From: Zhihao Cheng chengzhihao1@huawei.com
[ 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 chengzhihao1@huawei.com Signed-off-by: Richard Weinberger richard@nod.at Signed-off-by: Sasha Levin sashal@kernel.org --- 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 20b70e178c4fa..6c4af1cfce346 100644 --- a/fs/ubifs/tnc.c +++ b/fs/ubifs/tnc.c @@ -279,11 +279,18 @@ 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;