From 2f98735c9c24ea1f0d40a364d4e63611b689b795 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Sat, 2 Feb 2008 03:08:53 +0100 Subject: vm audit: add VM_DONTEXPAND to mmap for drivers that need it Drivers that register a ->fault handler, but do not range-check the offset argument, must set VM_DONTEXPAND in the vm_flags in order to prevent an expanding mremap from overflowing the resource. I've audited the tree and attempted to fix these problems (usually by adding VM_DONTEXPAND where it is not obvious). Signed-off-by: Nick Piggin Signed-off-by: Linus Torvalds --- sound/oss/via82cxxx_audio.c | 14 ++++++-------- sound/usb/usx2y/usX2Yhwdep.c | 2 +- sound/usb/usx2y/usx2yhwdeppcm.c | 2 +- 3 files changed, 8 insertions(+), 10 deletions(-) (limited to 'sound') diff --git a/sound/oss/via82cxxx_audio.c b/sound/oss/via82cxxx_audio.c index 5d3c0372df3..f95aa094675 100644 --- a/sound/oss/via82cxxx_audio.c +++ b/sound/oss/via82cxxx_audio.c @@ -2104,6 +2104,7 @@ static struct page * via_mm_nopage (struct vm_area_struct * vma, { struct via_info *card = vma->vm_private_data; struct via_channel *chan = &card->ch_out; + unsigned long max_bufs; struct page *dmapage; unsigned long pgoff; int rd, wr; @@ -2127,14 +2128,11 @@ static struct page * via_mm_nopage (struct vm_area_struct * vma, rd = card->ch_in.is_mapped; wr = card->ch_out.is_mapped; -#ifndef VIA_NDEBUG - { - unsigned long max_bufs = chan->frag_number; - if (rd && wr) max_bufs *= 2; - /* via_dsp_mmap() should ensure this */ - assert (pgoff < max_bufs); - } -#endif + max_bufs = chan->frag_number; + if (rd && wr) + max_bufs *= 2; + if (pgoff >= max_bufs) + return NOPAGE_SIGBUS; /* if full-duplex (read+write) and we have two sets of bufs, * then the playback buffers come first, sez soundcard.c */ diff --git a/sound/usb/usx2y/usX2Yhwdep.c b/sound/usb/usx2y/usX2Yhwdep.c index 6495534e5bf..1558a5c4094 100644 --- a/sound/usb/usx2y/usX2Yhwdep.c +++ b/sound/usb/usx2y/usX2Yhwdep.c @@ -84,7 +84,7 @@ static int snd_us428ctls_mmap(struct snd_hwdep * hw, struct file *filp, struct v us428->us428ctls_sharedmem->CtlSnapShotLast = -2; } area->vm_ops = &us428ctls_vm_ops; - area->vm_flags |= VM_RESERVED; + area->vm_flags |= VM_RESERVED | VM_DONTEXPAND; area->vm_private_data = hw->private_data; return 0; } diff --git a/sound/usb/usx2y/usx2yhwdeppcm.c b/sound/usb/usx2y/usx2yhwdeppcm.c index 800b5cecfc8..117946f2deb 100644 --- a/sound/usb/usx2y/usx2yhwdeppcm.c +++ b/sound/usb/usx2y/usx2yhwdeppcm.c @@ -722,7 +722,7 @@ static int snd_usX2Y_hwdep_pcm_mmap(struct snd_hwdep * hw, struct file *filp, st return -ENODEV; } area->vm_ops = &snd_usX2Y_hwdep_pcm_vm_ops; - area->vm_flags |= VM_RESERVED; + area->vm_flags |= VM_RESERVED | VM_DONTEXPAND; area->vm_private_data = hw->private_data; return 0; } -- cgit v1.2.3