Re: [PATCH] fuse: check whether fuse_request_alloc returns NULL in fuse_simple_request

From: Zhiqiang Liu
Date: Wed Nov 04 2020 - 20:33:47 EST


ping ...

On 2020/10/22 21:13, Zhiqiang Liu wrote:
>
> In fuse_simple_request func, we will call fuse_request_alloc func to alloc
> one request from fuse_req_cachep when args->force is true. However, the
> return value of fuse_request_alloc func is not checked whether it is NULL.
> If allocating request fails, access-NULL-pointer problem will occur.
>
> Here, we check the return value of fuse_request_alloc func.
>
> Fixes: 7213394c4e18 ("fuse: simplify request allocation")
> Signed-off-by: Zhiqiang Liu <liuzhiqiang26@xxxxxxxxxx>
> Signed-off-by: Haotian Li <lihaotian9@xxxxxxxxxx>
> ---
> fs/fuse/dev.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> index 02b3c36b3676..f7dd33ae8e31 100644
> --- a/fs/fuse/dev.c
> +++ b/fs/fuse/dev.c
> @@ -481,6 +481,8 @@ ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)
> if (args->force) {
> atomic_inc(&fc->num_waiting);
> req = fuse_request_alloc(GFP_KERNEL | __GFP_NOFAIL);
> + if (!req)
> + return -ENOMEM;
>
> if (!args->nocreds)
> fuse_force_creds(fc, req);
>