Avoid core dump on invalid redaction bookmark

libzfs aborts and dumps core on EINVAL from the kernel when trying to
do a redacted send with a bookmark that is not a redaction bookmark.

Move redacted bookmark validation into libzfs.

Check if the bookmark given for redactions is actually a redaction
bookmark.  Print an error message and exit gracefully if it is not.

Don't abort on EINVAL in zfs_send_one.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10138

cmd/zfs/zfs_main.c

@@ -4408,24 +4408,6 @@ zfs_do_send(int argc, char **argv)
 	if (!(flags.replicate || flags.doall)) {
 		char frombuf[ZFS_MAX_DATASET_NAME_LEN];
 
-		if (redactbook != NULL) {
-			if (strchr(argv[0], '@') == NULL) {
-				(void) fprintf(stderr, gettext("Error: Cannot "
-				    "do a redacted send to a filesystem.\n"));
-				return (1);
-			}
-			if (strchr(redactbook, '#') != NULL) {
-				(void) fprintf(stderr, gettext("Error: "
-				    "redaction bookmark argument must "
-				    "not contain '#'\n"));
-				return (1);
-			}
-		}
-
-		zhp = zfs_open(g_zfs, argv[0], ZFS_TYPE_DATASET);
-		if (zhp == NULL)
-			return (1);
-
 		if (fromname != NULL && (strchr(fromname, '#') == NULL &&
 		    strchr(fromname, '@') == NULL)) {
 			/*
@@ -4454,6 +4436,10 @@ zfs_do_send(int argc, char **argv)
 			(void) strlcat(frombuf, tmpbuf, sizeof (frombuf));
 			fromname = frombuf;
 		}
+
+		zhp = zfs_open(g_zfs, argv[0], ZFS_TYPE_DATASET);
+		if (zhp == NULL)
+			return (1);
 		err = zfs_send_one(zhp, fromname, STDOUT_FILENO, &flags,
 		    redactbook);
 		zfs_close(zhp);

lib/libzfs/libzfs_sendrecv.c

@@ -2816,6 +2816,7 @@ zfs_send_one(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
 {
 	int err;
 	libzfs_handle_t *hdl = zhp->zfs_hdl;
+	char *name = zhp->zfs_name;
 	int orig_fd = fd;
 	pthread_t ddtid, ptid;
 	progress_arg_t pa = { 0 };
@@ -2823,7 +2824,7 @@ zfs_send_one(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
 
 	char errbuf[1024];
 	(void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
-	    "warning: cannot send '%s'"), zhp->zfs_name);
+	    "warning: cannot send '%s'"), name);
 
 	if (from != NULL && strchr(from, '@')) {
 		zfs_handle_t *from_zhp = zfs_open(hdl, from,
@@ -2839,6 +2840,44 @@ zfs_send_one(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
 		zfs_close(from_zhp);
 	}
 
+	if (redactbook != NULL) {
+		char bookname[ZFS_MAX_DATASET_NAME_LEN];
+		nvlist_t *redact_snaps;
+		zfs_handle_t *book_zhp;
+		char *at, *pound;
+		int dsnamelen;
+
+		pound = strchr(redactbook, '#');
+		if (pound != NULL)
+			redactbook = pound + 1;
+		at = strchr(name, '@');
+		if (at == NULL) {
+			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+			    "cannot do a redacted send to a filesystem"));
+			return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
+		}
+		dsnamelen = at - name;
+		if (snprintf(bookname, sizeof (bookname), "%.*s#%s",
+		    dsnamelen, name, redactbook)
+		    >= sizeof (bookname)) {
+			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+			    "invalid bookmark name"));
+			return (zfs_error(hdl, EZFS_INVALIDNAME, errbuf));
+		}
+		book_zhp = zfs_open(hdl, bookname, ZFS_TYPE_BOOKMARK);
+		if (book_zhp == NULL)
+			return (-1);
+		if (nvlist_lookup_nvlist(book_zhp->zfs_props,
+		    zfs_prop_to_name(ZFS_PROP_REDACT_SNAPS),
+		    &redact_snaps) != 0 || redact_snaps == NULL) {
+			zfs_close(book_zhp);
+			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+			    "not a redaction bookmark"));
+			return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
+		}
+		zfs_close(book_zhp);
+	}
+
 	/*
 	 * Send fs properties
 	 */
@@ -2909,7 +2948,7 @@ zfs_send_one(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
 		}
 	}
 
-	err = lzc_send_redacted(zhp->zfs_name, from, fd,
+	err = lzc_send_redacted(name, from, fd,
 	    lzc_flags_from_sendflags(flags), redactbook);
 
 	if (flags->progress) {
@@ -2948,7 +2987,7 @@ zfs_send_one(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
 
 		case ENOENT:
 		case ESRCH:
-			if (lzc_exists(zhp->zfs_name)) {
+			if (lzc_exists(name)) {
 				zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
 				    "incremental source (%s) does not exist"),
 				    from);
@@ -2967,7 +3006,9 @@ zfs_send_one(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
 			return (zfs_error(hdl, EZFS_BUSY, errbuf));
 
 		case EDQUOT:
+		case EFAULT:
 		case EFBIG:
+		case EINVAL:
 		case EIO:
 		case ENOLINK:
 		case ENOSPC:
@@ -2975,7 +3016,6 @@ zfs_send_one(zfs_handle_t *zhp, const char *from, int fd, sendflags_t *flags,
 		case ENXIO:
 		case EPIPE:
 		case ERANGE:
-		case EFAULT:
 		case EROFS:
 			zfs_error_aux(hdl, strerror(errno));
 			return (zfs_error(hdl, EZFS_BADBACKUP, errbuf));

tests/zfs-tests/tests/functional/cli_root/zfs_bookmark/zfs_bookmark_cliargs.ksh

@@ -222,12 +222,12 @@ log_must zfs redact "$DATASET@$TESTSNAP" "$TESTBM" "$DATASET@$TESTSNAP2"
 log_must eval "zfs get all $DATASET#$TESTBM | grep redact_snaps"
 ## copy the redaction bookmark
 log_must zfs bookmark "$DATASET#$TESTBM" "#$TESTBMCOPY"
-log_must eval "zfs send --redact "$TESTBMCOPY" -i $DATASET@$TESTSNAP $DATASET@$TESTSNAP2 2>&1 | head -n 100 | grep 'internal error: Invalid argument'"
 log_mustnot eval "zfs get all $DATASET#$TESTBMCOPY | grep redact_snaps"
+log_must eval "zfs send --redact "$TESTBMCOPY" -i $DATASET@$TESTSNAP $DATASET@$TESTSNAP2 2>&1 | head -n 100 | grep 'not a redaction bookmark'"
 # try the above again after destroying the source bookmark, preventive measure for future work
 log_must zfs destroy "$DATASET#$TESTBM"
-log_must eval "zfs send --redact "$TESTBMCOPY" -i $DATASET@$TESTSNAP $DATASET@$TESTSNAP2 2>&1 | head -n 100 | grep 'internal error: Invalid argument'"
 log_mustnot eval "zfs get all $DATASET#$TESTBMCOPY | grep redact_snaps"
+log_must eval "zfs send --redact "$TESTBMCOPY" -i $DATASET@$TESTSNAP $DATASET@$TESTSNAP2 2>&1 | head -n 100 | grep 'not a redaction bookmark'"
 ## cleanup
 log_must eval "destroy_dataset $DATASET@$TESTSNAP2"
 log_must zfs destroy "$DATASET#$TESTBMCOPY"

tests/zfs-tests/tests/functional/redacted_send/redacted_negative.ksh

@@ -79,7 +79,7 @@ log_mustnot zfs redact testpool2/recvfs@snap2 book7 testpool2/recvfs@snap
 
 # Non-redaction bookmark cannot be sent and produces invalid argument error
 log_must zfs bookmark "$sendfs@snap1" "$sendfs#book8"
-log_must eval "zfs send --redact book8 -i $sendfs@snap1 $sendfs@snap2 2>&1 | head -n 100 | grep 'internal error: Invalid argument'"
+log_must eval "zfs send --redact book8 -i $sendfs@snap1 $sendfs@snap2 2>&1 | head -n 100 | grep 'not a redaction bookmark'"
 
 # Error messages for common usage errors
 log_mustnot_expect "not contain '#'"    zfs redact $sendfs@snap1 \#book $sendfs@snap2