Re: [PATCH] fuse: fix kernel NULL pointer dereference in fuse_uring_add_to_pq()

[Li Wang <liwang@kylinos.cn>]

Hi Joanne,

On 23/04/2026 03:18, Joanne Koong wrote:

> 
> Thanks for testing/reporting this! This lgtm but afaict, the patches
> in that patchset aren't finalized yet so imo it'd be cleaner if this
> gets folded into the original patch [1] instead of being its own
> separate commit.
> 
> I think using fuse_pqueue_alloc() ends up being a tad bit cleaner
> 

Thanks for the feedback. I'm fine with either way (fold or split), 
and I will follow your suggestions and send out a v2.

Thanks,
Li

> diff --git a/fs/fuse/dev_uring.c b/fs/fuse/dev_uring.c
> index 5abf447e9710..e467b23e6895 100644
> --- a/fs/fuse/dev_uring.c
> +++ b/fs/fuse/dev_uring.c
> @@ -277,7 +277,7 @@ static struct fuse_ring_queue
> *fuse_uring_create_queue(struct fuse_ring *ring,
>         queue = kzalloc_obj(*queue, GFP_KERNEL_ACCOUNT);
>         if (!queue)
>                 return NULL;
> -       pq = kzalloc_objs(struct list_head, FUSE_PQ_HASH_SIZE);
> +       pq = fuse_pqueue_alloc();
>         if (!pq) {
>                 kfree(queue);
>                 return NULL;
> @@ -295,8 +295,8 @@ static struct fuse_ring_queue
> *fuse_uring_create_queue(struct fuse_ring *ring,
>         INIT_LIST_HEAD(&queue->fuse_req_bg_queue);
>         INIT_LIST_HEAD(&queue->ent_released);
> 
> -       queue->fpq.processing = pq;
>         fuse_pqueue_init(&queue->fpq);
> +       queue->fpq.processing = pq;
> 
> after exporting fuse_pqueue_alloc() into fuse_dev_i.h
> 
> Thanks,
> Joanne
> 
> [1] https://lore.kernel.org/fuse-devel/20260416091658.462783-32-mszeredi@redhat.com/