1. 05 Feb, 2020 1 commit
    • Takashi Iwai's avatar
      ALSA: pcm: Add missing copy ops check before clearing buffer · ea4df337
      Takashi Iwai authored
      [ this is a fix specific to 4.4.y and 4.9.y stable trees;
        4.14.y and older already contain the right fix ]
      
      The stable 4.4.y and 4.9.y backports of the upstream commit
      add9d56d ("ALSA: pcm: Avoid possible info leaks from PCM stream
      buffers") dropped the check of substream->ops->copy_user as copy_user
      is a new member that isn't present in the older kernels.
      Although upstream drivers should work without this NULL check, it may
      cause a regression with a downstream driver that sets some
      inaccessible address to runtime->dma_area, leading to a crash at
      worst.
      
      Since such drivers must have ops->copy member on older kernels instead
      of ops->copy_user, this patch adds the missing check of ops->copy for
      fixing the regression.
      Reported-and-tested-by: default avatarAndreas Schneider <asn@cryptomilk.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ea4df337
  2. 29 Jan, 2020 39 commits