From 8df5fc042c8e7c08dc438c8198b62407ee1e91a0 Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Mon, 7 Jul 2008 15:50:01 -0500 Subject: [SCSI] bsg: fix oops on remove If you do a modremove of any sas driver, you run into an oops on shutdown when the host is removed (coming from the host bsg device). The root cause seems to be that there's a use after free of the bsg_class_device: In bsg_kref_release_function, this is used (to do a put_device(bcg->parent) after bcg->release has been called. In sas (and possibly many other things) bcd->release frees the queue which contains the bsg_class_device, so we get a put_device on unreferenced memory. Fix this by taking a copy of the pointer to the parent before releasing bsg. Acked-by: FUJITA Tomonori Signed-off-by: James Bottomley --- block/bsg.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'block') diff --git a/block/bsg.c b/block/bsg.c index f0b7cd34321..54d617f7df3 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -709,11 +709,12 @@ static void bsg_kref_release_function(struct kref *kref) { struct bsg_class_device *bcd = container_of(kref, struct bsg_class_device, ref); + struct device *parent = bcd->parent; if (bcd->release) bcd->release(bcd->parent); - put_device(bcd->parent); + put_device(parent); } static int bsg_put_device(struct bsg_device *bd) -- cgit v1.2.3-70-g09d2