[to-be-updated] ocfs2-reject-dinodes-whose-i_rdev-disagrees-with-the-file-type.patch removed from -mm tree

[to-be-updated] ocfs2-reject-dinodes-whose-i_rdev-disagrees-with-the-file-type.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: ocfs2: reject dinodes whose i_rdev disagrees with the file type
has been removed from the -mm tree.  Its filename was
     ocfs2-reject-dinodes-whose-i_rdev-disagrees-with-the-file-type.patch

This patch was dropped because an updated version will be issued

------------------------------------------------------
From: Michael Bommarito <michael.bommarito@gmail.com>
Subject: ocfs2: reject dinodes whose i_rdev disagrees with the file type
Date: Sun, 17 May 2026 07:10:13 -0400

id1.dev1.i_rdev is the device-number arm of the ocfs2_dinode id1 union and
is only meaningful for character and block device inodes.  For any other
user-visible file type the on-disk value must be zero.

ocfs2_populate_inode() currently runs

    inode->i_rdev = huge_decode_dev(le64_to_cpu(fe->id1.dev1.i_rdev));

unconditionally, before the S_IFMT switch decides whether the inode is a
special file.  As a result, an i_rdev value present on a non-device inode
is silently published into the in-core inode.  A subsequent forced re-read
or in-core mode mutation (cluster peer with raw write access to the shared
LUN, on-disk corruption, or a separately forged dinode) can then expose
the attacker- controlled device number to init_special_inode() without
ever showing an unusual i_mode at validation time.

System inodes (OCFS2_SYSTEM_FL) legitimately use the bitmap1 and journal1
arms of the same union: allocator inodes encode i_used / i_total in the
bitmap1 arm and the journal encodes ij_flags / ij_recovery_generation in
the journal1 arm.  Those byte sequences are not an i_rdev and a non-zero
pattern there is the on-disk norm, not an integrity violation.  Restrict
the cross- check to non-system inodes; that is the full surface where
i_rdev semantics apply and is also the full surface an unprivileged
consumer of the volume can see.

Following the i_mode canonicalisation in patch 1, S_ISCHR / S_ISBLK covers
the whole device-inode space; this check operates correctly on its own,
but the canonicalised i_mode makes the predicate exhaustive.

Link: https://lore.kernel.org/20260517111015.3187935-3-michael.bommarito@gmail.com
Fixes: b657c95c1108 ("ocfs2: Wrap inode block reads in a dedicated function.")
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Assisted-by: Claude:claude-opus-4-7
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Heming Zhao <heming.zhao@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/ocfs2/inode.c |   38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

--- a/fs/ocfs2/inode.c~ocfs2-reject-dinodes-whose-i_rdev-disagrees-with-the-file-type
+++ a/fs/ocfs2/inode.c
@@ -1533,6 +1533,44 @@ int ocfs2_validate_inode_block(struct su
 		}
 	}
 
+	/*
+	 * id1.dev1.i_rdev is the device-number arm of the id1 union and
+	 * is only meaningful for character and block device inodes.  For
+	 * any other regular user-visible file type the on-disk value
+	 * must be zero.  ocfs2_populate_inode() currently runs
+	 *
+	 *     inode->i_rdev = huge_decode_dev(le64_to_cpu(fe->id1.dev1.i_rdev));
+	 *
+	 * unconditionally, before the S_IFMT switch decides whether the
+	 * inode is a special file.  As a result, an i_rdev value present
+	 * on a non-device inode is silently published into the in-core
+	 * inode; a subsequent forced re-read or in-core mode mutation
+	 * (cluster peer with raw write access to the shared LUN,
+	 * on-disk corruption, or a separately forged dinode) can then
+	 * expose the attacker-controlled device number to
+	 * init_special_inode() without ever showing an unusual i_mode
+	 * at validation time.
+	 *
+	 * System inodes (OCFS2_SYSTEM_FL) legitimately use the bitmap1
+	 * and journal1 arms of the same union (allocator i_used /
+	 * i_total counters and the journal ij_flags /
+	 * ij_recovery_generation pair); those bytes are not an i_rdev
+	 * and must not be checked here.  Restrict the cross-check to
+	 * non-system inodes, which is the full attacker-controllable
+	 * surface.
+	 */
+	if (!(le32_to_cpu(di->i_flags) & OCFS2_SYSTEM_FL) &&
+	    !S_ISCHR(le16_to_cpu(di->i_mode)) &&
+	    !S_ISBLK(le16_to_cpu(di->i_mode)) &&
+	    di->id1.dev1.i_rdev != 0) {
+		rc = ocfs2_error(sb,
+				 "Invalid dinode #%llu: non-device mode 0%o with i_rdev %llu\n",
+				 (unsigned long long)bh->b_blocknr,
+				 le16_to_cpu(di->i_mode),
+				 (unsigned long long)le64_to_cpu(di->id1.dev1.i_rdev));
+		goto bail;
+	}
+
 	if (le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL) {
 		struct ocfs2_inline_data *data = &di->id2.i_data;
 
_

Patches currently in -mm which might be from michael.bommarito@gmail.com are

ocfs2-reject-regular-files-with-non-zero-i_size-and-zero-i_clusters.patch