diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2023-01-09 18:47:59 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2023-01-20 14:26:18 +0000 |
| commit | 2198d07c509f1db4a1185d1f65aaada794c6ea59 (patch) | |
| tree | 959c8deb4f69da3440f51b57bd907b4af036f602 /arch/arm64/kernel/entry.S | |
| parent | b7bfaa761d760e72a969d116517eaa12e404c262 (diff) | |
arm64: Always load shadow stack pointer directly from the task struct
All occurrences of the scs_load macro load the value of the shadow call
stack pointer from the task which is current at that point. So instead
of taking a task struct register argument in the scs_load macro to
specify the task struct to load from, let's always reference the current
task directly. This should make it much harder to exploit any
instruction sequences reloading the shadow call stack pointer register
from memory.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230109174800.3286265-2-ardb@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/entry.S')
| -rw-r--r-- | arch/arm64/kernel/entry.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 11cb99c4d298..546f7773238e 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -275,7 +275,7 @@ alternative_if ARM64_HAS_ADDRESS_AUTH alternative_else_nop_endif 1: - scs_load tsk + scs_load_current .else add x21, sp, #PT_REGS_SIZE get_current_task tsk @@ -848,7 +848,7 @@ SYM_FUNC_START(cpu_switch_to) msr sp_el0, x1 ptrauth_keys_install_kernel x1, x8, x9, x10 scs_save x0 - scs_load x1 + scs_load_current ret SYM_FUNC_END(cpu_switch_to) NOKPROBE(cpu_switch_to) |