dm-integrity: limit MAX_TAG_SIZE to 255

JIRA: https://issues.redhat.com/browse/RHEL-119008
Upstream Status: kernel/git/torvalds/linux.git

commit 77b8e6f
Author: Mikulas Patocka <mpatocka@redhat.com>
Date:   Mon Sep 8 15:52:02 2025 +0200

    dm-integrity: limit MAX_TAG_SIZE to 255

    MAX_TAG_SIZE was 0x1a8 and it may be truncated in the "bi->metadata_size
    = ic->tag_size" assignment. We need to limit it to 255.

    Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>

Author: bmarzins

drivers/md/dm-integrity.c

@@ -133,7 +133,7 @@ struct journal_sector {
 	commit_id_t commit_id;
 };
 
-#define MAX_TAG_SIZE			(JOURNAL_SECTOR_DATA - JOURNAL_MAC_PER_SECTOR - offsetof(struct journal_entry, last_bytes[MAX_SECTORS_PER_BLOCK]))
+#define MAX_TAG_SIZE			255
 
 #define METADATA_PADDING_SECTORS	8