From 429733db42fadd6566a5fa0e11433943c0cd8cb0 Mon Sep 17 00:00:00 2001 From: Sami Tolvanen Date: Thu, 10 Sep 2020 15:46:59 -0700 Subject: [PATCH] ANDROID: lkdtm: use __va_function To ensure we take the actual address of a function in kernel text, use __va_function. Otherwise, with CONFIG_CFI_CLANG, the compiler may replace the address with a pointer to the CFI jump table, which can reside inside the module, when compiled with CONFIG_LKDTM=m. Bug: 145210207 Change-Id: Ie65d3aace55695a5e515436267c048b13ace9002 Signed-off-by: Sami Tolvanen --- drivers/misc/lkdtm/usercopy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/misc/lkdtm/usercopy.c b/drivers/misc/lkdtm/usercopy.c index 109e8d4302c1..d173d6175c87 100644 --- a/drivers/misc/lkdtm/usercopy.c +++ b/drivers/misc/lkdtm/usercopy.c @@ -314,7 +314,7 @@ void lkdtm_USERCOPY_KERNEL(void) pr_info("attempting bad copy_to_user from kernel text: %px\n", vm_mmap); - if (copy_to_user((void __user *)user_addr, vm_mmap, + if (copy_to_user((void __user *)user_addr, __va_function(vm_mmap), unconst + PAGE_SIZE)) { pr_warn("copy_to_user failed, but lacked Oops\n"); goto free_user;