From 83af8eda68a3f0c227d0eb05348e58ae27a62e7e 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 (CVE-2008-0007) 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 Signed-off-by: Greg Kroah-Hartman --- drivers/char/drm/drm_vm.c | 2 ++ drivers/char/mspec.c | 3 ++- fs/ncpfs/mmap.c | 3 --- kernel/relay.c | 1 + mm/mmap.c | 2 +- sound/oss/via82cxxx_audio.c | 14 ++++++-------- sound/usb/usx2y/usX2Yhwdep.c | 2 +- sound/usb/usx2y/usx2yhwdeppcm.c | 2 +- 8 files changed, 14 insertions(+), 15 deletions(-) diff --git a/drivers/char/drm/drm_vm.c b/drivers/char/drm/drm_vm.c index b5c5b9fa84c3..e2d7be943cce 100644 --- a/drivers/char/drm/drm_vm.c +++ b/drivers/char/drm/drm_vm.c @@ -520,6 +520,7 @@ static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma) vma->vm_ops = &drm_vm_dma_ops; vma->vm_flags |= VM_RESERVED; /* Don't swap */ + vma->vm_flags |= VM_DONTEXPAND; vma->vm_file = filp; /* Needed for drm_vm_open() */ drm_vm_open_locked(vma); @@ -669,6 +670,7 @@ static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma) return -EINVAL; /* This should never happen. */ } vma->vm_flags |= VM_RESERVED; /* Don't swap */ + vma->vm_flags |= VM_DONTEXPAND; vma->vm_file = filp; /* Needed for drm_vm_open() */ drm_vm_open_locked(vma); diff --git a/drivers/char/mspec.c b/drivers/char/mspec.c index 7ac30612068b..5685b7a77c38 100644 --- a/drivers/char/mspec.c +++ b/drivers/char/mspec.c @@ -265,7 +265,8 @@ mspec_mmap(struct file *file, struct vm_area_struct *vma, int type) vdata->refcnt = ATOMIC_INIT(1); vma->vm_private_data = vdata; - vma->vm_flags |= (VM_IO | VM_LOCKED | VM_RESERVED | VM_PFNMAP); + vma->vm_flags |= (VM_IO | VM_LOCKED | VM_RESERVED | VM_PFNMAP | + VM_DONTEXPAND); if (vdata->type == MSPEC_FETCHOP || vdata->type == MSPEC_UNCACHED) vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); vma->vm_ops = &mspec_vm_ops; diff --git a/fs/ncpfs/mmap.c b/fs/ncpfs/mmap.c index 70a69115500f..f87de9718242 100644 --- a/fs/ncpfs/mmap.c +++ b/fs/ncpfs/mmap.c @@ -47,9 +47,6 @@ static struct page* ncp_file_mmap_nopage(struct vm_area_struct *area, pos = address - area->vm_start + (area->vm_pgoff << PAGE_SHIFT); count = PAGE_SIZE; - if (address + PAGE_SIZE > area->vm_end) { - count = area->vm_end - address; - } /* what we can read in one go */ bufsize = NCP_SERVER(inode)->buffer_size; diff --git a/kernel/relay.c b/kernel/relay.c index 95db8c79fe8f..24db7e81cde4 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -91,6 +91,7 @@ int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma) return -EINVAL; vma->vm_ops = &relay_file_mmap_ops; + vma->vm_flags |= VM_DONTEXPAND; vma->vm_private_data = buf; buf->chan->cb->buf_mapped(buf, filp); diff --git a/mm/mmap.c b/mm/mmap.c index 906ed402f7ca..33fb6718d76d 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2157,7 +2157,7 @@ int install_special_mapping(struct mm_struct *mm, vma->vm_start = addr; vma->vm_end = addr + len; - vma->vm_flags = vm_flags | mm->def_flags; + vma->vm_flags = vm_flags | mm->def_flags | VM_DONTEXPAND; vma->vm_page_prot = protection_map[vma->vm_flags & 7]; vma->vm_ops = &special_mapping_vmops; diff --git a/sound/oss/via82cxxx_audio.c b/sound/oss/via82cxxx_audio.c index 5d3c0372df32..f95aa0946758 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 b76b3dd9df25..e617d7ec6478 100644 --- a/sound/usb/usx2y/usX2Yhwdep.c +++ b/sound/usb/usx2y/usX2Yhwdep.c @@ -88,7 +88,7 @@ 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 a5e7bcd7ca2e..6e70520b75c8 100644 --- a/sound/usb/usx2y/usx2yhwdeppcm.c +++ b/sound/usb/usx2y/usx2yhwdeppcm.c @@ -728,7 +728,7 @@ 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