From e7385c868ee038d6a0cb0e85c22d2741e7910fd5 Mon Sep 17 00:00:00 2001 From: Ye Bin Date: Wed, 14 Sep 2022 18:08:11 +0800 Subject: [PATCH] jbd2: fix potential buffer head reference count leak MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit e0d5fc7a6d80ac2406c7dfc6bb625201d0250a8a upstream. 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: Ye Bin Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20220914100812.1414768-2-yebin10@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/jbd2/journal.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 1f8493e..a6efcf5 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -926,8 +926,14 @@ 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; -- 2.7.4