This is a note to let you know that I've just added the patch titled
ext4: fix possible use-after-free with AIO
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ext4-fix-possible-use-after-free-with-aio.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3e411534ea3be89a7d0ddf4e62e5c5b79d80556a Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@xxxxxxx>
Date: Tue, 29 Jan 2013 22:48:17 -0500
Subject: ext4: fix possible use-after-free with AIO
From: Jan Kara <jack@xxxxxxx>
commit 091e26dfc156aeb3b73bc5c5f277e433ad39331c upstream.
Running AIO is pinning inode in memory using file reference. Once AIO
is completed using aio_complete(), file reference is put and inode can
be freed from memory. So we have to be sure that calling aio_complete()
is the last thing we do with the inode.
Reviewed-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
Acked-by: Jeff Moyer <jmoyer@xxxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Cc: Rui Xiang <rui.xiang@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/inode.c | 2 +-
fs/ext4/page-io.c | 9 ++++-----
2 files changed, 5 insertions(+), 6 deletions(-)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2800,9 +2800,9 @@ static void ext4_end_io_dio(struct kiocb
if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
ext4_free_io_end(io_end);
out:
+ inode_dio_done(inode);
if (is_async)
aio_complete(iocb, ret, 0);
- inode_dio_done(inode);
return;
}
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -107,14 +107,13 @@ int ext4_end_io_nolock(ext4_io_end_t *io
inode->i_ino, offset, size, ret);
}
- if (io->iocb)
- aio_complete(io->iocb, io->result, 0);
-
- if (io->flag & EXT4_IO_END_DIRECT)
- inode_dio_done(inode);
/* Wake up anyone waiting on unwritten extent conversion */
if (atomic_dec_and_test(&EXT4_I(inode)->i_aiodio_unwritten))
wake_up_all(ext4_ioend_wq(io->inode));
+ if (io->flag & EXT4_IO_END_DIRECT)
+ inode_dio_done(inode);
+ if (io->iocb)
+ aio_complete(io->iocb, io->result, 0);
return ret;
}
Patches currently in stable-queue which might be from jack@xxxxxxx are
queue-3.4/ext4-fix-possible-use-after-free-with-aio.patch
queue-3.4/quota-fix-race-between-dqput-and-dquot_scan_active.patch
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