ocfs2: pass u64 to ocfs2_truncate_inline maybe overflow

Syzbot reported a kernel BUG in ocfs2_truncate_inline.  There are two
reasons for this: first, the parameter value passed is greater than
ocfs2_max_inline_data_with_xattr, second, the start and end parameters of
ocfs2_truncate_inline are "unsigned int".

So, we need to add a sanity check for byte_start and byte_len right before
ocfs2_truncate_inline() in ocfs2_remove_inode_range(), if they are greater
than ocfs2_max_inline_data_with_xattr return -EINVAL.

Link: https://lkml.kernel.org/r/tencent_D48DB5122ADDAEDDD11918CFB68D93258C07@qq.com
Fixes: 1afc32b95233 ("ocfs2: Write support for inline data")
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Reported-by: syzbot+81092778aac03460d6b7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=81092778aac03460d6b7
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 58887456e3c516d6f0fe59a812b4a866679fe8c0..06af21982c16aba9d7970d43c0c4ffd860ab0aa0 100644 (file)
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1787,6 +1787,14 @@ int ocfs2_remove_inode_range(struct inode *inode,
                return 0;
 
        if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
+               int id_count = ocfs2_max_inline_data_with_xattr(inode->i_sb, di);
+
+               if (byte_start > id_count || byte_start + byte_len > id_count) {
+                       ret = -EINVAL;
+                       mlog_errno(ret);
+                       goto out;
+               }
+
                ret = ocfs2_truncate_inline(inode, di_bh, byte_start,
                                            byte_start + byte_len, 0);
                if (ret) {