Re: [PATCH 4.4 037/107] x86/mm: Factor out LDT init from context init

On Mon, 2018-07-23 at 14:41 +0200, Greg Kroah-Hartman wrote:

4.4-stable review patch.  If anyone has any objections, please let me know.

---

From: Dave Hansen dave.hansen@linux.intel.com

commit 39a0526fb3f7d93433d146304278477eb463f8af upstream

[...]

--- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h

[...]

+static inline int init_new_context(struct task_struct *tsk,

• 		   struct mm_struct *mm)
  

+{

• init_new_context_ldt(tsk, mm);
• return 0;

+}

[...]

This hides errors from init_new_context_ldt(), which is very bad. Fixed upstream by:

commit ccd5b3235180eef3cfec337df1c8554ab151b5cc Author: Eric Biggers ebiggers@google.com Date: Thu Aug 24 10:50:29 2017 -0700

x86/mm: Fix use-after-free of ldt_struct

Ben.