From bc9a10ed433fec684cee2332e9045f13aab6f36f Mon Sep 17 00:00:00 2001 From: Cathy Avery Date: Fri, 23 Oct 2015 18:12:46 +0800 Subject: [PATCH] xen-blkfront: check for null drvdata in blkback_changed (XenbusStateClosing) Orabug: 21935345 xen-blkfront will crash if the check to talk_to_blkback() in blkback_changed()(XenbusStateInitWait) returns an error. The driver data is freed and info is set to NULL. Later during the close process via talk_to_blkback's call to xenbus_dev_fatal() the null pointer is passed to and dereference in blkfront_closing. Signed-off-by: Cathy Avery Acked-by: Konrad Rzeszutek Wilk Signed-off-by: Joe Jin --- drivers/block/xen-blkfront.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 7a8a73f1fc04..d68b08ae4be1 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -1984,7 +1984,8 @@ static void blkback_changed(struct xenbus_device *dev, break; /* Missed the backend's Closing state -- fallthrough */ case XenbusStateClosing: - blkfront_closing(info); + if (info) + blkfront_closing(info); break; } } -- 2.49.0