diff options
| author | Jan Kara <jack@suse.cz> | 2013-03-11 18:24:56 +0100 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2013-03-11 18:24:56 +0100 |
| commit | ad56edad089b56300fd13bb9eeb7d0424d978239 (patch) | |
| tree | bb350333433690e5a7ce3f2481c055c78ac5fef7 /fs/jbd2/transaction.c | |
| parent | ext4: reserve metadata block for every delayed write (diff) | |
| download | linux-ad56edad089b56300fd13bb9eeb7d0424d978239.tar.xz linux-ad56edad089b56300fd13bb9eeb7d0424d978239.zip | |
jbd2: fix use after free in jbd2_journal_dirty_metadata()
jbd2_journal_dirty_metadata() didn't get a reference to journal_head it
was working with. This is OK in most of the cases since the journal head
should be attached to a transaction but in rare occasions when we are
journalling data, __ext4_journalled_writepage() can race with
jbd2_journal_invalidatepage() stripping buffers from a page and thus
journal head can be freed under hands of jbd2_journal_dirty_metadata().
Fix the problem by getting own journal head reference in
jbd2_journal_dirty_metadata() (and also in jbd2_journal_set_triggers()
which can possibly have the same issue).
Reported-by: Zheng Liu <gnehzuil.liu@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
Diffstat (limited to 'fs/jbd2/transaction.c')
| -rw-r--r-- | fs/jbd2/transaction.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index d6ee5aed56b1..325bc019ed88 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -1065,9 +1065,12 @@ out: void jbd2_journal_set_triggers(struct buffer_head *bh, struct jbd2_buffer_trigger_type *type) { - struct journal_head *jh = bh2jh(bh); + struct journal_head *jh = jbd2_journal_grab_journal_head(bh); + if (WARN_ON(!jh)) + return; jh->b_triggers = type; + jbd2_journal_put_journal_head(jh); } void jbd2_buffer_frozen_trigger(struct journal_head *jh, void *mapped_data, @@ -1119,17 +1122,18 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) { transaction_t *transaction = handle->h_transaction; journal_t *journal = transaction->t_journal; - struct journal_head *jh = bh2jh(bh); + struct journal_head *jh; int ret = 0; - jbd_debug(5, "journal_head %p\n", jh); - JBUFFER_TRACE(jh, "entry"); if (is_handle_aborted(handle)) goto out; - if (!buffer_jbd(bh)) { + jh = jbd2_journal_grab_journal_head(bh); + if (!jh) { ret = -EUCLEAN; goto out; } + jbd_debug(5, "journal_head %p\n", jh); + JBUFFER_TRACE(jh, "entry"); jbd_lock_bh_state(bh); @@ -1220,6 +1224,7 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) spin_unlock(&journal->j_list_lock); out_unlock_bh: jbd_unlock_bh_state(bh); + jbd2_journal_put_journal_head(jh); out: JBUFFER_TRACE(jh, "exit"); WARN_ON(ret); /* All errors are bugs, so dump the stack */ |