UBI: fix oops in error path
This patch fixes an oops in the error path of 'ubi_attach_mtd_dev()'. If
anything after 'uif_init()' fails, we get an oops in 'cancel_pending()'. The
reason is that 'uif_close()' drops the last reference count for 'ubi->dev' and
whole 'struct ubi_device' is freed. And then
'ubi_wl_close()'->'cancel_pending()' tries to access the 'ubi' pointer and
problems begin.
Note, in 'ubi_detach_mtd_dev()' function we get a device reference to
work-around this issue. Do the same in the error path of
'ubi_attach_mtd_dev()'.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 6d0d483..6c3fb5a 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -1019,6 +1019,8 @@
out_debugfs:
ubi_debugfs_exit_dev(ubi);
out_uif:
+ get_device(&ubi->dev);
+ ubi_assert(ref);
uif_close(ubi);
out_detach:
ubi_wl_close(ubi);