illumos#16463 zfs_ioc_recv leaks nvlist

In https://www.illumos.org/issues/16463 it was observed that
an nvlist was being leaked in zfs_ioc_recv() due a missing
call to nvlist_free for "hidden_args".
For OpenZFS the same issue exists in zfs_ioc_recv_new() and
is addressed by this PR.

This change also properly frees nvlists in the unlikely
event that a call to get_nvlist() fails.

Signed-off-by: Andy Fiddaman <[email protected]>

module/zfs/zfs_ioctl.c

@@ -40,6 +40,7 @@
  * Copyright (c) 2019, 2020 by Christian Schwarz. All rights reserved.
  * Copyright (c) 2019, 2021, Klara Inc.
  * Copyright (c) 2019, Allan Jude
+ * Copyright 2024 Oxide Computer Company
  */
 
 /*
@@ -5345,22 +5346,25 @@ zfs_ioc_recv(zfs_cmd_t *zc)
 
 	if (dataset_namecheck(zc->zc_value, NULL, NULL) != 0 ||
 	    strchr(zc->zc_value, '@') == NULL ||
-	    strchr(zc->zc_value, '%'))
+	    strchr(zc->zc_value, '%') != NULL) {
 		return (SET_ERROR(EINVAL));
+	}
 
 	(void) strlcpy(tofs, zc->zc_value, sizeof (tofs));
 	tosnap = strchr(tofs, '@');
 	*tosnap++ = '\0';
 
 	if (zc->zc_nvlist_src != 0 &&
 	    (error = get_nvlist(zc->zc_nvlist_src, zc->zc_nvlist_src_size,
-	    zc->zc_iflags, &recvdprops)) != 0)
-		return (error);
+	    zc->zc_iflags, &recvdprops)) != 0) {
+		goto out;
+	}
 
 	if (zc->zc_nvlist_conf != 0 &&
 	    (error = get_nvlist(zc->zc_nvlist_conf, zc->zc_nvlist_conf_size,
-	    zc->zc_iflags, &localprops)) != 0)
-		return (error);
+	    zc->zc_iflags, &localprops)) != 0) {
+		goto out;
+	}
 
 	if (zc->zc_string[0])
 		origin = zc->zc_string;
@@ -5372,8 +5376,6 @@ zfs_ioc_recv(zfs_cmd_t *zc)
 	error = zfs_ioc_recv_impl(tofs, tosnap, origin, recvdprops, localprops,
 	    NULL, zc->zc_guid, B_FALSE, B_FALSE, zc->zc_cookie, &begin_record,
 	    &zc->zc_cookie, &zc->zc_obj, &errors);
-	nvlist_free(recvdprops);
-	nvlist_free(localprops);
 
 	/*
 	 * Now that all props, initial and delayed, are set, report the prop
@@ -5389,7 +5391,10 @@ zfs_ioc_recv(zfs_cmd_t *zc)
 		error = SET_ERROR(EINVAL);
 	}
 
+out:
 	nvlist_free(errors);
+	nvlist_free(recvdprops);
+	nvlist_free(localprops);
 
 	return (error);
 }
@@ -5456,8 +5461,9 @@ zfs_ioc_recv_new(const char *fsname, nvlist_t *innvl, nvlist_t *outnvl)
 
 	if (dataset_namecheck(snapname, NULL, NULL) != 0 ||
 	    strchr(snapname, '@') == NULL ||
-	    strchr(snapname, '%'))
+	    strchr(snapname, '%') != NULL) {
 		return (SET_ERROR(EINVAL));
+	}
 
 	(void) strlcpy(tofs, snapname, sizeof (tofs));
 	tosnap = strchr(tofs, '@');
@@ -5481,15 +5487,15 @@ zfs_ioc_recv_new(const char *fsname, nvlist_t *innvl, nvlist_t *outnvl)
 	/* we still use "props" here for backwards compatibility */
 	error = nvlist_lookup_nvlist(innvl, "props", &recvprops);
 	if (error && error != ENOENT)
-		return (error);
+		goto out;
 
 	error = nvlist_lookup_nvlist(innvl, "localprops", &localprops);
 	if (error && error != ENOENT)
-		return (error);
+		goto out;
 
 	error = nvlist_lookup_nvlist(innvl, ZPOOL_HIDDEN_ARGS, &hidden_args);
 	if (error && error != ENOENT)
-		return (error);
+		goto out;
 
 	error = zfs_ioc_recv_impl(tofs, tosnap, origin, recvprops, localprops,
 	    hidden_args, force, heal, resumable, input_fd, begin_record,
@@ -5499,9 +5505,11 @@ zfs_ioc_recv_new(const char *fsname, nvlist_t *innvl, nvlist_t *outnvl)
 	fnvlist_add_uint64(outnvl, "error_flags", errflags);
 	fnvlist_add_nvlist(outnvl, "errors", errors);
 
+out:
 	nvlist_free(errors);
 	nvlist_free(recvprops);
 	nvlist_free(localprops);
+	nvlist_free(hidden_args);
 
 	return (error);
 }