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| author | Jan Beulich <JBeulich@suse.com> | 2016-04-21 08:27:04 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-04-22 10:05:00 +0200 |
| commit | 103f6112f253017d7062cd74d17f4a514ed4485c (patch) | |
| tree | 1e393c429bb4fe6e30b9f65a3200dca882e7a0d4 | |
| parent | x86/doc: Correct limits in Documentation/x86/x86_64/mm.txt (diff) | |
| download | linux-103f6112f253017d7062cd74d17f4a514ed4485c.tar.xz linux-103f6112f253017d7062cd74d17f4a514ed4485c.zip | |
x86/mm/xen: Suppress hugetlbfs in PV guests
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:[<ffffffff811c333b>] [<ffffffff811c333b>] remove_inode_hugepages+0x25b/0x320
...
Call Trace:
[<ffffffff811c3415>] hugetlbfs_evict_inode+0x15/0x40
[<ffffffff81167b3d>] evict+0xbd/0x1b0
[<ffffffff8116514a>] __dentry_kill+0x19a/0x1f0
[<ffffffff81165b0e>] dput+0x1fe/0x220
[<ffffffff81150535>] __fput+0x155/0x200
[<ffffffff81079fc0>] task_work_run+0x60/0xa0
[<ffffffff81063510>] do_exit+0x160/0x400
[<ffffffff810637eb>] do_group_exit+0x3b/0xa0
[<ffffffff8106e8bd>] get_signal+0x1ed/0x470
[<ffffffff8100f854>] do_signal+0x14/0x110
[<ffffffff810030e9>] prepare_exit_to_usermode+0xe9/0xf0
[<ffffffff814178a5>] retint_user+0x8/0x13
This is CVE-2016-3961 / XSA-174.
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <JGross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: stable@vger.kernel.org
Cc: xen-devel <xen-devel@lists.xenproject.org>
Link: http://lkml.kernel.org/r/57188ED802000078000E431C@prv-mh.provo.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/include/asm/hugetlb.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/hugetlb.h b/arch/x86/include/asm/hugetlb.h index f8a29d2c97b0..e6a8613fbfb0 100644 --- a/arch/x86/include/asm/hugetlb.h +++ b/arch/x86/include/asm/hugetlb.h @@ -4,6 +4,7 @@ #include <asm/page.h> #include <asm-generic/hugetlb.h> +#define hugepages_supported() cpu_has_pse static inline int is_hugepage_only_range(struct mm_struct *mm, unsigned long addr, |