From: Yang Yingliang <yangyingliang@huawei.com>
Date: Mon, 10 May 2021 11:10:51 +0000 (+0800)
Subject: ext4: return error code when ext4_fill_flex_info() fails
X-Git-Tag: v5.4.132~323
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f01fa29e8ea03659cc0bc27b9d71068da0914337;p=users%2Fdwmw2%2Flinux.git

ext4: return error code when ext4_fill_flex_info() fails

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>
---

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a64ed9c45ee23..ce8372ceaa43e 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4618,6 +4618,7 @@ no_journal:
 			ext4_msg(sb, KERN_ERR,
 			       "unable to initialize "
 			       "flex_bg meta info!");
+			ret = -ENOMEM;
 			goto failed_mount6;
 		}