diff options
| author | Jan Kara <jack@suse.cz> | 2009-02-10 11:15:34 -0500 |
|---|---|---|
| committer | Theodore Tso <tytso@mit.edu> | 2009-02-10 11:15:34 -0500 |
| commit | 7f5aa215088b817add9c71914b83650bdd49f8a9 (patch) | |
| tree | 9b811d1f0b41a2738fc68654ae605bf5d8cf2a72 /include/linux/jbd2.h | |
| parent | 9eddacf9e9c03578ef2c07c9534423e823d677f8 (diff) | |
| download | lwn-7f5aa215088b817add9c71914b83650bdd49f8a9.tar.gz lwn-7f5aa215088b817add9c71914b83650bdd49f8a9.zip | |
jbd2: Avoid possible NULL dereference in jbd2_journal_begin_ordered_truncate()
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: ocfs2-devel@oss.oracle.com
CC: mfasheh@suse.de
CC: Dan Carpenter <error27@gmail.com>
Diffstat (limited to 'include/linux/jbd2.h')
| -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 b28b37eb11c6..4d248b3f1323 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -1150,7 +1150,8 @@ 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); |