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From:   Ye Bin <yebin10@huawei.com>
To:     <tytso@mit.edu>, <adilger.kernel@dilger.ca>,
        <linux-ext4@vger.kernel.org>
CC:     <linux-kernel@vger.kernel.org>, <jack@suse.cz>,
        Ye Bin <yebin10@huawei.com>
Subject: [PATCH -next v2 1/3] ext4: fix potential memory leak in ext4_fc_record_modified_inode()
Date:   Wed, 21 Sep 2022 14:40:38 +0800
Message-ID: <20220921064040.3693255-2-yebin10@huawei.com>
In-Reply-To: <20220921064040.3693255-1-yebin10@huawei.com>
References: <20220921064040.3693255-1-yebin10@huawei.com>
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Precedence: bulk

As krealloc may return NULL, in this case 'state->fc_modified_inodes'
may not be freed by krealloc, but 'state->fc_modified_inodes' already
set NULL. Then will lead to 'state->fc_modified_inodes' memory leak.

Signed-off-by: Ye Bin <yebin10@huawei.com>
---
 fs/ext4/fast_commit.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 88575f3d0dc5..29a22ee0adb8 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -1486,13 +1486,15 @@ static int ext4_fc_record_modified_inode(struct super_block *sb, int ino)
 		if (state->fc_modified_inodes[i] == ino)
 			return 0;
 	if (state->fc_modified_inodes_used == state->fc_modified_inodes_size) {
-		state->fc_modified_inodes = krealloc(
-				state->fc_modified_inodes,
+		int *fc_modified_inodes;
+
+		fc_modified_inodes = krealloc(state->fc_modified_inodes,
 				sizeof(int) * (state->fc_modified_inodes_size +
 				EXT4_FC_REPLAY_REALLOC_INCREMENT),
 				GFP_KERNEL);
-		if (!state->fc_modified_inodes)
+		if (!fc_modified_inodes)
 			return -ENOMEM;
+		state->fc_modified_inodes = fc_modified_inodes;
 		state->fc_modified_inodes_size +=
 			EXT4_FC_REPLAY_REALLOC_INCREMENT;
 	}
-- 
2.31.1