1. 21 Jul, 2019 38 commits
  2. 10 Jul, 2019 2 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.9.185 · 9c51e110
      Greg Kroah-Hartman authored
      9c51e110
    • Ard Biesheuvel's avatar
      arm64: kaslr: keep modules inside module region when KASAN is enabled · dd862509
      Ard Biesheuvel authored
      commit 6f496a55 upstream.
      
      When KASLR and KASAN are both enabled, we keep the modules where they
      are, and randomize the placement of the kernel so it is within 2 GB
      of the module region. The reason for this is that putting modules in
      the vmalloc region (like we normally do when KASLR is enabled) is not
      possible in this case, given that the entire vmalloc region is already
      backed by KASAN zero shadow pages, and so allocating dedicated KASAN
      shadow space as required by loaded modules is not possible.
      
      The default module allocation window is set to [_etext - 128MB, _etext]
      in kaslr.c, which is appropriate for KASLR kernels booted without a
      seed or with 'nokaslr' on the command line. However, as it turns out,
      it is not quite correct for the KASAN case, since it still intersects
      the vmalloc region at the top, where attempts to allocate shadow pages
      will collide with the KASAN zero shadow pages, causing a WARN() and all
      kinds of other trouble. So cap the top end to MODULES_END explicitly
      when running with KASAN.
      
      Cc: <stable@vger.kernel.org> # 4.9+
      Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Tested-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      [will: backport to 4.9.y]
      Signed-off-by: default avatarWill Deacon <will@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      dd862509