arm64: Tighten the PR_{SET, GET}_TAGGED_ADDR_CTRL prctl() unused arguments

Require that arg{3,4,5} of the PR_{SET,GET}_TAGGED_ADDR_CTRL prctl and
arg2 of the PR_GET_TAGGED_ADDR_CTRL prctl() are zero rather than ignored
for future extensions.

Acked-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/kernel/sys.c b/kernel/sys.c
index c6c4d53..ec48396 100644 (file)
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -2499,9 +2499,13 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
                error = PAC_RESET_KEYS(me, arg2);
                break;
        case PR_SET_TAGGED_ADDR_CTRL:
+               if (arg3 || arg4 || arg5)
+                       return -EINVAL;
                error = SET_TAGGED_ADDR_CTRL(arg2);
                break;
        case PR_GET_TAGGED_ADDR_CTRL:
+               if (arg2 || arg3 || arg4 || arg5)
+                       return -EINVAL;
                error = GET_TAGGED_ADDR_CTRL();
                break;
        default: