From d3f1ec54e3453e54463fcff5be36ec8ebc06de53 Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Mon, 10 Oct 2016 15:38:18 +0300 Subject: [PATCH] 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 Reviewed-by: Yan, Zheng Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman --- fs/ceph/file.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/ceph/file.c b/fs/ceph/file.c index 0f5375d8e0305..eede975e85c0e 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -1272,7 +1272,8 @@ again: statret = __ceph_do_getattr(inode, page, CEPH_STAT_CAP_INLINE_DATA, !!page); if (statret < 0) { - __free_page(page); + if (page) + __free_page(page); if (statret == -ENODATA) { BUG_ON(retry_op != READ_INLINE); goto again; -- 2.47.2