#syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 24172e0d79900908cf5ebf366600616d29c9b417

Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
---
 fs/ocfs2/slot_map.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/fs/ocfs2/slot_map.c b/fs/ocfs2/slot_map.c
index e544c704b583..79f9d1753bc1 100644
--- a/fs/ocfs2/slot_map.c
+++ b/fs/ocfs2/slot_map.c
@@ -193,6 +193,17 @@ static int ocfs2_update_disk_slot(struct ocfs2_super *osb,
 	else
 		ocfs2_update_disk_slot_old(si, slot_num, &bh);
 	spin_unlock(&osb->osb_lock);
+	if (bh->b_blocknr < OCFS2_SUPER_BLOCK_BLKNO) {
+		status = ocfs2_error(osb->sb,
+				     "Invalid Slot Map Buffer Head "
+				     "Block Number : %llu, Should be >= %d",
+				     le16_to_cpu(bh->b_blocknr),
+				     le16_to_cpu((int)OCFS2_SUPER_BLOCK_BLKNO));
+		if(!status) {
+			return -EIO;
+		}
+		return status;
+	}
 
 	status = ocfs2_write_block(osb, bh, INODE_CACHE(si->si_inode));
 	if (status < 0)

base-commit: 24172e0d79900908cf5ebf366600616d29c9b417
-- 
2.43.0

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+c818e5c4559444f88aa0@syzkaller.appspotmail.com
Tested-by: syzbot+c818e5c4559444f88aa0@syzkaller.appspotmail.com

Tested on:

commit:         24172e0d Merge tag 'arm64-fixes' of git://git.kernel.o..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=12b54992580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=41ad820f608cb833
dashboard link: https://syzkaller.appspot.com/bug?extid=c818e5c4559444f88aa0
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=11da421a580000

Note: testing is done by a robot and is best-effort only.