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authorNick Piggin <npiggin@suse.de>2008-02-01 21:08:53 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2008-02-04 10:55:38 -0500
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 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,
2104{ 2104{
2105 struct via_info *card = vma->vm_private_data; 2105 struct via_info *card = vma->vm_private_data;
2106 struct via_channel *chan = &card->ch_out; 2106 struct via_channel *chan = &card->ch_out;
2107 unsigned long max_bufs;
2107 struct page *dmapage; 2108 struct page *dmapage;
2108 unsigned long pgoff; 2109 unsigned long pgoff;
2109 int rd, wr; 2110 int rd, wr;
@@ -2127,14 +2128,11 @@ static struct page * via_mm_nopage (struct vm_area_struct * vma,
2127 rd = card->ch_in.is_mapped; 2128 rd = card->ch_in.is_mapped;
2128 wr = card->ch_out.is_mapped; 2129 wr = card->ch_out.is_mapped;
2129 2130
2130#ifndef VIA_NDEBUG 2131 max_bufs = chan->frag_number;
2131 { 2132 if (rd && wr)
2132 unsigned long max_bufs = chan->frag_number; 2133 max_bufs *= 2;
2133 if (rd && wr) max_bufs *= 2; 2134 if (pgoff >= max_bufs)
2134 /* via_dsp_mmap() should ensure this */ 2135 return NOPAGE_SIGBUS;
2135 assert (pgoff < max_bufs);
2136 }
2137#endif
2138 2136
2139 /* if full-duplex (read+write) and we have two sets of bufs, 2137 /* if full-duplex (read+write) and we have two sets of bufs,
2140 * then the playback buffers come first, sez soundcard.c */ 2138 * then the playback buffers come first, sez soundcard.c */