| Message ID | 1493823468-19470-1-git-send-email-catalin.marinas@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, May 03, 2017 at 03:57:48PM +0100, Catalin Marinas wrote: > The dma_common_pages_remap() function allocates a vm_struct object and > initialises the pages pointer to value passed as argument. However, when > this function is called dma_common_contiguous_remap(), the pages array > is only temporarily allocated, being freed shortly after > dma_common_contiguous_remap() returns. Architecture code checking the > validity of an area->pages pointer would incorrectly dereference already > freed pointers. This has been exposed by the arm64 commit 44176bb38fa4 > ("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU"). > > Fixes: 513510ddba96 ("common: dma-mapping: introduce common remapping functions") > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Reported-by: Andrzej Hajda <a.hajda@samsung.com> > Acked-by: Laura Abbott <labbott@redhat.com> > Reviewed-by: Robin Murphy <robin.murphy@arm.com> > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> > --- > > Greg, > > Please merge this patch via your tree (and therefore I haven't added > your ack). Thanks. Ok, will queue it up after 4.12-rc1 is out. thanks, greg k-h
On Wed, May 03, 2017 at 03:57:48PM +0100, Catalin Marinas wrote: > The dma_common_pages_remap() function allocates a vm_struct object and > initialises the pages pointer to value passed as argument. However, when > this function is called dma_common_contiguous_remap(), the pages array > is only temporarily allocated, being freed shortly after > dma_common_contiguous_remap() returns. Architecture code checking the > validity of an area->pages pointer would incorrectly dereference already > freed pointers. This has been exposed by the arm64 commit 44176bb38fa4 > ("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU"). > > Fixes: 513510ddba96 ("common: dma-mapping: introduce common remapping functions") > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Reported-by: Andrzej Hajda <a.hajda@samsung.com> > Acked-by: Laura Abbott <labbott@redhat.com> > Reviewed-by: Robin Murphy <robin.murphy@arm.com> > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> > --- > > Greg, > > Please merge this patch via your tree (and therefore I haven't added > your ack). Thanks. I just tried to, but it doesn't apply to 4.12-rc2 :( Can you refresh this and resend? thanks, greg k-h
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c index efd71cf4fdea..ac224de462f6 100644 --- a/drivers/base/dma-mapping.c +++ b/drivers/base/dma-mapping.c @@ -273,6 +273,24 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, EXPORT_SYMBOL(dma_common_mmap); #ifdef CONFIG_MMU +static struct vm_struct *__dma_common_pages_remap(struct page **pages, + size_t size, unsigned long vm_flags, pgprot_t prot, + const void *caller) +{ + struct vm_struct *area; + + area = get_vm_area_caller(size, vm_flags, caller); + if (!area) + return NULL; + + if (map_vm_area(area, prot, pages)) { + vunmap(area->addr); + return NULL; + } + + return area; +} + /* * remaps an array of PAGE_SIZE pages into another vm_area * Cannot be used in non-sleeping contexts @@ -283,17 +301,12 @@ void *dma_common_pages_remap(struct page **pages, size_t size, { struct vm_struct *area; - area = get_vm_area_caller(size, vm_flags, caller); + area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller); if (!area) return NULL; area->pages = pages; - if (map_vm_area(area, prot, pages)) { - vunmap(area->addr); - return NULL; - } - return area->addr; } @@ -308,7 +321,7 @@ void *dma_common_contiguous_remap(struct page *page, size_t size, { int i; struct page **pages; - void *ptr; + struct vm_struct *area; unsigned long pfn; pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL); @@ -318,11 +331,13 @@ void *dma_common_contiguous_remap(struct page *page, size_t size, for (i = 0, pfn = page_to_pfn(page); i < (size >> PAGE_SHIFT); i++) pages[i] = pfn_to_page(pfn + i); - ptr = dma_common_pages_remap(pages, size, vm_flags, prot, caller); + area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller); kfree(pages); - return ptr; + if (!area) + return NULL; + return area->addr; } /*
The dma_common_pages_remap() function allocates a vm_struct object and initialises the pages pointer to value passed as argument. However, when this function is called dma_common_contiguous_remap(), the pages array is only temporarily allocated, being freed shortly after dma_common_contiguous_remap() returns. Architecture code checking the validity of an area->pages pointer would incorrectly dereference already freed pointers. This has been exposed by the arm64 commit 44176bb38fa4 ("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU"). Fixes: 513510ddba96 ("common: dma-mapping: introduce common remapping functions") Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reported-by: Andrzej Hajda <a.hajda@samsung.com> Acked-by: Laura Abbott <labbott@redhat.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> --- Greg, Please merge this patch via your tree (and therefore I haven't added your ack). Thanks. Changes since v1: - Kept the original comment near the dma_common_pages_remap() function - Added acks/reviews drivers/base/dma-mapping.c | 33 ++++++++++++++++++++++++--------- 1 file changed, 24 insertions(+), 9 deletions(-)