diff options
| author | Jan Kara <jack@suse.cz> | 2009-02-24 16:13:18 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-03-16 17:53:04 -0700 |
| commit | fb05f46cabf4c96f5f8648c6a85d897ed57b1c94 (patch) | |
| tree | c556c02fd18094d39ab1982142a42b56534cced2 /include | |
| parent | 5328f9688e849b1c06d0433424a6c1387a9ade04 (diff) | |
jbd2: Avoid possible NULL dereference in jbd2_journal_begin_ordered_truncate()
(cherry picked from commit 7f5aa215088b817add9c71914b83650bdd49f8a9)
If we race with commit code setting i_transaction to NULL, we could
possibly dereference it. Proper locking requires the journal pointer
(to access journal->j_list_lock), which we don't have. So we have to
change the prototype of the function so that filesystem passes us the
journal pointer. Also add a more detailed comment about why the
function jbd2_journal_begin_ordered_truncate() does what it does and
how it should be used.
Thanks to Dan Carpenter <error27@gmail.com> for pointing to the
suspitious code.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Joel Becker <joel.becker@oracle.com>
CC: linux-ext4@vger.kernel.org
CC: mfasheh@suse.de
CC: Dan Carpenter <error27@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/jbd2.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 0e1bd70e0a4..df4137ece98 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -1075,7 +1075,8 @@ extern int jbd2_journal_clear_err (journal_t *); extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *); extern int jbd2_journal_force_commit(journal_t *); extern int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *inode); -extern int jbd2_journal_begin_ordered_truncate(struct jbd2_inode *inode, loff_t new_size); +extern int jbd2_journal_begin_ordered_truncate(journal_t *journal, + struct jbd2_inode *inode, loff_t new_size); extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode); extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode); |