From ccc4e86d1c24260c18ae94541198c3711c140da6 Mon Sep 17 00:00:00 2001 From: Edward Adam Davis Date: Tue, 11 Nov 2025 19:05:42 +0800 Subject: [PATCH] fs/ntfs3: Prevent memory leaks in add sub record If a rb node with the same ino already exists in the rb tree, the newly alloced mft_inode in ni_add_subrecord() will not have its memory cleaned up, which leads to the memory leak issue reported by syzbot. The best option to avoid this issue is to put the newly alloced mft node when a rb node with the same ino already exists in the rb tree and return the rb node found in the rb tree to the parent layer. syzbot reported: BUG: memory leak unreferenced object 0xffff888110bef280 (size 128): backtrace (crc 126a088f): ni_add_subrecord+0x31/0x180 fs/ntfs3/frecord.c:317 ntfs_look_free_mft+0xf0/0x790 fs/ntfs3/fsntfs.c:715 BUG: memory leak unreferenced object 0xffff888109093400 (size 1024): backtrace (crc 7197c55e): mi_init+0x2b/0x50 fs/ntfs3/record.c:105 mi_format_new+0x40/0x220 fs/ntfs3/record.c:422 Fixes: 4342306f0f0d ("fs/ntfs3: Add file operations and implementation") Reported-by: syzbot+3932ccb896e06f7414c9@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis Signed-off-by: Konstantin Komarov --- fs/ntfs3/frecord.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/ntfs3/frecord.c b/fs/ntfs3/frecord.c index 9881d7dce93d..641ddaf8d4a0 100644 --- a/fs/ntfs3/frecord.c +++ b/fs/ntfs3/frecord.c @@ -325,8 +325,10 @@ bool ni_add_subrecord(struct ntfs_inode *ni, CLST rno, struct mft_inode **mi) mi_get_ref(&ni->mi, &m->mrec->parent_ref); - ni_add_mi(ni, m); - *mi = m; + *mi = ni_ins_mi(ni, &ni->mi_tree, m->rno, &m->node); + if (*mi != m) + mi_put(m); + return true; }