+ ocfs2-reject-inconsistent-xattr-bucket-during-defrag.patch added to mm-nonmm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: ocfs2: reject inconsistent xattr bucket during defrag
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     ocfs2-reject-inconsistent-xattr-bucket-during-defrag.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ocfs2-reject-inconsistent-xattr-bucket-during-defrag.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Joseph Qi <joseph.qi@linux.alibaba.com>
Subject: ocfs2: reject inconsistent xattr bucket during defrag
Date: Thu, 3 Sep 2026 21:13:13 +0800

ocfs2_defrag_xattr_bucket() has two mlog_bug_on_msg() checks that assume
the name/value pairs in a bucket are disjoint and that xh_free_start is
not below the compacted region.

ocfs2_validate_xattr_bucket() only checks each entry in isolation, so a
corrupt bucket holding overlapping entries, or one with an inflated
xh_free_start, passes validation and then hits BUG() in defrag when a
setxattr triggers it.

Defrag works on a linear copy of the bucket and does not touch the real
blocks before the copy back, so the checks can return an error instead of
calling BUG().

Link: https://lore.kernel.org/20260903131313.2396208-3-joseph.qi@linux.alibaba.com
Fixes: 012255961c9e ("ocfs2: Enable xattr set in index btree")
Signed-off-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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/ocfs2/xattr.c |   16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

--- a/fs/ocfs2/xattr.c~ocfs2-reject-inconsistent-xattr-bucket-during-defrag
+++ a/fs/ocfs2/xattr.c
@@ -4804,16 +4804,22 @@ static int ocfs2_defrag_xattr_bucket(str
 			memmove(bucket_buf + end - len,
 				bucket_buf + offset, len);
 			xe->xe_name_offset = cpu_to_le16(end - len);
+		} else if (end < offset + len) {
+			ret = ocfs2_error(inode->i_sb,
+					  "Defrag check failed for bucket %llu\n",
+					  (unsigned long long)blkno);
+			goto out;
 		}
 
-		mlog_bug_on_msg(end < offset + len, "Defrag check failed for "
-				"bucket %llu\n", (unsigned long long)blkno);
-
 		end -= len;
 	}
 
-	mlog_bug_on_msg(xh_free_start > end, "Defrag check failed for "
-			"bucket %llu\n", (unsigned long long)blkno);
+	if (xh_free_start > end) {
+		ret = ocfs2_error(inode->i_sb,
+				  "Defrag check failed for bucket %llu\n",
+				  (unsigned long long)blkno);
+		goto out;
+	}
 
 	if (xh_free_start == end)
 		goto out;
_

Patches currently in -mm which might be from joseph.qi@linux.alibaba.com are

ocfs2-fix-deadlock-in-inline-data-truncate-transactions.patch
ocfs2-exit-recovery-thread-on-mount-error-path.patch
ocfs2-free-replay-slots-in-ocfs2_recovery_exit.patch
ocfs2-defer-suballocator-block-group-reclaim-to-workqueue.patch
ocfs2-restrict-ocfs2_invalid_slot-suballoc-slot-to-system-inodes.patch
ocfs2-validate-suballoc-bit-during-inode-read.patch
ocfs2-validate-suballoc-slot-and-bit-of-xattr-and-dir-index-blocks.patch
ocfs2-validate-suballoc-slot-and-bit-of-extent-and-refcount-blocks.patch
ocfs2-allow-xattr-bucket-entries-to-span-multiple-blocks.patch
ocfs2-reject-inconsistent-xattr-bucket-during-defrag.patch