Message ID | 1460988283-17054-2-git-send-email-luis.henriques@canonical.com |
---|---|
State | New |
Headers | show |
Clean cherry-pick, fixes CVE, no newer upstream patches that change this. --chris On Mon, Apr 18, 2016 at 03:04:43PM +0100, Luis Henriques wrote: > From: Vasily Kulikov <segoon@openwall.com> > > Poison pointer values should be small enough to find a room in > non-mmap'able/hardly-mmap'able space. E.g. on x86 "poison pointer space" > is located starting from 0x0. Given unprivileged users cannot mmap > anything below mmap_min_addr, it should be safe to use poison pointers > lower than mmap_min_addr. > > The current poison pointer values of LIST_POISON{1,2} might be too big for > mmap_min_addr values equal or less than 1 MB (common case, e.g. Ubuntu > uses only 0x10000). There is little point to use such a big value given > the "poison pointer space" below 1 MB is not yet exhausted. Changing it > to a smaller value solves the problem for small mmap_min_addr setups. > > The values are suggested by Solar Designer: > http://www.openwall.com/lists/oss-security/2015/05/02/6 > > Signed-off-by: Vasily Kulikov <segoon@openwall.com> > Cc: Solar Designer <solar@openwall.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> > (cherry picked from commit 8a5e5e02fc83aaf67053ab53b359af08c6c49aaf) > CVE-2016-0821 > BugLink: https://bugs.launchpad.net/bugs/1561389 > Signed-off-by: Luis Henriques <luis.henriques@canonical.com> > --- > include/linux/poison.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/include/linux/poison.h b/include/linux/poison.h > index 2110a81c5e2a..253c9b4198ef 100644 > --- a/include/linux/poison.h > +++ b/include/linux/poison.h > @@ -19,8 +19,8 @@ > * under normal circumstances, used to verify that nobody uses > * non-initialized list entries. > */ > -#define LIST_POISON1 ((void *) 0x00100100 + POISON_POINTER_DELTA) > -#define LIST_POISON2 ((void *) 0x00200200 + POISON_POINTER_DELTA) > +#define LIST_POISON1 ((void *) 0x100 + POISON_POINTER_DELTA) > +#define LIST_POISON2 ((void *) 0x200 + POISON_POINTER_DELTA) > > /********** include/linux/timer.h **********/ > /* > > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com > https://lists.ubuntu.com/mailman/listinfo/kernel-team >
diff --git a/include/linux/poison.h b/include/linux/poison.h index 2110a81c5e2a..253c9b4198ef 100644 --- a/include/linux/poison.h +++ b/include/linux/poison.h @@ -19,8 +19,8 @@ * under normal circumstances, used to verify that nobody uses * non-initialized list entries. */ -#define LIST_POISON1 ((void *) 0x00100100 + POISON_POINTER_DELTA) -#define LIST_POISON2 ((void *) 0x00200200 + POISON_POINTER_DELTA) +#define LIST_POISON1 ((void *) 0x100 + POISON_POINTER_DELTA) +#define LIST_POISON2 ((void *) 0x200 + POISON_POINTER_DELTA) /********** include/linux/timer.h **********/ /*