From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59863 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752356AbcEAWQX (ORCPT ); Sun, 1 May 2016 18:16:23 -0400 Subject: Patch "x86/mm/xen: Suppress hugetlbfs in PV guests" has been added to the 4.5-stable tree To: JBeulich@suse.com, JGross@suse.com, akpm@linux-foundation.org, boris.ostrovsky@oracle.com, bp@alien8.de, brgerst@gmail.com, david.vrabel@citrix.com, dvlasenk@redhat.com, gregkh@linuxfoundation.org, hpa@zytor.com, jbeulich@suse.com, luto@amacapital.net, mcgrof@suse.com, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de, torvalds@linux-foundation.org, toshi.kani@hp.com, vkuznets@redhat.com, xen-devel@lists.xenproject.org Cc: , From: Date: Sun, 01 May 2016 15:16:22 -0700 Message-ID: <146214098217590@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled x86/mm/xen: Suppress hugetlbfs in PV guests to the 4.5-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-mm-xen-suppress-hugetlbfs-in-pv-guests.patch and it can be found in the queue-4.5 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 103f6112f253017d7062cd74d17f4a514ed4485c Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Thu, 21 Apr 2016 00:27:04 -0600 Subject: x86/mm/xen: Suppress hugetlbfs in PV guests From: Jan Beulich commit 103f6112f253017d7062cd74d17f4a514ed4485c upstream. Huge pages are not normally available to PV guests. Not suppressing hugetlbfs use results in an endless loop of page faults when user mode code tries to access a hugetlbfs mapped area (since the hypervisor denies such PTEs to be created, but error indications can't be propagated out of xen_set_pte_at(), just like for various of its siblings), and - once killed in an oops like this: kernel BUG at .../fs/hugetlbfs/inode.c:428! invalid opcode: 0000 [#1] SMP ... RIP: e030:[] [] remove_inode_hugepages+0x25b/0x320 ... Call Trace: [] hugetlbfs_evict_inode+0x15/0x40 [] evict+0xbd/0x1b0 [] __dentry_kill+0x19a/0x1f0 [] dput+0x1fe/0x220 [] __fput+0x155/0x200 [] task_work_run+0x60/0xa0 [] do_exit+0x160/0x400 [] do_group_exit+0x3b/0xa0 [] get_signal+0x1ed/0x470 [] do_signal+0x14/0x110 [] prepare_exit_to_usermode+0xe9/0xf0 [] retint_user+0x8/0x13 This is CVE-2016-3961 / XSA-174. Reported-by: Vitaly Kuznetsov Signed-off-by: Jan Beulich Cc: Andrew Morton Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Brian Gerst Cc: David Vrabel Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Juergen Gross Cc: Linus Torvalds Cc: Luis R. Rodriguez Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Toshi Kani Cc: xen-devel Link: http://lkml.kernel.org/r/57188ED802000078000E431C@prv-mh.provo.novell.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/hugetlb.h | 1 + 1 file changed, 1 insertion(+) --- a/arch/x86/include/asm/hugetlb.h +++ b/arch/x86/include/asm/hugetlb.h @@ -4,6 +4,7 @@ #include #include +#define hugepages_supported() cpu_has_pse static inline int is_hugepage_only_range(struct mm_struct *mm, unsigned long addr, Patches currently in stable-queue which might be from JBeulich@suse.com are queue-4.5/x86-mm-xen-suppress-hugetlbfs-in-pv-guests.patch