bcache: memset on stack variables in bch_btree_check() and bch_sectors_dirty_init()

mainline inclusion
from v5.19-rc1
commit 7d6b902e
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I59A5L?from=project-issue
CVE: N/A

---------------------------------------

The local variables check_state (in bch_btree_check()) and state (in
bch_sectors_dirty_init()) should be fully filled by 0, because before
allocating them on stack, they were dynamically allocated by kzalloc().
Signed-off-by: NColy Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20220527152818.27545-2-colyli@suse.deSigned-off-by: NJens Axboe <axboe@kernel.dk>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/md/bcache/btree.c

@@ -2017,6 +2017,7 @@ int bch_btree_check(struct cache_set *c)
 	if (c->root->level == 0)
 		return 0;
 
+	memset(&check_state, 0, sizeof(struct btree_check_state));
 	check_state.c = c;
 	check_state.total_threads = bch_btree_chkthread_nr();
 	check_state.key_idx = 0;

drivers/md/bcache/writeback.c

@@ -950,6 +950,7 @@ void bch_sectors_dirty_init(struct bcache_device *d)
 		return;
 	}
 
+	memset(&state, 0, sizeof(struct bch_dirty_init_state));
 	state.c = c;
 	state.d = d;
 	state.total_threads = bch_btre_dirty_init_thread_nr();