From 76c488e8a0e2783c6d8753cb7354a420593e8c30 Mon Sep 17 00:00:00 2001 From: Zhihao Cheng Date: Fri, 18 Nov 2022 17:02:36 +0800 Subject: [PATCH] ubifs: dirty_cow_znode: Fix memleak in error handling path [ Upstream commit 122deabfe1428bffe95e2bf364ff8a5059bdf089 ] Following process will cause a memleak for copied up znode: dirty_cow_znode zn = copy_znode(c, znode); err = insert_old_idx(c, zbr->lnum, zbr->offs); if (unlikely(err)) return ERR_PTR(err); // No one refers to zn. Fix it by adding copied znode back to tnc, then it will be freed by ubifs_destroy_tnc_subtree() while closing tnc. Fetch a reproducer in [Link]. Link: https://bugzilla.kernel.org/show_bug.cgi?id=216705 Fixes: 1e51764a3c2a ("UBIFS: add new flash file system") Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin --- fs/ubifs/tnc.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c index 2df56bb..2469f72 100644 --- a/fs/ubifs/tnc.c +++ b/fs/ubifs/tnc.c @@ -267,11 +267,18 @@ static struct ubifs_znode *dirty_cow_znode(struct ubifs_info *c, if (zbr->len) { err = insert_old_idx(c, zbr->lnum, zbr->offs); if (unlikely(err)) - return ERR_PTR(err); + /* + * Obsolete znodes will be freed by tnc_destroy_cnext() + * or free_obsolete_znodes(), copied up znodes should + * be added back to tnc and freed by + * ubifs_destroy_tnc_subtree(). + */ + goto out; err = add_idx_dirt(c, zbr->lnum, zbr->len); } else err = 0; +out: zbr->znode = zn; zbr->lnum = 0; zbr->offs = 0; -- 2.7.4