From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Haoran Wang <[email protected]> Date: Thu, 16 Oct 2026 10:00:00 +0800 Subject: [PATCH] tracing/syscalls: use copy_from_user for the faultable syscall buffer
syscall_copy_user_array() copies the buffer argument of faultable syscalls (write, pwrite64, ...) with __copy_from_user(), which skips access_ok(). Use copy_from_user() instead so a non-user address is rejected and the entry is recorded as faulted. It could be a security concern for machines that trust perf a bit too much. Signed-off-by: Haoran Wang <[email protected]> --- kernel/trace/trace_syscalls.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -682,7 +682,7 @@ for (int i = 0; i < args->uargs; i++, buf += SYSCALL_FAULT_ARG_SZ) { ptr = (char __user *)args->ptr_array[i]; - ret = __copy_from_user(buf, ptr, size); + ret = copy_from_user(buf, ptr, size); args->read[i] = ret ? -1 : size; } return 0; -- 2.43.0
