diff --git a/sys/cam/ata/ata_da.c b/sys/cam/ata/ata_da.c
--- a/sys/cam/ata/ata_da.c
+++ b/sys/cam/ata/ata_da.c
@@ -3424,6 +3424,7 @@
 	u_int64_t lbasize48;
 	u_int32_t lbasize;
 	u_int maxio, d_flags;
+	size_t tmpsize;
 
 	dp->secsize = ata_logical_sector_size(&cgd->ident_data);
 	if ((cgd->ident_data.atavalid & ATA_FLAG_54_58) &&
@@ -3487,10 +3488,25 @@
 		softc->flags |= ADA_FLAG_UNMAPPEDIO;
 	}
 	softc->disk->d_flags = d_flags;
-	strlcpy(softc->disk->d_descr, cgd->ident_data.model,
-	    MIN(sizeof(softc->disk->d_descr), sizeof(cgd->ident_data.model)));
-	strlcpy(softc->disk->d_ident, cgd->ident_data.serial,
-	    MIN(sizeof(softc->disk->d_ident), sizeof(cgd->ident_data.serial)));
+
+	/*
+	 * ata_param_fixup will strip trailing padding spaces and add a NUL,
+	 * but if the field has no padding (as is common for serial numbers)
+	 * there will still be no NUL terminator. We cannot use strlcpy, since
+	 * it keeps reading src until it finds a NUL in order to compute the
+	 * return value (and will truncate the final character due to having a
+	 * single dsize rather than separate ssize and dsize), and strncpy does
+	 * not add a NUL to the destination if it reaches the character limit.
+	 */
+	tmpsize = MIN(sizeof(softc->disk->d_descr) - 1,
+	    sizeof(cgd->ident_data.model));
+	memcpy(softc->disk->d_descr, cgd->ident_data.model, tmpsize);
+	softc->disk->d_descr[tmpsize] = '\0';
+
+	tmpsize = MIN(sizeof(softc->disk->d_ident) - 1,
+	    sizeof(cgd->ident_data.serial));
+	memcpy(softc->disk->d_ident, cgd->ident_data.serial, tmpsize);
+	softc->disk->d_ident[tmpsize] = '\0';
 
 	softc->disk->d_sectorsize = softc->params.secsize;
 	softc->disk->d_mediasize = (off_t)softc->params.sectors *