From: Yang Yingliang yangyingliang@huawei.com
commit 8f6840c4fd1e7bd715e403074fb161c1a04cda73 upstream.
After commit c89128a00838 ("ext4: handle errors on ext4_commit_super"), 'ret' may be set to 0 before calling ext4_fill_flex_info(), if ext4_fill_flex_info() fails ext4_mount() doesn't return error code, it makes 'root' is null which causes crash in legacy_get_tree().
Fixes: c89128a00838 ("ext4: handle errors on ext4_commit_super") Reported-by: Hulk Robot hulkci@huawei.com Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Yang Yingliang yangyingliang@huawei.com Link: https://lore.kernel.org/r/20210510111051.55650-1-yangyingliang@huawei.com Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/ext4/super.c | 1 + 1 file changed, 1 insertion(+)
--- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -5046,6 +5046,7 @@ no_journal: ext4_msg(sb, KERN_ERR, "unable to initialize " "flex_bg meta info!"); + ret = -ENOMEM; goto failed_mount6; }