Re: [PATCH] selftests: net: reuseport_bpf_numa: consider cpuless numa node

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Medium] Missing NULL check for cpumask allocation in is_cpuless_node()
- [Medium] Missing return value check for numa_node_to_cpus() leading to masked errors
--

--- Patch [1]: [PATCH] selftests: net: reuseport_bpf_numa: consider cpuless numa node ---
commit 806931cbf2ad9438843e4d30f69b4887e641f7d2
Author: Feng Tang <feng.tang@linux.alibaba.com>

selftests: net: reuseport_bpf_numa: consider cpuless numa node

This patch addresses a failure in the 'reuseport_bpf_numa' selftest on
platforms with CXL memory where one node is cpuless. It introduces an
is_cpuless_node() check to skip memory-only NUMA nodes during the binding
test.

> diff --git a/tools/testing/selftests/net/reuseport_bpf_numa.c b/tools/testing/selftests/net/reuseport_bpf_numa.c
> index 8ec52fc5ef41b..197dbfc475f65 100644
> --- a/tools/testing/selftests/net/reuseport_bpf_numa.c
> +++ b/tools/testing/selftests/net/reuseport_bpf_numa.c
[ ... ]
> @@ -104,13 +104,35 @@ static void attach_bpf(int fd)
>  	close(bpf_fd);
>  }
>  
> -static void send_from_node(int node_id, int family, int proto)
> +static inline bool is_cpuless_node(int node_id)
> +{
> +	struct bitmask *cpumask;
> +	bool ret = false;
> +
> +	cpumask = numa_allocate_cpumask();
> +
> +	numa_node_to_cpus(node_id, cpumask);

[Severity: Medium]
Will this crash if numa_allocate_cpumask() fails to allocate memory?

It looks like cpumask could be NULL here, which is passed directly to
numa_node_to_cpus() and numa_bitmask_weight() without validation.

> +	if (!numa_bitmask_weight(cpumask))
> +		ret = true;

[Severity: Medium]
What happens if numa_node_to_cpus() fails?

It can return a negative error value, leaving the cpumask unmodified with
zero bits set. Because the return value is not checked,
numa_bitmask_weight(cpumask) will evaluate to 0. Does this cause the function
to return true and silently skip testing on nodes where an error occurs,
rather than reporting the infrastructure issue?

> +
> +	numa_bitmask_free(cpumask);
> +	return ret;
> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260730113040.75718-1-feng.tang@linux.alibaba.com?part=1