kern/60053: [PATCH] fsck_ext2fs: add sanity check for EXT2_HUGE_FILE without HUGE_FILE feature

["ssszcmawo%gmail.com@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         60053
>Category:       kern
>Synopsis:       [PATCH] fsck_ext2fs: add sanity check for EXT2_HUGE_FILE without HUGE_FILE feature
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Tue Mar 03 21:35:01 +0000 2026
>Originator:     ssszcmawo
>Release:        11.95.5
>Organization:
>Environment:
n/a
>Description:
Add consistency check in inonblock(): reject inodes that have the
EXT2_HUGE_FILE flag set without the corresponding EXT2F_ROCOMPAT_HUGE_FILE
feature in the superblock. Previously such inconsistency was silently
accepted. Also added a warning when directory entry names are truncated due to length > MAXPATHLEN.
>How-To-Repeat:

>Fix:
>From defc50de65403e684597ffd22389055eaa35cbdd Mon Sep 17 00:00:00 2001
From: ssszcmawo <belan2470%gmail.com@localhost>
Date: Tue, 3 Mar 2026 15:29:53 +0100
Subject: [PATCH] add additional check for huge files and comments

---
 sbin/fsck_ext2fs/inode.c | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/sbin/fsck_ext2fs/inode.c b/sbin/fsck_ext2fs/inode.c
index 97f02b84a..c12857d5b 100644
--- a/sbin/fsck_ext2fs/inode.c
+++ b/sbin/fsck_ext2fs/inode.c
@@ -600,7 +600,8 @@ findname(struct inodesc *idesc)
 	/* from utilities.c namebuf[] variable */
 	char *buf = __UNCONST(idesc->id_name);
 	if (namlen > MAXPATHLEN) {
-		/* XXX: Prevent overflow but don't fix */
+		/* XXX: Prevent overflow but don't fix */	
+		printf("entry name truncated");
 		namlen = MAXPATHLEN;
 	}
 
@@ -755,25 +756,34 @@ freeino(ino_t ino)
 	n_files--;
 }
 
+/*
+ * read the number of block from inode
+ */
 uint64_t
 inonblock(struct ext2fs_dinode *dp)
 {
 	uint64_t nblock;
-
-	/* XXX check for EXT2_HUGE_FILE without EXT2F_ROCOMPAT_HUGE_FILE? */
+	uint32_t flags;
 
 	nblock = fs2h32(dp->e2di_nblock);
+	flags = fs2h32(dp->e2di_flags);
 
-	if ((sblock.e2fs.e2fs_features_rocompat & EXT2F_ROCOMPAT_HUGE_FILE)) {
-		nblock |= (uint64_t)fs2h16(dp->e2di_nblock_high) << 32;
-		if (fs2h32(dp->e2di_flags) & EXT2_HUGE_FILE) {
-			nblock = EXT2_FSBTODB(&sblock, nblock);
-		}
+	if ((flags & EXT2_HUGE_FILE) &&
+		!(sblock.e2fs.e2fs_features_rocompat & EXT2F_ROCOMPAT_HUGE_FILE)) {
+	    pfatal("inconsistent filesystem");
 	}
+	if (sblock.e2fs.e2fs_features_rocompat & EXT2F_ROCOMPAT_HUGE_FILE)
+	    nblock |= (uint64_t)fs2h16(dp->e2di_nblock_high) << 32;
+
+	if (flags & EXT2_HUGE_FILE)
+	    nblock = EXT2_FSBTODB(&sblock, nblock);
 
 	return nblock;
 }
 
+/*
+ * set the number of block in an inode
+ */
 void
 inosnblock(struct ext2fs_dinode *dp, uint64_t nblock)
 {
-- 
2.47.3