ocfs2: validate inline xattr header before checking outside values

[BUG]
A corrupt inline xattr header can make
ocfs2_has_inline_xattr_value_outside() walk xh_count from an unchecked
header while refcount-tree teardown decides whether inline xattrs still
point outside the inode body.

[CAUSE]
ocfs2_has_inline_xattr_value_outside() still computed the inline header
directly from di->i_xattr_inline_size and immediately iterated xh_count.
That is the same unchecked metadata boundary as the ibody lookup bug.

[FIX]
Reuse the shared inline-header helper before iterating xh_count. Because
this helper returns a boolean-style answer to its caller, treat a corrupt
header conservatively as "has outside values" instead of walking it.

Link: https://lore.kernel.org/20260508085914.61647-3-gality369@gmail.com
Signed-off-by: ZhengYuan Huang <gality369@gmail.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Heming Zhao <heming.zhao@suse.com>
Cc: Jia-Ju Bai <baijiaju1990@gmail.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: Zixuan Fu <r33s3n6@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 3a5a17cdcf7eb93a39e808184f85ef1ba50f71ba..05f6f0a886cf2633434bd8ccc17ddd9babd4df8e 100644 (file)
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -989,11 +989,12 @@ int ocfs2_has_inline_xattr_value_outside(struct inode *inode,
                                         struct ocfs2_dinode *di)
 {
        struct ocfs2_xattr_header *xh;
+       int ret;
        int i;
 
-       xh = (struct ocfs2_xattr_header *)
-                ((void *)di + inode->i_sb->s_blocksize -
-                le16_to_cpu(di->i_xattr_inline_size));
+       ret = ocfs2_xattr_ibody_lookup_header(inode, di, &xh);
+       if (ret)
+               return 1;
 
        for (i = 0; i < le16_to_cpu(xh->xh_count); i++)
                if (!ocfs2_xattr_is_local(&xh->xh_entries[i]))