aio: hold an extra file reference over AIO read/write operations

Otherwise we might dereference an already freed file and/or inode
when aio_complete is called before we return from the read_iter or
write_iter method.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/aio.c b/fs/aio.c
index 1157e13..0aa71d3 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1460,6 +1460,7 @@ rw_common:
                        return ret;
                }
 
+               get_file(file);
                if (rw == WRITE)
                        file_start_write(file);
 
@@ -1467,6 +1468,7 @@ rw_common:
 
                if (rw == WRITE)
                        file_end_write(file);
+               fput(file);
                kfree(iovec);
                break;