The commit 4982223e51e8 module: set nx before marking module MODULE_STATE_COMING. introduced a regression: if a module fails to parse its arguments or if mod_sysfs_setup fails, then the module's memory will be freed while still read-only. Anything that reuses that memory will crash as soon as it tries to write to it.
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| @@ -3304,6 +3304,11 @@ static int load_module(struct load_info *info, const char __user *uargs, · 3303 unmodified lines | ||
| 3304 | 3304 | mutex_lock(&module_mutex); |
| 3305 | 3305 | module_bug_cleanup(mod); |
| 3306 | 3306 | mutex_unlock(&module_mutex); |
| 3307 | + | |
| 3308 | + /* we can't deallocate the module until we clear memory protection */ | |
| 3309 | + unset_module_init_ro_nx(mod); | |
| 3310 | + unset_module_core_ro_nx(mod); | |
| 3311 | + | |
| 3307 | 3312 | ddebug_cleanup: |
| 3308 | 3313 | dynamic_debug_remove(info->debug); |
| 3309 | 3314 | synchronize_sched(); |