@@ -238,7 +238,7 @@ write_out_data:
spin_lock(&journal->j_list_lock);
}
/* Someone already cleaned up the buffer? */
- if (!buffer_jbd(bh)
+ if (!buffer_jbd(bh) || bh2jh(bh) != jh
|| jh->b_transaction != commit_transaction
|| jh->b_jlist != BJ_SyncData) {
jbd_unlock_bh_state(bh);
@@ -463,7 +463,9 @@ void journal_commit_transaction(journal_
spin_lock(&journal->j_list_lock);
continue;
}
- if (buffer_jbd(bh) && jh->b_jlist == BJ_Locked) {
+ if (buffer_jbd(bh) && bh2jh(bh) == jh &&
+ jh->b_transaction == commit_transaction &&
+ jh->b_jlist == BJ_Locked) {
__journal_unfile_buffer(jh);
jbd_unlock_bh_state(bh);
journal_remove_journal_head(bh);
This is a note to let you know that we have just queued up the patch titled Subject: jbd: fix race in buffer processing in commit code to the 2.6.27-stable tree. Its filename is jbd-fix-race-in-buffer-processing-in-commit-code.patch A git repo of this tree can be found at http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary From a61d90d75d0f9e86432c45b496b4b0fbf0fd03dc Mon Sep 17 00:00:00 2001 From: Jan Kara <jack@suse.cz> Date: Tue, 9 Jun 2009 16:26:26 -0700 Subject: jbd: fix race in buffer processing in commit code From: Jan Kara <jack@suse.cz> commit a61d90d75d0f9e86432c45b496b4b0fbf0fd03dc upstream. In commit code, we scan buffers attached to a transaction. During this scan, we sometimes have to drop j_list_lock and then we recheck whether the journal buffer head didn't get freed by journal_try_to_free_buffers(). But checking for buffer_jbd(bh) isn't enough because a new journal head could get attached to our buffer head. So add a check whether the journal head remained the same and whether it's still at the same transaction and list. This is a nasty bug and can cause problems like memory corruption (use after free) or trigger various assertions in JBD code (observed). Signed-off-by: Jan Kara <jack@suse.cz> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- fs/jbd/commit.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) Patches currently in stable-queue which might be from jack@suse.cz are queue-2.6.27/jbd-fix-race-in-buffer-processing-in-commit-code.patch -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html