From: Peng Fan Date: Tue, 28 Oct 2025 14:23:32 +0000 (+0800) Subject: PM: EM: Add to em_pd_list only when no failure X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=65df3a9629c10d70593bc90b2ca6b235b7a24909;p=thirdparty%2Flinux.git PM: EM: Add to em_pd_list only when no failure When em_create_perf_table() returns failure, pd is freed, there dev->em_pd is not valid. Then accessing dev->em_pd->node will trigger kernel panic in em_dev_register_pd_no_update(). So return early if 'ret' is non-zero. Kernel dump: cpu cpu0: EM: invalid power: 0 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 Mem abort info: pc : em_dev_register_pd_no_update+0xb4/0x79c lr : em_dev_register_pd_no_update+0x9c/0x79c Call trace: em_dev_register_pd_no_update+0xb4/0x79c (P) em_dev_register_perf_domain+0x18/0x58 scmi_cpufreq_register_em+0x84/0xb8 cpufreq_online+0x48c/0xb74 cpufreq_add_dev+0x80/0x98 subsys_interface_register+0x100/0x11c cpufreq_register_driver+0x158/0x278 scmi_cpufreq_probe+0x1f8/0x2e0 scmi_dev_probe+0x28/0x3c really_probe+0xbc/0x29c __driver_probe_device+0x78/0x12c driver_probe_device+0x3c/0x15c __device_attach_driver+0xb8/0x134 bus_for_each_drv+0x84/0xe4 Fixes: cbe5aeedecc7 ("PM: EM: Assign a unique ID when creating a performance domain") Signed-off-by: Peng Fan Reviewed-by: Changwoo Min Reviewed-by: Lukasz Luba Link: https://patch.msgid.link/20251028-fix-energy-v1-1-ab854fd6a97c@nxp.com Signed-off-by: Rafael J. Wysocki --- diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index e669d5057fca..11af9f64aa82 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -693,13 +693,16 @@ int em_dev_register_pd_no_update(struct device *dev, unsigned int nr_states, unlock: mutex_unlock(&em_pd_mutex); + if (ret) + return ret; mutex_lock(&em_pd_list_mutex); list_add_tail(&dev->em_pd->node, &em_pd_list); mutex_unlock(&em_pd_list_mutex); em_notify_pd_created(dev->em_pd); - return ret; + + return 0; } EXPORT_SYMBOL_GPL(em_dev_register_pd_no_update);