From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andy Lutomirski , Thomas Gleixner Subject: [PATCH 4.14 144/146] x86/ldt: Make LDT pgtable free conditional Date: Mon, 1 Jan 2018 15:38:55 +0100 Message-Id: <20180101140144.557697823@linuxfoundation.org> In-Reply-To: <20180101140123.743014891@linuxfoundation.org> References: <20180101140123.743014891@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner 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 Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/ldt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -426,7 +426,8 @@ static int write_ldt(void __user *ptr, u * already installed then the PTE page is already * populated. Mop up a half populated page table. */ - free_ldt_pgtables(mm); + if (!WARN_ON_ONCE(old_ldt)) + free_ldt_pgtables(mm); free_ldt_struct(new_ldt); goto out_unlock; }