From: Liequan Che cheliequan@inspur.com

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 cheliequan@inspur.com Cc: stable@vger.kernel.org Cc: Zheng Wang zyytlz.wz@163.com Reviewed-by: Mingzhe Zou mingzhe.zou@easystack.cn Signed-off-by: Coly Li colyli@suse.de --- 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);

/*