Commit e0d5fc7a authored by Ye Bin's avatar Ye Bin Committed by Theodore Ts'o
Browse files

jbd2: fix potential buffer head reference count leak 



As in 'jbd2_fc_wait_bufs' if buffer isn't uptodate, will return -EIO without
update 'journal->j_fc_off'. But 'jbd2_fc_release_bufs' will release buffer head
from ‘j_fc_off - 1’ if 'bh' is NULL will terminal release which will lead to
buffer head buffer head reference count leak.
To solve above issue, update 'journal->j_fc_off' before return -EIO.

Cc: stable@kernel.org
Signed-off-by: default avatarYe Bin <yebin10@huawei.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220914100812.1414768-2-yebin10@huawei.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 7177dd00

fs/jbd2/journal.c

+7 −1
Original line number Diff line number Diff line
@@ -925,9 +925,15 @@ int jbd2_fc_wait_bufs(journal_t *journal, int num_blks) 
		wait_on_buffer(bh);

		put_bh(bh);

		journal->j_fc_wbuf[i] = NULL;

		if (unlikely(!buffer_uptodate(bh)))

		/*

		 * Update j_fc_off so jbd2_fc_release_bufs can release remain

		 * buffer head.

		 */

		if (unlikely(!buffer_uptodate(bh))) {

			journal->j_fc_off = i;

			return -EIO;

		}

	}



	return 0;

}