From: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Date: Tue, 1 Feb 2022 15:40:55 +0100
Subject: x86/fault: Cast an argument to the proper address space in prefetch()
Git-commit: 944fad4583bc8a6d7dd80fbe39db50141da95793
Patch-mainline: v5.19-rc1
References: git-fixes
Commit in Fixes uses accessors based on the access mode, i.e., it
distinguishes its access if instr carries a user address or a kernel
address.
Since that commit, sparse complains about passing an argument without
__user annotation to get_user(), which expects a pointer of the __user
address space:
arch/x86/mm/fault.c:152:29: warning: incorrect type in argument 1 (different address spaces)
arch/x86/mm/fault.c:152:29: expected void const volatile [noderef] __user *ptr
arch/x86/mm/fault.c:152:29: got unsigned char *[assigned] instr
Cast instr to __user when accessing user memory.
No functional change. No change in the generated object code.
[ bp: Simplify commit message. ]
Fixes: 35f1c89b0cce ("x86/fault: Fix AMD erratum #91 errata fixup for user code")
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220201144055.5670-1-lukas.bulwahn@gmail.com
Acked-by: Nikolay Borisov <nik.borisov@suse.com>
---
arch/x86/mm/fault.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index d0074c6ed31a..fad8faa29d04 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -149,7 +149,7 @@ is_prefetch(struct pt_regs *regs, unsigned long error_code, unsigned long addr)
unsigned char opcode;
if (user_mode(regs)) {
- if (get_user(opcode, instr))
+ if (get_user(opcode, (unsigned char __user *) instr))
break;
} else {
if (get_kernel_nofault(opcode, instr))