diff options
| -rw-r--r-- | arch/arm64/include/asm/pointer_auth.h | 3 | ||||
| -rw-r--r-- | arch/arm64/include/asm/processor.h | 4 | ||||
| -rw-r--r-- | arch/arm64/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/pointer_auth.c | 47 | ||||
| -rw-r--r-- | include/uapi/linux/prctl.h | 8 | ||||
| -rw-r--r-- | kernel/sys.c | 8 |
6 files changed, 71 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/pointer_auth.h b/arch/arm64/include/asm/pointer_auth.h index 5ccf49b4dac3..80eb03afd677 100644 --- a/arch/arm64/include/asm/pointer_auth.h +++ b/arch/arm64/include/asm/pointer_auth.h @@ -63,6 +63,8 @@ static inline void ptrauth_keys_switch(struct ptrauth_keys *keys) __ptrauth_key_install(APGA, keys->apga); } +extern int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg); + /* * The EL0 pointer bits used by a pointer authentication code. * This is dependent on TBI0 being enabled, or bits 63:56 would also apply. @@ -86,6 +88,7 @@ do { \ ptrauth_keys_switch(&(tsk)->thread_info.keys_user) #else /* CONFIG_ARM64_PTR_AUTH */ +#define ptrauth_prctl_reset_keys(tsk, arg) (-EINVAL) #define ptrauth_strip_insn_pac(lr) (lr) #define ptrauth_thread_init_user(tsk) #define ptrauth_thread_switch(tsk) diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index f4b8e09aff56..142c708cb429 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -44,6 +44,7 @@ #include <asm/hw_breakpoint.h> #include <asm/lse.h> #include <asm/pgtable-hwdef.h> +#include <asm/pointer_auth.h> #include <asm/ptrace.h> #include <asm/types.h> @@ -289,6 +290,9 @@ extern void __init minsigstksz_setup(void); #define SVE_SET_VL(arg) sve_set_current_vl(arg) #define SVE_GET_VL() sve_get_current_vl() +/* PR_PAC_RESET_KEYS prctl */ +#define PAC_RESET_KEYS(tsk, arg) ptrauth_prctl_reset_keys(tsk, arg) + /* * For CONFIG_GCC_PLUGIN_STACKLEAK * diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 583334ce1c2c..df08d735b21d 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -58,6 +58,7 @@ arm64-obj-$(CONFIG_CRASH_DUMP) += crash_dump.o arm64-obj-$(CONFIG_CRASH_CORE) += crash_core.o arm64-obj-$(CONFIG_ARM_SDE_INTERFACE) += sdei.o arm64-obj-$(CONFIG_ARM64_SSBD) += ssbd.o +arm64-obj-$(CONFIG_ARM64_PTR_AUTH) += pointer_auth.o obj-y += $(arm64-obj-y) vdso/ probes/ obj-m += $(arm64-obj-m) diff --git a/arch/arm64/kernel/pointer_auth.c b/arch/arm64/kernel/pointer_auth.c new file mode 100644 index 000000000000..b9f6f5f3409a --- /dev/null +++ b/arch/arm64/kernel/pointer_auth.c @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/errno.h> +#include <linux/prctl.h> +#include <linux/random.h> +#include <linux/sched.h> +#include <asm/cpufeature.h> +#include <asm/pointer_auth.h> + +int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg) +{ + struct ptrauth_keys *keys = &tsk->thread_info.keys_user; + unsigned long addr_key_mask = PR_PAC_APIAKEY | PR_PAC_APIBKEY | + PR_PAC_APDAKEY | PR_PAC_APDBKEY; + unsigned long key_mask = addr_key_mask | PR_PAC_APGAKEY; + + if (!system_supports_address_auth() && !system_supports_generic_auth()) + return -EINVAL; + + if (!arg) { + ptrauth_keys_init(keys); + ptrauth_keys_switch(keys); + return 0; + } + + if (arg & ~key_mask) + return -EINVAL; + + if (((arg & addr_key_mask) && !system_supports_address_auth()) || + ((arg & PR_PAC_APGAKEY) && !system_supports_generic_auth())) + return -EINVAL; + + if (arg & PR_PAC_APIAKEY) + get_random_bytes(&keys->apia, sizeof(keys->apia)); + if (arg & PR_PAC_APIBKEY) + get_random_bytes(&keys->apib, sizeof(keys->apib)); + if (arg & PR_PAC_APDAKEY) + get_random_bytes(&keys->apda, sizeof(keys->apda)); + if (arg & PR_PAC_APDBKEY) + get_random_bytes(&keys->apdb, sizeof(keys->apdb)); + if (arg & PR_PAC_APGAKEY) + get_random_bytes(&keys->apga, sizeof(keys->apga)); + + ptrauth_keys_switch(keys); + + return 0; +} diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index c0d7ea0bf5b6..0f535a501391 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -219,4 +219,12 @@ struct prctl_mm_map { # define PR_SPEC_DISABLE (1UL << 2) # define PR_SPEC_FORCE_DISABLE (1UL << 3) +/* Reset arm64 pointer authentication keys */ +#define PR_PAC_RESET_KEYS 54 +# define PR_PAC_APIAKEY (1UL << 0) +# define PR_PAC_APIBKEY (1UL << 1) +# define PR_PAC_APDAKEY (1UL << 2) +# define PR_PAC_APDBKEY (1UL << 3) +# define PR_PAC_APGAKEY (1UL << 4) + #endif /* _LINUX_PRCTL_H */ diff --git a/kernel/sys.c b/kernel/sys.c index 123bd73046ec..64b5a230f38d 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -121,6 +121,9 @@ #ifndef SVE_GET_VL # define SVE_GET_VL() (-EINVAL) #endif +#ifndef PAC_RESET_KEYS +# define PAC_RESET_KEYS(a, b) (-EINVAL) +#endif /* * this is where the system-wide overflow UID and GID are defined, for @@ -2476,6 +2479,11 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, return -EINVAL; error = arch_prctl_spec_ctrl_set(me, arg2, arg3); break; + case PR_PAC_RESET_KEYS: + if (arg3 || arg4 || arg5) + return -EINVAL; + error = PAC_RESET_KEYS(me, arg2); + break; default: error = -EINVAL; break; |