[PATCH v2 5/5] arm64: kernel: Don't toggle PAN on systems with UAO
From: catalin.marinas@arm.com (Catalin Marinas)
Date: 2016-02-18 14:36:48
On Fri, Feb 05, 2016 at 02:58:50PM +0000, James Morse wrote:
quoted hunk ↗ jump to hunk
--- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c@@ -234,6 +234,9 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, } if (permission_fault(esr) && (addr < USER_DS)) { + if (get_thread_info(regs->sp)->addr_limit == KERNEL_DS) + panic("Accessing user space memory with fs=KERNEL_DS");
We could simply use "get_fs() == KERNEL_DS" as we should call do_page_fault() outside the current context. -- Catalin