diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 4ca3cb993da2..3de07258f57d 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -3995,7 +3995,7 @@ static int cgroup_cpu_pressure_show(struct seq_file *seq, void *v) static ssize_t pressure_write(struct kernfs_open_file *of, char *buf, size_t nbytes, enum psi_res res) { - struct cgroup_file_ctx *ctx = of->priv; + struct cgroup_file_ctx *ctx; struct psi_trigger *new; struct cgroup *cgrp; struct psi_group *psi; @@ -4004,12 +4004,18 @@ static ssize_t pressure_write(struct kernfs_open_file *of, char *buf, if (!cgrp) return -ENODEV; + ctx = of->priv; + if (!ctx) { + cgroup_kn_unlock(of->kn); + return -ENODEV; + } + cgroup_get(cgrp); - cgroup_kn_unlock(of->kn); /* Allow only one trigger per file descriptor */ if (ctx->psi.trigger) { cgroup_put(cgrp); + cgroup_kn_unlock(of->kn); return -EBUSY; } @@ -4017,12 +4023,14 @@ static ssize_t pressure_write(struct kernfs_open_file *of, char *buf, new = psi_trigger_create(psi, buf, res, of->file, of); if (IS_ERR(new)) { cgroup_put(cgrp); + cgroup_kn_unlock(of->kn); return PTR_ERR(new); } smp_store_release(&ctx->psi.trigger, new); cgroup_put(cgrp); + cgroup_kn_unlock(of->kn); return nbytes; }