From: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
Subject: fs: ocfs2: fix a possible null-pointer dereference in ocfs2_write_end_nolock()
In ocfs2_write_end_nolock(), there are an if statement on lines 1976,
2047 and 2058, to check whether handle is NULL:
if (handle)
When handle is NULL, it is used on line 2045:
ocfs2_update_inode_fsync_trans(handle, inode, 1);
oi->i_sync_tid = handle->h_transaction->t_tid;
Thus, a possible null-pointer dereference may occur.
To fix this bug, handle is checked before calling
ocfs2_update_inode_fsync_trans().
This bug is found by a static analysis tool STCheck written by us.
Link: http://lkml.kernel.org/r/20190726033705.32307-1-baijiaju1990@xxxxxxxxx
Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
Reviewed-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
Cc: Mark Fasheh <mark@xxxxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Cc: Changwei Ge <gechangwei@xxxxxxx>
Cc: Gang He <ghe@xxxxxxxx>
Cc: Jun Piao <piaojun@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ocfs2/aops.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/ocfs2/aops.c~fs-ocfs2-fix-a-possible-null-pointer-dereference-in-ocfs2_write_end_nolock
+++ a/fs/ocfs2/aops.c
@@ -2049,7 +2049,8 @@ out_write_size:
inode->i_mtime = inode->i_ctime = current_time(inode);
di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
- ocfs2_update_inode_fsync_trans(handle, inode, 1);
+ if (handle)
+ ocfs2_update_inode_fsync_trans(handle, inode, 1);
}
if (handle)
ocfs2_journal_dirty(handle, wc->w_di_bh);
_
