From: Andrea Righi <arighi@nvidia.com> mainline inclusion from mainline-v6.14-rc7 commit 9360dfe4cbd62ff1eb8217b815964931523b75b3 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/ID7HLY Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commi... -------------------------------- If a BPF scheduler provides an invalid CPU (outside the nr_cpu_ids range) as prev_cpu to scx_bpf_select_cpu_dfl() it can cause a kernel crash. To prevent this, validate prev_cpu in scx_bpf_select_cpu_dfl() and trigger an scx error if an invalid CPU is specified. Fixes: f0e1a0643a59b ("sched_ext: Implement BPF extensible scheduler class") Cc: stable@vger.kernel.org # v6.12+ Signed-off-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Tejun Heo <tj@kernel.org> Conflicts: kernel/sched/ext.c kernel/sched/ext_idle.c [The function `scx_bpf_select_cpu_dfl` has been moved to ext_idle.c.] Signed-off-by: Zicheng Qu <quzicheng@huawei.com> Signed-off-by: cheliequan <cheliequan@inspur.com> Signed-off-by: Luo Gengkun <luogengkun2@huawei.com> --- kernel/sched/ext_idle.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/sched/ext_idle.c b/kernel/sched/ext_idle.c index 9824c5061a95..586d1b7ab3d6 100644 --- a/kernel/sched/ext_idle.c +++ b/kernel/sched/ext_idle.c @@ -563,6 +563,9 @@ static bool check_builtin_idle_enabled(void) __bpf_kfunc s32 scx_bpf_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, bool *is_idle) { + if (!ops_cpu_valid(prev_cpu, NULL)) + goto prev_cpu; + if (!check_builtin_idle_enabled()) goto prev_cpu; -- 2.34.1