lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Thu, 16 Apr 2015 16:41:52 +0200
From:	Ørjan Eide <orjan.eide@....com>
To:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	dri-devel@...ts.freedesktop.org, linux-rockchip@...ts.infradead.org
Cc:	djkurtz@...omium.org
Subject: [PATCH 2/2] ARM: DMA: Use vm_pgoff for IOMMU mmap

arm_iommu_mmap_attrs() ignores the page offset in vma->vm_pgoff that was
specified in the mmap call. Any user of dma_mmap_* will get an
unexpected result when the device uses the IOMMU DMA ops.

Some DRM driver that use dma_mmap_* seems to depend on it ignoring
vma->vm_pgoff.  Both the Samsung Exynos DRM driver before v3.18, and the
current Rockchip DRM driver, use the page offset to pass GEM cookies
that are used to look up the GEM buffers and then call dma_mmap_attrs()
with the cookie value still in vma->vm_pgoff.

rockchip_gem_mmap_buf() in drivers/gpu/drm/rockchip/rockchip_drm_gem.c
still does this. It should be fixed before fixing
arm_iommu_mmap_attrs().

Signed-off-by: Ørjan Eide <orjan.eide@....com>
---
 arch/arm/mm/dma-mapping.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index c274476..07d571b 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1364,6 +1364,9 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
 {
 	unsigned long uaddr = vma->vm_start;
 	unsigned long usize = vma->vm_end - vma->vm_start;
+	unsigned long nr_vma_pages = usize >> PAGE_SHIFT;
+	unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	unsigned long off = vma->vm_pgoff;
 	struct page **pages = __iommu_get_pages(cpu_addr, attrs);
 
 	vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
@@ -1371,6 +1374,11 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
 	if (!pages)
 		return -ENXIO;
 
+	if (off >= nr_pages || nr_vma_pages > (nr_pages - off))
+		return -ENXIO;
+
+	pages += off;
+
 	do {
 		int ret = vm_insert_page(vma, uaddr, *pages++);
 		if (ret) {
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists