diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index f8b9b47e8b24..7b6d6378a3b8 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -298,6 +298,17 @@ void persistent_ram_save_old(struct persistent_ram_zone *prz)
 	if (!size)
 		return;
 
+	/*
+	 * If the existing buffer is differently sized, free it so a new
+	 * one is allocated. This can happen when persistent_ram_save_old()
+	 * is called early in boot and later for a timer-triggered
+	 * survivable crash when the crash dumps don't match in size
+	 * (which would be extremely unlikely given kmsg buffers usually
+	 * exceed prz buffer sizes).
+	 */
+	if (prz->old_log && prz->old_log_size != size)
+		persistent_ram_free_old(prz);
+
 	if (!prz->old_log) {
 		persistent_ram_ecc_old(prz);
 		prz->old_log = kvzalloc(size, GFP_KERNEL);