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| author | Jan Kara <jack@suse.cz> | 2013-03-11 21:24:56 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-28 23:12:15 +0400 |
| commit | ac4f52e0fff3a2b5523655250cc2e7d77ba8c09b (patch) | |
| tree | 94f566e310b0f8eefdbf2237b414b0f03f243760 /fs/jbd2/transaction.c | |
| parent | 056f8c8c85d53311530fd1940a68a390cc615bde (diff) | |
| download | linux-ac4f52e0fff3a2b5523655250cc2e7d77ba8c09b.tar.xz | |
jbd2: fix use after free in jbd2_journal_dirty_metadata()
commit ad56edad089b56300fd13bb9eeb7d0424d978239 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 de8b4cb7c31e..6075ac03b6d9 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -1047,9 +1047,12 @@ 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, @@ -1101,17 +1104,18 @@ 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); @@ -1202,6 +1206,7 @@ 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 */ |