> 2024年11月27日 11:01，liequan che <liequanche@xxxxxxxxx> 写道：
>
> 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. Also __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.
OK, this time the commit log makes a lot sense. It is clear to me.
>
> Fixes: 028ddcac477b ("bcache: Remove unnecessary NULL point check in
> node allocations")
> Signed-off-by: Liequan Che <cheliequan@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Zheng Wang <zyytlz.wz@xxxxxxx>
> Cc: Coly Li <colyli@xxxxxxx>
> ---
> 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);
>
> /*
> —
> 2.46.0
It is fine to me. I am in travel these days, and will handle this patch by end of this week.
Thanks for composing this patch.
Coly Li
