1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <linux/compat.h> 4 #include <linux/errno.h> 5 #include <linux/prctl.h> 6 #include <linux/random.h> 7 #include <linux/sched.h> 8 #include <asm/cpufeature.h> 9 #include <asm/pointer_auth.h> 10 11 int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg) 12 { 13 struct ptrauth_keys_user *keys = &tsk->thread.keys_user; 14 unsigned long addr_key_mask = PR_PAC_APIAKEY | PR_PAC_APIBKEY | 15 PR_PAC_APDAKEY | PR_PAC_APDBKEY; 16 unsigned long key_mask = addr_key_mask | PR_PAC_APGAKEY; 17 18 if (!system_supports_address_auth() && !system_supports_generic_auth()) 19 return -EINVAL; 20 21 if (is_compat_thread(task_thread_info(tsk))) 22 return -EINVAL; 23 24 if (!arg) { 25 ptrauth_keys_init_user(keys); 26 return 0; 27 } 28 29 if (arg & ~key_mask) 30 return -EINVAL; 31 32 if (((arg & addr_key_mask) && !system_supports_address_auth()) || 33 ((arg & PR_PAC_APGAKEY) && !system_supports_generic_auth())) 34 return -EINVAL; 35 36 if (arg & PR_PAC_APIAKEY) 37 get_random_bytes(&keys->apia, sizeof(keys->apia)); 38 if (arg & PR_PAC_APIBKEY) 39 get_random_bytes(&keys->apib, sizeof(keys->apib)); 40 if (arg & PR_PAC_APDAKEY) 41 get_random_bytes(&keys->apda, sizeof(keys->apda)); 42 if (arg & PR_PAC_APDBKEY) 43 get_random_bytes(&keys->apdb, sizeof(keys->apdb)); 44 if (arg & PR_PAC_APGAKEY) 45 get_random_bytes(&keys->apga, sizeof(keys->apga)); 46 47 return 0; 48 } 49