1. 04 May, 2016 12 commits
    • Kees Cook's avatar
      mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE · 350e988f
      Kees Cook authored
      commit 204db6ed upstream.
      
      The arch_randomize_brk() function is used on several architectures,
      even those that don't support ET_DYN ASLR. To avoid bulky extern/#define
      tricks, consolidate the support under CONFIG_ARCH_HAS_ELF_RANDOMIZE for
      the architectures that support it, while still handling CONFIG_COMPAT_BRK.
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Cc: Hector Marco-Gisbert <hecmargi@upv.es>
      Cc: Russell King <linux@arm.linux.org.uk>
      Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: "David A. Long" <dave.long@linaro.org>
      Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
      Cc: Arun Chandran <achandran@mvista.com>
      Cc: Yann Droneaud <ydroneaud@opteya.com>
      Cc: Min-Hua Chen <orca.chen@gmail.com>
      Cc: Paul Burton <paul.burton@imgtec.com>
      Cc: Alex Smith <alex@alex-smith.me.uk>
      Cc: Markos Chandras <markos.chandras@imgtec.com>
      Cc: Vineeth Vijayan <vvijayan@mvista.com>
      Cc: Jeff Bailey <jeffbailey@google.com>
      Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
      Cc: Ben Hutchings <ben@decadent.org.uk>
      Cc: Behan Webster <behanw@converseincode.com>
      Cc: Ismael Ripoll <iripoll@upv.es>
      Cc: Jan-Simon Mller <dl9pf@gmx.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      350e988f
    • Kees Cook's avatar
      mm: split ET_DYN ASLR from mmap ASLR · e19d0939
      Kees Cook authored
      commit d1fd836d upstream.
      
      This fixes the "offset2lib" weakness in ASLR for arm, arm64, mips,
      powerpc, and x86.  The problem is that if there is a leak of ASLR from
      the executable (ET_DYN), it means a leak of shared library offset as
      well (mmap), and vice versa.  Further details and a PoC of this attack
      is available here:
      
        http://cybersecurity.upv.es/attacks/offset2lib/offset2lib.html
      
      With this patch, a PIE linked executable (ET_DYN) has its own ASLR
      region:
      
        $ ./show_mmaps_pie
        54859ccd6000-54859ccd7000 r-xp  ...  /tmp/show_mmaps_pie
        54859ced6000-54859ced7000 r--p  ...  /tmp/show_mmaps_pie
        54859ced7000-54859ced8000 rw-p  ...  /tmp/show_mmaps_pie
        7f75be764000-7f75be91f000 r-xp  ...  /lib/x86_64-linux-gnu/libc.so.6
        7f75be91f000-7f75beb1f000 ---p  ...  /lib/x86_64-linux-gnu/libc.so.6
        7f75beb1f000-7f75beb23000 r--p  ...  /lib/x86_64-linux-gnu/libc.so.6
        7f75beb23000-7f75beb25000 rw-p  ...  /lib/x86_64-linux-gnu/libc.so.6
        7f75beb25000-7f75beb2a000 rw-p  ...
        7f75beb2a000-7f75beb4d000 r-xp  ...  /lib64/ld-linux-x86-64.so.2
        7f75bed45000-7f75bed46000 rw-p  ...
        7f75bed46000-7f75bed47000 r-xp  ...
        7f75bed47000-7f75bed4c000 rw-p  ...
        7f75bed4c000-7f75bed4d000 r--p  ...  /lib64/ld-linux-x86-64.so.2
        7f75bed4d000-7f75bed4e000 rw-p  ...  /lib64/ld-linux-x86-64.so.2
        7f75bed4e000-7f75bed4f000 rw-p  ...
        7fffb3741000-7fffb3762000 rw-p  ...  [stack]
        7fffb377b000-7fffb377d000 r--p  ...  [vvar]
        7fffb377d000-7fffb377f000 r-xp  ...  [vdso]
      
      The change is to add a call the newly created arch_mmap_rnd() into the
      ELF loader for handling ET_DYN ASLR in a separate region from mmap ASLR,
      as was already done on s390.  Removes CONFIG_BINFMT_ELF_RANDOMIZE_PIE,
      which is no longer needed.
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Reported-by: default avatarHector Marco-Gisbert <hecmargi@upv.es>
      Cc: Russell King <linux@arm.linux.org.uk>
      Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: "David A. Long" <dave.long@linaro.org>
      Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
      Cc: Arun Chandran <achandran@mvista.com>
      Cc: Yann Droneaud <ydroneaud@opteya.com>
      Cc: Min-Hua Chen <orca.chen@gmail.com>
      Cc: Paul Burton <paul.burton@imgtec.com>
      Cc: Alex Smith <alex@alex-smith.me.uk>
      Cc: Markos Chandras <markos.chandras@imgtec.com>
      Cc: Vineeth Vijayan <vvijayan@mvista.com>
      Cc: Jeff Bailey <jeffbailey@google.com>
      Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
      Cc: Ben Hutchings <ben@decadent.org.uk>
      Cc: Behan Webster <behanw@converseincode.com>
      Cc: Ismael Ripoll <iripoll@upv.es>
      Cc: Jan-Simon Mller <dl9pf@gmx.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      e19d0939
    • Kees Cook's avatar
      s390: redefine randomize_et_dyn for ELF_ET_DYN_BASE · 2d325291
      Kees Cook authored
      commit c6f5b001 upstream.
      
      In preparation for moving ET_DYN randomization into the ELF loader (which
      requires a static ELF_ET_DYN_BASE), this redefines s390's existing ET_DYN
      randomization in a call to arch_mmap_rnd(). This refactoring results in
      the same ET_DYN randomization on s390.
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Acked-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      2d325291
    • Kees Cook's avatar
      mm: expose arch_mmap_rnd when available · 97c9ce2a
      Kees Cook authored
      commit 2b68f6ca upstream.
      
      When an architecture fully supports randomizing the ELF load location,
      a per-arch mmap_rnd() function is used to find a randomized mmap base.
      In preparation for randomizing the location of ET_DYN binaries
      separately from mmap, this renames and exports these functions as
      arch_mmap_rnd(). Additionally introduces CONFIG_ARCH_HAS_ELF_RANDOMIZE
      for describing this feature on architectures that support it
      (which is a superset of ARCH_BINFMT_ELF_RANDOMIZE_PIE, since s390
      already supports a separated ET_DYN ASLR from mmap ASLR without the
      ARCH_BINFMT_ELF_RANDOMIZE_PIE logic).
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Cc: Hector Marco-Gisbert <hecmargi@upv.es>
      Cc: Russell King <linux@arm.linux.org.uk>
      Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: "David A. Long" <dave.long@linaro.org>
      Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
      Cc: Arun Chandran <achandran@mvista.com>
      Cc: Yann Droneaud <ydroneaud@opteya.com>
      Cc: Min-Hua Chen <orca.chen@gmail.com>
      Cc: Paul Burton <paul.burton@imgtec.com>
      Cc: Alex Smith <alex@alex-smith.me.uk>
      Cc: Markos Chandras <markos.chandras@imgtec.com>
      Cc: Vineeth Vijayan <vvijayan@mvista.com>
      Cc: Jeff Bailey <jeffbailey@google.com>
      Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
      Cc: Ben Hutchings <ben@decadent.org.uk>
      Cc: Behan Webster <behanw@converseincode.com>
      Cc: Ismael Ripoll <iripoll@upv.es>
      Cc: Jan-Simon Mller <dl9pf@gmx.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      97c9ce2a
    • Kees Cook's avatar
      s390: standardize mmap_rnd() usage · 58eb8cee
      Kees Cook authored
      commit 8e89a356 upstream.
      
      In preparation for splitting out ET_DYN ASLR, this refactors the use of
      mmap_rnd() to be used similarly to arm and x86, and extracts the
      checking of PF_RANDOMIZE.
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Acked-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      58eb8cee
    • Martin Schwidefsky's avatar
      s390/mm: align 64-bit PIE binaries to 4GB · 3a86395e
      Martin Schwidefsky authored
      commit 4ba2815d upstream.
      
      The base address (STACK_TOP / 3 * 2) for a 64-bit program is two thirds
      into the 4GB segment at 0x2aa00000000. The randomization added on z13
      can eat another 1GB of the remaining 1.33GB to the next 4GB boundary.
      In the worst case 300MB are left for the executable + bss which may
      cross into the next 4GB segment. This is bad for branch prediction,
      therefore align the base address to 4GB to give the program more room
      before it crosses the 4GB boundary.
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      3a86395e
    • Martin Schwidefsky's avatar
      s390: avoid z13 cache aliasing · 7ae77468
      Martin Schwidefsky authored
      commit 1f6b83e5 upstream.
      
      Avoid cache aliasing on z13 by aligning shared objects to multiples
      of 512K. The virtual addresses of a page from a shared file needs
      to have identical bits in the range 2^12 to 2^18.
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      7ae77468
    • Kees Cook's avatar
      powerpc: standardize mmap_rnd() usage · e108721a
      Kees Cook authored
      commit ed632274 upstream.
      
      In preparation for splitting out ET_DYN ASLR, this refactors the use of
      mmap_rnd() to be used similarly to arm and x86.
      
      (Can mmap ASLR be safely enabled in the legacy mmap case here?  Other
      archs use "mm->mmap_base = TASK_UNMAPPED_BASE + random_factor".)
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      e108721a
    • Kees Cook's avatar
      mips: extract logic for mmap_rnd() · 10811a1a
      Kees Cook authored
      commit 1f0569df upstream.
      
      In preparation for splitting out ET_DYN ASLR, extract the mmap ASLR
      selection into a separate function.
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      10811a1a
    • Kees Cook's avatar
      arm64: standardize mmap_rnd() usage · 9fe06561
      Kees Cook authored
      commit dd04cff1 upstream.
      
      In preparation for splitting out ET_DYN ASLR, this refactors the use of
      mmap_rnd() to be used similarly to arm and x86.  This additionally
      enables mmap ASLR on legacy mmap layouts, which appeared to be missing
      on arm64, and was already supported on arm.  Additionally removes a
      copy/pasted declaration of an unused function.
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      9fe06561
    • Kees Cook's avatar
      x86: standardize mmap_rnd() usage · 42658474
      Kees Cook authored
      commit 82168140 upstream.
      
      In preparation for splitting out ET_DYN ASLR, this refactors the use of
      mmap_rnd() to be used similarly to arm, and extracts the checking of
      PF_RANDOMIZE.
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      [ kamal: 3.19-stable prereq for 8b8addf8
        "x86/mm/32: Enable full randomization on i386 and X86_32" ]
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      42658474
    • Kees Cook's avatar
      arm: factor out mmap ASLR into mmap_rnd · a7c8c37b
      Kees Cook authored
      commit fbbc400f upstream.
      
      To address the "offset2lib" ASLR weakness[1], this separates ET_DYN ASLR
      from mmap ASLR, as already done on s390.  The architectures that are
      already randomizing mmap (arm, arm64, mips, powerpc, s390, and x86), have
      their various forms of arch_mmap_rnd() made available via the new
      CONFIG_ARCH_HAS_ELF_RANDOMIZE.  For these architectures,
      arch_randomize_brk() is collapsed as well.
      
      This is an alternative to the solutions in:
      https://lkml.org/lkml/2015/2/23/442
      
      I've been able to test x86 and arm, and the buildbot (so far) seems happy
      with building the rest.
      
      [1] http://cybersecurity.upv.es/attacks/offset2lib/offset2lib.html
      
      This patch (of 10):
      
      In preparation for splitting out ET_DYN ASLR, this moves the ASLR
      calculations for mmap on ARM into a separate routine, similar to x86.
      This also removes the redundant check of personality (PF_RANDOMIZE is
      already set before calling arch_pick_mmap_layout).
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Cc: Hector Marco-Gisbert <hecmargi@upv.es>
      Cc: Russell King <linux@arm.linux.org.uk>
      Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: "David A. Long" <dave.long@linaro.org>
      Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
      Cc: Arun Chandran <achandran@mvista.com>
      Cc: Yann Droneaud <ydroneaud@opteya.com>
      Cc: Min-Hua Chen <orca.chen@gmail.com>
      Cc: Paul Burton <paul.burton@imgtec.com>
      Cc: Alex Smith <alex@alex-smith.me.uk>
      Cc: Markos Chandras <markos.chandras@imgtec.com>
      Cc: Vineeth Vijayan <vvijayan@mvista.com>
      Cc: Jeff Bailey <jeffbailey@google.com>
      Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
      Cc: Ben Hutchings <ben@decadent.org.uk>
      Cc: Behan Webster <behanw@converseincode.com>
      Cc: Ismael Ripoll <iripoll@upv.es>
      Cc: Jan-Simon Mller <dl9pf@gmx.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      a7c8c37b
  2. 03 May, 2016 2 commits
  3. 02 May, 2016 1 commit
  4. 29 Apr, 2016 1 commit
  5. 26 Apr, 2016 24 commits