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authorNick Piggin <npiggin@suse.de>2008-02-02 03:08:53 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2008-02-04 07:55:38 -0800
commit2f98735c9c24ea1f0d40a364d4e63611b689b795 (patch)
treea42b3802449af474d36cda3b6f9fb190a717defb /sound/oss
parentfe2528b96b02173395f5a75e37714c07f3e25e73 (diff)
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 <npiggin@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'sound/oss')
-rw-r--r--sound/oss/via82cxxx_audio.c14
1 files changed, 6 insertions, 8 deletions
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 */