Commit e382e130 authored Oct 10, 2016 by Nikolay Borisov Committed by Greg Kroah-Hartman Oct 28, 2016

ceph: fix error handling in ceph_read_iter



commit 0d7718f666be181fda1ba2d08f137d87c1419347 upstream.

In case __ceph_do_getattr returns an error and the retry_op in
ceph_read_iter is not READ_INLINE, then it's possible to invoke
__free_page on a page which is NULL, this naturally leads to a crash.
This can happen when, for example, a process waiting on a MDS reply
receives sigterm.

Fix this by explicitly checking whether the page is set or not.

Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Reviewed-by: Yan, Zheng <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 08cd19c6

fs/ceph/file.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -929,6 +929,7 @@ again:
		statret = __ceph_do_getattr(inode, page,
		CEPH_STAT_CAP_INLINE_DATA, !!page);
		if (statret < 0) {
		if (page)
		__free_page(page);
		if (statret == -ENODATA) {
		BUG_ON(retry_op != READ_INLINE);