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From:   Jan Kara <jack@suse.cz>
To:     Ted Tso <tytso@mit.edu>
Cc:     <linux-ext4@vger.kernel.org>, Lukas Czerner <lczerner@redhat.com>,
        Jan Kara <jack@suse.cz>
Subject: [PATCH 5/6] ext4: Handle add_system_zone() failure in ext4_setup_system_zone()
Date:   Mon, 27 Jul 2020 13:44:28 +0200
Message-Id: <20200727114429.1478-6-jack@suse.cz>
In-Reply-To: <20200727114429.1478-1-jack@suse.cz>
References: <20200727114429.1478-1-jack@suse.cz>
Sender: linux-ext4-owner@vger.kernel.org
Precedence: bulk

There's one place that fails to handle error from add_system_zone() call
and thus we can fail to protect superblock and group-descriptor blocks
properly in case of ENOMEM. Fix it.

Reported-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/block_validity.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
index 9c40214f31f9..2d008c1b58f2 100644
--- a/fs/ext4/block_validity.c
+++ b/fs/ext4/block_validity.c
@@ -235,10 +235,13 @@ int ext4_setup_system_zone(struct super_block *sb)
 	for (i=0; i < ngroups; i++) {
 		cond_resched();
 		if (ext4_bg_has_super(sb, i) &&
-		    ((i < 5) || ((i % flex_size) == 0)))
-			add_system_zone(system_blks,
+		    ((i < 5) || ((i % flex_size) == 0))) {
+			ret = add_system_zone(system_blks,
 					ext4_group_first_block_no(sb, i),
 					ext4_bg_num_gdb(sb, i) + 1, 0);
+			if (ret)
+				goto err;
+		}
 		gdp = ext4_get_group_desc(sb, i, NULL);
 		ret = add_system_zone(system_blks,
 				ext4_block_bitmap(sb, gdp), 1, 0);
-- 
2.16.4