From b2e382ae12a63560fca35050498e19e760adf8c0 Mon Sep 17 00:00:00 2001 From: Liequan Che Date: Mon, 2 Dec 2024 19:56:38 +0800 Subject: [PATCH] bcache: revert replacing IS_ERR_OR_NULL with IS_ERR again Commit 028ddcac477b ("bcache: Remove unnecessary NULL point check in node allocations") leads a NULL pointer deference in cache_set_flush(). 1721 if (!IS_ERR_OR_NULL(c->root)) 1722 list_add(&c->root->list, &c->btree_cache); >From the above code in cache_set_flush(), if previous registration code fails before allocating c->root, it is possible c->root is NULL as what it is initialized. __bch_btree_node_alloc() never returns NULL but c->root is possible to be NULL at above line 1721. This patch replaces IS_ERR() by IS_ERR_OR_NULL() to fix this. Fixes: 028ddcac477b ("bcache: Remove unnecessary NULL point check in node allocations") Signed-off-by: Liequan Che Cc: stable@vger.kernel.org Cc: Zheng Wang Reviewed-by: Mingzhe Zou Signed-off-by: Coly Li Link: https://lore.kernel.org/r/20241202115638.28957-1-colyli@suse.de Signed-off-by: Jens Axboe --- drivers/md/bcache/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index e7abfdd77c3b..e42f1400cea9 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1718,7 +1718,7 @@ static CLOSURE_CALLBACK(cache_set_flush) if (!IS_ERR_OR_NULL(c->gc_thread)) kthread_stop(c->gc_thread); - if (!IS_ERR(c->root)) + if (!IS_ERR_OR_NULL(c->root)) list_add(&c->root->list, &c->btree_cache); /*