ext4: fix potential memory leak in ext4_fc_record_modified_inode()

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.

Cc: stable@kernel.org
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220921064040.3693255-2-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 9217a588afd133e85ad906fd4de73a9938b1924a..9555ab816d7d3426a0af8e6af8b4ebce0e9f04a9 100644 (file)
--- 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;
        }