lkml.org 
[lkml]   [2018]   [Sep]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.18 096/235] x86/mm/pti: Add an overflow check to pti_clone_pmds()
    Date
    4.18-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Joerg Roedel <jroedel@suse.de>

    [ Upstream commit 935232ce28dfabff1171e5a7113b2d865fa9ee63 ]

    The addr counter will overflow if the last PMD of the address space is
    cloned, resulting in an endless loop.

    Check for that and bail out of the loop when it happens.

    Signed-off-by: Joerg Roedel <jroedel@suse.de>
    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    Tested-by: Pavel Machek <pavel@ucw.cz>
    Cc: "H . Peter Anvin" <hpa@zytor.com>
    Cc: linux-mm@kvack.org
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Andy Lutomirski <luto@kernel.org>
    Cc: Dave Hansen <dave.hansen@intel.com>
    Cc: Josh Poimboeuf <jpoimboe@redhat.com>
    Cc: Juergen Gross <jgross@suse.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Jiri Kosina <jkosina@suse.cz>
    Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
    Cc: Brian Gerst <brgerst@gmail.com>
    Cc: David Laight <David.Laight@aculab.com>
    Cc: Denys Vlasenko <dvlasenk@redhat.com>
    Cc: Eduardo Valentin <eduval@amazon.com>
    Cc: Greg KH <gregkh@linuxfoundation.org>
    Cc: Will Deacon <will.deacon@arm.com>
    Cc: aliguori@amazon.com
    Cc: daniel.gruss@iaik.tugraz.at
    Cc: hughd@google.com
    Cc: keescook@google.com
    Cc: Andrea Arcangeli <aarcange@redhat.com>
    Cc: Waiman Long <llong@redhat.com>
    Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
    Cc: joro@8bytes.org
    Link: https://lkml.kernel.org/r/1531906876-13451-25-git-send-email-joro@8bytes.org
    Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    arch/x86/mm/pti.c | 4 ++++
    1 file changed, 4 insertions(+)

    --- a/arch/x86/mm/pti.c
    +++ b/arch/x86/mm/pti.c
    @@ -306,6 +306,10 @@ pti_clone_pmds(unsigned long start, unsi
    p4d_t *p4d;
    pud_t *pud;

    + /* Overflow check */
    + if (addr < start)
    + break;
    +
    pgd = pgd_offset_k(addr);
    if (WARN_ON(pgd_none(*pgd)))
    return;

    \
     
     \ /
      Last update: 2018-09-24 14:36    [W:4.034 / U:1.848 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site