From a6619810135b5365d1d4b83791a4e1f1464a0a41 Mon Sep 17 00:00:00 2001 From: Luis Chamberlain Date: Fri, 19 Jun 2020 20:47:27 +0000 Subject: [PATCH] loop: be paranoid on exit and prevent new additions / removals [ Upstream commit 200f93377220504c5e56754823e7adfea6037f1a ] Be pedantic on removal as well and hold the mutex. This should prevent uses of addition while we exit. Signed-off-by: Luis Chamberlain Reviewed-by: Ming Lei Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/loop.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 565e35e69f24..bddbbf5b3dda 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -2325,6 +2325,8 @@ static void __exit loop_exit(void) range = max_loop ? max_loop << part_shift : 1UL << MINORBITS; + mutex_lock(&loop_ctl_mutex); + idr_for_each(&loop_index_idr, &loop_exit_cb, NULL); idr_destroy(&loop_index_idr); @@ -2332,6 +2334,8 @@ static void __exit loop_exit(void) unregister_blkdev(LOOP_MAJOR, "loop"); misc_deregister(&loop_misc); + + mutex_unlock(&loop_ctl_mutex); } module_init(loop_init);