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authorJan Kara <jack@suse.cz>2013-01-29 22:48:17 -0500
committerTheodore Ts'o <tytso@mit.edu>2013-01-29 22:48:17 -0500
commit091e26dfc156aeb3b73bc5c5f277e433ad39331c (patch)
tree03a95cea66597c0b7289ea6fbdc13785a5e21919
parentb1deefc99e668348f7c785c6ece5f6ff4c6d8b5c (diff)
ext4: fix possible use-after-free with AIO
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. CC: stable@vger.kernel.org Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
-rw-r--r--fs/ext4/inode.c2
-rw-r--r--fs/ext4/page-io.c9
2 files changed, 5 insertions, 6 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 86bf43d6dfcd..07d9defeaf8c 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2850,9 +2850,9 @@ static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
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;
}
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 5d8c66948e1b..809b31003ecc 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -102,14 +102,13 @@ static int ext4_end_io(ext4_io_end_t *io)
"(inode %lu, offset %llu, size %zd, error %d)",
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_unwritten))
wake_up_all(ext4_ioend_wq(inode));
+ if (io->flag & EXT4_IO_END_DIRECT)
+ inode_dio_done(inode);
+ if (io->iocb)
+ aio_complete(io->iocb, io->result, 0);
return ret;
}