From 336b87081835f5fcc3fdd4e2c8823b61c50a1b2e Mon Sep 17 00:00:00 2001 From: Ming Li Date: Thu, 15 Apr 2021 13:09:18 +0800 Subject: [PATCH] check head in page_chain_del for every loop there will be crash when we get a NULL head in loop. Signed-off-by: Ming Li --- drbd/drbd_receiver.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drbd/drbd_receiver.c b/drbd/drbd_receiver.c index f127a235..28fb2e06 100644 --- a/drbd/drbd_receiver.c +++ b/drbd/drbd_receiver.c @@ -280,12 +280,12 @@ static struct page *page_chain_del(struct page **head, int count) BUG_ON(!head); page = READ_ONCE(*head); - if (!page) - return NULL; do { n = count; rv_head = page; + if (!page) + return NULL; while (true) { tmp = page_chain_next(page); if (--n == 0) -- 2.24.3 (Apple Git-128)