6.18-stable review patch. If anyone has any objections, please let me know.
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From: Liang Jie liangjie@lixiang.com
[ Upstream commit b0101ccb5b4641885f30fecc352ef891ed06e083 ]
Smatch reported:
kernel/sched/ext.c:5332 scx_alloc_and_add_sched() warn: passing zero to 'ERR_PTR'
In scx_alloc_and_add_sched(), the alloc_percpu() failure path jumps to err_free_gdsqs without initializing @ret. That can lead to returning ERR_PTR(0), which violates the ERR_PTR() convention and confuses callers.
Set @ret to -ENOMEM before jumping to the error path when alloc_percpu() fails.
Reported-by: kernel test robot lkp@intel.com Closes: https://lore.kernel.org/r/202512141601.yAXDAeA9-lkp@intel.com/ Reported-by: Dan Carpenter error27@gmail.com Fixes: c201ea1578d3 ("sched_ext: Move event_stats_cpu into scx_sched") Signed-off-by: Liang Jie liangjie@lixiang.com Reviewed-by: Emil Tsalapatis emil@etsalapatis.com Reviewed-by: Andrea Righi arighi@nvidia.com Signed-off-by: Tejun Heo tj@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/sched/ext.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 6139263afd59..31eda2a56920 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -4508,8 +4508,10 @@ static struct scx_sched *scx_alloc_and_add_sched(struct sched_ext_ops *ops) }
sch->pcpu = alloc_percpu(struct scx_sched_pcpu); - if (!sch->pcpu) + if (!sch->pcpu) { + ret = -ENOMEM; goto err_free_gdsqs; + }
sch->helper = kthread_run_worker(0, "sched_ext_helper"); if (IS_ERR(sch->helper)) {