Commit 57849de1 authored Dec 31, 2017 by Thomas Gleixner Committed by Greg Kroah-Hartman Jan 02, 2018

x86/ldt: Make LDT pgtable free conditional



commit 7f414195b0c3612acd12b4611a5fe75995cf10c7 upstream.

Andy prefers to be paranoid about the pagetable free in the error path of
write_ldt(). Make it conditional and warn whenever the installment of a
secondary LDT fails.

Requested-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 3e133155

arch/x86/kernel/ldt.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -426,6 +426,7 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
		* already installed then the PTE page is already
		* populated. Mop up a half populated page table.
		*/
		if (!WARN_ON_ONCE(old_ldt))
		free_ldt_pgtables(mm);
		free_ldt_struct(new_ldt);
		goto out_unlock;