diff options
| author | Tejun Heo <tj@kernel.org> | 2011-11-24 19:22:24 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-12-09 08:54:18 -0800 |
| commit | 01da30a885baa667801facc2a54c80346ab6c414 (patch) | |
| tree | 9c56a582bdb26fb0ee11f8eac4f56d4f6e6bfbab | |
| parent | 453fdf5561cc042b7e127af6a62138969726f539 (diff) | |
ext4: fix racy use-after-free in ext4_end_io_dio()
commit 4c81f045c0bd2cbb78cc6446a4cd98038fe11a2e upstream.
ext4_end_io_dio() queues io_end->work and then clears iocb->private;
however, io_end->work calls aio_complete() which frees the iocb
object. If that slab object gets reallocated, then ext4_end_io_dio()
can end up clearing someone else's iocb->private, this use-after-free
can cause a leak of a struct ext4_io_end_t structure.
Detected and tested with slab poisoning.
[ Note: Can also reproduce using 12 fio's against 12 file systems with the
following configuration file:
[global]
direct=1
ioengine=libaio
iodepth=1
bs=4k
ba=4k
size=128m
[create]
filename=${TESTDIR}
rw=write
-- tytso ]
Google-Bug-Id: 5354697
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: Kent Overstreet <koverstreet@google.com>
Tested-by: Kent Overstreet <koverstreet@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | fs/ext4/inode.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 89c47f4ee005..b644b9c164a7 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2656,8 +2656,8 @@ out: spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); /* queue the work to convert unwritten extents to written */ - queue_work(wq, &io_end->work); iocb->private = NULL; + queue_work(wq, &io_end->work); /* XXX: probably should move into the real I/O completion handler */ inode_dio_done(inode); |