From 94a4acfec14615e971eb2c9e1fa6c992c85ff6c6 Mon Sep 17 00:00:00 2001 From: Chen Ridong Date: Fri, 22 Aug 2025 07:07:15 +0000 Subject: [PATCH] cgroup/psi: Set of->priv to NULL upon file release Setting of->priv to NULL when the file is released enables earlier bug detection. This allows potential bugs to manifest as NULL pointer dereferences rather than use-after-free errors[1], which are generally more difficult to diagnose. [1] https://lore.kernel.org/cgroups/38ef3ff9-b380-44f0-9315-8b3714b0948d@huaweicloud.com/T/#m8a3b3f88f0ff3da5925d342e90043394f8b2091b Signed-off-by: Chen Ridong Signed-off-by: Tejun Heo --- kernel/cgroup/cgroup.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 79b1d79f86a34..77d02f87f3f12 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -4182,6 +4182,7 @@ static void cgroup_file_release(struct kernfs_open_file *of) cft->release(of); put_cgroup_ns(ctx->ns); kfree(ctx); + of->priv = NULL; } static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf, -- 2.47.3