coresight: holding cscfg_csdev_lock while removing cscfg from csdev
In the Linux kernel, the following vulnerability has been resolved:
coresight: holding cscfg_csdev_lock while removing cscfg from csdev
There'll be possible race scenario for coresight config:
CPU0 CPU1 (perf enable) load module cscfg_load_config_sets() activate config. // sysfs (sys_active_cnt == 1) ... cscfg_csdev_enable_active_config() lock(csdev->cscfg_csdev_lock) deactivate config // sysfs (sys_activec_cnt == 0) cscfg_unload_config_sets() cscfg_remove_owned_csdev_configs() // here load config activate by CPU1 unlock(csdev->cscfg_csdev_lock)
iterating config_csdev_list could be raced with config_csdev_list's entry delete.
To resolve this race , hold csdev->cscfg_csdev_lock() while cscfg_remove_owned_csdev_configs()