->drr_u.drr_begin.drr_toname,
-	    ZFS_MAXNAMELEN);
+	    sizeof (sendfs));
 	if ((cp = strchr(sendfs, '@')) != NULL) {
 		*cp = '\0';
 		/*
@@ -3004,7 +3004,7 @@ static void
 recv_ecksum_set_aux(libzfs_handle_t *hdl, const char *target_snap,
     boolean_t resumable)
 {
-	char target_fs[ZFS_MAXNAMELEN];
+	char target_fs[ZFS_MAX_DATASET_NAME_LEN];
 
 	zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
 	    "checksum mismatch or incomplete stream"));
@@ -3207,7 +3207,7 @@ zfs_receive_one(libzfs_handle_t *hdl, int infd, const char *tosnap,
 		if (flags->verbose)
 			(void) printf("found clone origin %s\n", zc.zc_string);
 	} else if (originsnap) {
-		(void) strncpy(zc.zc_string, originsnap, ZFS_MAXNAMELEN);
+		(void) strncpy(zc.zc_string, originsnap, sizeof (zc.zc_string));
 		if (flags->verbose)
 			(void) printf("using provided clone origin %s\n",
 			    zc.zc_string);
@@ -3232,7 +3232,7 @@ zfs_receive_one(libzfs_handle_t *hdl, int infd, const char *tosnap,
 			*cp = '\0';
 		if (cp &&
 		    !zfs_dataset_exists(hdl, zc.zc_name, ZFS_TYPE_DATASET)) {
-			char suffix[ZFS_MAXNAMELEN];
+			char suffix[ZFS_MAX_DATASET_NAME_LEN];
 			(void) strcpy(suffix, strrchr(zc.zc_value, '/'));
 			if (guid_to_name(hdl, zc.zc_name, parent_snapguid,
 			    B_FALSE, zc.zc_value) == 0) {
@@ -3259,7 +3259,7 @@ zfs_receive_one(libzfs_handle_t *hdl, int infd, const char *tosnap,
 		if ((flags->isprefix || (*(chopprefix = drrb->drr_toname +
 		    strlen(sendfs)) != '\0' && *chopprefix != '@')) &&
 		    !zfs_dataset_exists(hdl, zc.zc_name, ZFS_TYPE_DATASET)) {
-			char snap[ZFS_MAXNAMELEN];
+			char snap[ZFS_MAX_DATASET_NAME_LEN];
 			(void) strcpy(snap, strchr(zc.zc_value, '@'));
 			if (guid_to_name(hdl, zc.zc_name, drrb->drr_fromguid,
 			    B_FALSE, zc.zc_value) == 0) {
@@ -3709,7 +3709,7 @@ zfs_receive_impl(libzfs_handle_t *hdl, const char *tosnap,
 	}
 
 	if (DMU_GET_STREAM_HDRTYPE(drrb->drr_versioninfo) == DMU_SUBSTREAM) {
-		char nonpackage_sendfs[ZFS_MAXNAMELEN];
+		char nonpackage_sendfs[ZFS_MAX_DATASET_NAME_LEN];
 		if (sendfs == NULL) {
 			/*
 			 * We were not called from zfs_receive_package(). Get
@@ -3717,7 +3717,8 @@ zfs_receive_impl(libzfs_handle_t *hdl, const char *tosnap,
 			 */
 			char *cp;
 			(void) strlcpy(nonpackage_sendfs,
-			    drr.drr_u.drr_begin.drr_toname, ZFS_MAXNAMELEN);
+			    drr.drr_u.drr_begin.drr_toname,
+			    sizeof (nonpackage_sendfs));
 			if ((cp = strchr(nonpackage_sendfs, '@')) != NULL)
 				*cp = '\0';
 			sendfs = nonpackage_sendfs;
diff --git a/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.c b/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.c
index 09289a6..c1ada8d 100644
--- a/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.c
+++ b/cddl/contrib/opensolaris/lib/libzfs_core/common/libzfs_core.c
@@ -265,7 +265,7 @@ lzc_snapshot(nvlist_t *snaps, nvlist_t *props, nvlist_t **errlist)
 	nvpair_t *elem;
 	nvlist_t *args;
 	int error;
-	char pool[MAXNAMELEN];
+	char pool[ZFS_MAX_DATASET_NAME_LEN];
 
 	*errlist = NULL;
 
@@ -317,7 +317,7 @@ lzc_destroy_snaps(nvlist_t *snaps, boolean_t defer, nvlist_t **errlist)
 	nvpair_t *elem;
 	nvlist_t *args;
 	int error;
-	char pool[MAXNAMELEN];
+	char pool[ZFS_MAX_DATASET_NAME_LEN];
 
 	/* determine the pool name */
 	elem = nvlist_next_nvpair(snaps, NULL);
@@ -344,7 +344,7 @@ lzc_snaprange_space(const char *firstsnap, const char *lastsnap,
 	nvlist_t *args;
 	nvlist_t *result;
 	int err;
-	char fs[MAXNAMELEN];
+	char fs[ZFS_MAX_DATASET_NAME_LEN];
 	char *atp;
 
 	/* determine the fs name */
@@ -409,7 +409,7 @@ lzc_exists(const char *dataset)
 int
 lzc_hold(nvlist_t *holds, int cleanup_fd, nvlist_t **errlist)
 {
-	char pool[MAXNAMELEN];
+	char pool[ZFS_MAX_DATASET_NAME_LEN];
 	nvlist_t *args;
 	nvpair_t *elem;
 	int error;
@@ -456,7 +456,7 @@ lzc_hold(nvlist_t *holds, int cleanup_fd, nvlist_t **errlist)
 int
 lzc_release(nvlist_t *holds, nvlist_t **errlist)
 {
-	char pool[MAXNAMELEN];
+	char pool[ZFS_MAX_DATASET_NAME_LEN];
 	nvpair_t *elem;
 
 	/* determine the pool name */
@@ -743,7 +743,7 @@ lzc_bookmark(nvlist_t *bookmarks, nvlist_t **errlist)
 {
 	nvpair_t *elem;
 	int error;
-	char pool[MAXNAMELEN];
+	char pool[ZFS_MAX_DATASET_NAME_LEN];
 
 	/* determine the pool name */
 	elem = nvlist_next_nvpair(bookmarks, NULL);
@@ -805,7 +805,7 @@ lzc_destroy_bookmarks(nvlist_t *bmarks, nvlist_t **errlist)
 {
 	nvpair_t *elem;
 	int error;
-	char pool[MAXNAMELEN];
+	char pool[ZFS_MAX_DATASET_NAME_LEN];
 
 	/* determine the pool name */
 	elem = nvlist_next_nvpair(bmarks, NULL);