diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c index de87693cf557..cc92bc3ed820 100644 --- a/drivers/misc/lkdtm/bugs.c +++ b/drivers/misc/lkdtm/bugs.c @@ -378,3 +378,39 @@ void lkdtm_DOUBLE_FAULT(void) pr_err("XFAIL: this test is ia32-only\n"); #endif } + +#ifdef CONFIG_ARM64_PTR_AUTH +static noinline void change_pac_parameters(void) +{ + /* Reset the keys of current task */ + ptrauth_thread_init_kernel(current); + ptrauth_thread_switch_kernel(current); +} + +#define CORRUPT_PAC_ITERATE 10 +noinline void lkdtm_CORRUPT_PAC(void) +{ + int i; + + if (!system_supports_address_auth()) { + pr_err("FAIL: arm64 pointer authentication feature not present\n"); + return; + } + + pr_info("Change the PAC parameters to force function return failure\n"); + /* + * Pac is a hash value computed from input keys, return address and + * stack pointer. As pac has fewer bits so there is a chance of + * collision, so iterate few times to reduce the collision probability. + */ + for (i = 0; i < CORRUPT_PAC_ITERATE; i++) + change_pac_parameters(); + + pr_err("FAIL: %s test failed. Kernel may be unstable from here\n", __func__); +} +#else /* !CONFIG_ARM64_PTR_AUTH */ +noinline void lkdtm_CORRUPT_PAC(void) +{ + pr_err("FAIL: arm64 pointer authentication config disabled\n"); +} +#endif diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c index ee0d6e721441..5ce4ac8c06fc 100644 --- a/drivers/misc/lkdtm/core.c +++ b/drivers/misc/lkdtm/core.c @@ -116,6 +116,7 @@ static const struct crashtype crashtypes[] = { CRASHTYPE(STACK_GUARD_PAGE_LEADING), CRASHTYPE(STACK_GUARD_PAGE_TRAILING), CRASHTYPE(UNSET_SMEP), + CRASHTYPE(CORRUPT_PAC), CRASHTYPE(UNALIGNED_LOAD_STORE_WRITE), CRASHTYPE(OVERWRITE_ALLOCATION), CRASHTYPE(WRITE_AFTER_FREE), diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h index c56d23e37643..8d13d0176624 100644 --- a/drivers/misc/lkdtm/lkdtm.h +++ b/drivers/misc/lkdtm/lkdtm.h @@ -31,6 +31,7 @@ void lkdtm_UNSET_SMEP(void); #ifdef CONFIG_X86_32 void lkdtm_DOUBLE_FAULT(void); #endif +void lkdtm_CORRUPT_PAC(void); /* lkdtm_heap.c */ void __init lkdtm_heap_init(void);