jbd2: Fix memory leak in journal_init_common()

There is a memory leak reported by kmemleak:

  unreferenced object 0xff11000105903b80 (size 64):
    comm "mount", pid 3382, jiffies 4295032021 (age 27.826s)
    hex dump (first 32 bytes):
      04 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00  ................
      ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00  ................
    backtrace:
      [<ffffffffae86ac40>] __kmalloc_node+0x50/0x160
      [<ffffffffaf2486d8>] crypto_alloc_tfmmem.isra.0+0x38/0x110
      [<ffffffffaf2498e5>] crypto_create_tfm_node+0x85/0x2f0
      [<ffffffffaf24a92c>] crypto_alloc_tfm_node+0xfc/0x210
      [<ffffffffaedde777>] journal_init_common+0x727/0x1ad0
      [<ffffffffaede1715>] jbd2_journal_init_inode+0x2b5/0x500
      [<ffffffffaed786b5>] ext4_load_and_init_journal+0x255/0x2440
      [<ffffffffaed8b423>] ext4_fill_super+0x8823/0xa330
      ...

The root cause was traced to an error handing path in journal_init_common()
when malloc memory failed in register_shrinker(). The checksum driver is
used to reference to checksum algorithm via cryptoapi and the user should
release the memory when the driver is no longer needed or the journal
initialization failed.

Fix it by calling crypto_free_shash() on the "err_cleanup" error handing
path in journal_init_common().

Fixes: c30713084ba5 ("jbd2: move load_superblock() into journal_init_common()")
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230911025138.983101-1-lizetao1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 15e33c26c6cd7011fb137b4d426c224ddf85c159..3ffda557dbdf932e0ac846444e50c7a816eed03a 100644 (file)
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1604,6 +1604,8 @@ static journal_t *journal_init_common(struct block_device *bdev,
 
 err_cleanup:
        percpu_counter_destroy(&journal->j_checkpoint_jh_count);
+       if (journal->j_chksum_driver)
+               crypto_free_shash(journal->j_chksum_driver);
        kfree(journal->j_wbuf);
        jbd2_journal_destroy_revoke(journal);
        journal_fail_superblock(journal);