| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.0 085/115] drm/ttm: fix out-of-bounds read in ttm_put_pages() v2 | Date | Wed, 24 Apr 2019 19:10:21 +0200 |
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From: Christian König <christian.koenig@amd.com>
commit a66477b0efe511d98dde3e4aaeb189790e6f0a39 upstream.
When ttm_put_pages() tries to figure out whether it's dealing with transparent hugepages, it just reads past the bounds of the pages array without a check.
v2: simplify the test if enough pages are left in the array (Christian).
Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Christian König <christian.koenig@amd.com> Fixes: 5c42c64f7d54 ("drm/ttm: fix the fix for huge compound pages") Cc: stable@vger.kernel.org Reviewed-by: Michel Dänzer <michel.daenzer@amd.com> Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com> Reviewed-by: Huang Rui <ray.huang@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/gpu/drm/ttm/ttm_page_alloc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/ttm/ttm_page_alloc.c +++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c @@ -730,7 +730,8 @@ static void ttm_put_pages(struct page ** } #ifdef CONFIG_TRANSPARENT_HUGEPAGE - if (!(flags & TTM_PAGE_FLAG_DMA32)) { + if (!(flags & TTM_PAGE_FLAG_DMA32) && + (npages - i) >= HPAGE_PMD_NR) { for (j = 0; j < HPAGE_PMD_NR; ++j) if (p++ != pages[i + j]) break; @@ -759,7 +760,7 @@ static void ttm_put_pages(struct page ** unsigned max_size, n2free; spin_lock_irqsave(&huge->lock, irq_flags); - while (i < npages) { + while ((npages - i) >= HPAGE_PMD_NR) { struct page *p = pages[i]; unsigned j;
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