Re: [PATCH bpf] bpf: cpumap: Fix memory leak in cpu_map_update_elem

[Jesper Dangaard Brouer]

On 11/07/2023 13.58, Pu Lehui wrote:
> From: Pu Lehui <pulehui@xxxxxxxxxx>
>
> Syzkaller reported a memory leak as follows:
[...]>
> In the cpu_map_update_elem flow, when kthread_stop is called before
> calling the threadfn of rcpu->kthread, since the KTHREAD_SHOULD_STOP bit
> of kthread has been set by kthread_stop, the threadfn of rcpu->kthread
> will never be executed, and rcpu->refcnt will never be 0, which will
> lead to the allocated rcpu, rcpu->queue and rcpu->queue->queue cannot be
> released.
>
> Calling kthread_stop before executing kthread's threadfn will return
> -EINTR. We can complete the release of memory resources in this state.
>
> Fixes: 6710e1126934 ("bpf: introduce new bpf cpu map type BPF_MAP_TYPE_CPUMAP")
> Signed-off-by: Pu Lehui <pulehui@xxxxxxxxxx>

LGTM, thanks for fixing this.

Acked-by: Jesper Dangaard Brouer <hawk@xxxxxxxxxx>