Commit 8c52ac9e authored by Andi Shyti's avatar Andi Shyti Committed by Cui GaoSheng
Browse files

drm/i915/gem: Fix Virtual Memory mapping boundaries calculation 

stable inclusion
from stable-v5.10.224
commit 50111a8098fb9ade621eeff82228a997d42732ab
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAMM9L
CVE: CVE-2024-42259

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=50111a8098fb9ade621eeff82228a997d42732ab



--------------------------------

commit 8bdd9ef7e9b1b2a73e394712b72b22055e0e26c3 upstream.

Calculating the size of the mapped area as the lesser value
between the requested size and the actual size does not consider
the partial mapping offset. This can cause page fault access.

Fix the calculation of the starting and ending addresses, the
total size is now deduced from the difference between the end and
start addresses.

Additionally, the calculations have been rewritten in a clearer
and more understandable form.

Fixes: c58305af ("drm/i915: Use remap_io_mapping() to prefault all PTE in a single pass")
Reported-by: default avatarJann Horn <jannh@google.com>
Co-developed-by: default avatarChris Wilson <chris.p.wilson@linux.intel.com>
Signed-off-by: default avatarChris Wilson <chris.p.wilson@linux.intel.com>
Signed-off-by: default avatarAndi Shyti <andi.shyti@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: <stable@vger.kernel.org> # v4.9+
Reviewed-by: default avatarJann Horn <jannh@google.com>
Reviewed-by: default avatarJonathan Cavitt <Jonathan.cavitt@intel.com>
[Joonas: Add Requires: tag]
Requires: 60a2066c5005 ("drm/i915/gem: Adjust vma offset for framebuffer mmap offset")
Signed-off-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240802083850.103694-3-andi.shyti@linux.intel.com


(cherry picked from commit 97b6784753da06d9d40232328efc5c5367e53417)
Signed-off-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarCui GaoSheng <cuigaosheng1@huawei.com>
parent 683fc19e

drivers/gpu/drm/i915/gem/i915_gem_mman.c

+47 −6
Original line number Diff line number Diff line
@@ -272,6 +272,41 @@ static vm_fault_t vm_fault_cpu(struct vm_fault *vmf) 
	return i915_error_to_vmf_fault(err);

}



static void set_address_limits(struct vm_area_struct *area,

			       struct i915_vma *vma,

			       unsigned long obj_offset,

			       unsigned long *start_vaddr,

			       unsigned long *end_vaddr)

{

	unsigned long vm_start, vm_end, vma_size; /* user's memory parameters */

	long start, end; /* memory boundaries */



	/*

	 * Let's move into the ">> PAGE_SHIFT"

	 * domain to be sure not to lose bits

	 */

	vm_start = area->vm_start >> PAGE_SHIFT;

	vm_end = area->vm_end >> PAGE_SHIFT;

	vma_size = vma->size >> PAGE_SHIFT;



	/*

	 * Calculate the memory boundaries by considering the offset

	 * provided by the user during memory mapping and the offset

	 * provided for the partial mapping.

	 */

	start = vm_start;

	start -= obj_offset;

	start += vma->ggtt_view.partial.offset;

	end = start + vma_size;



	start = max_t(long, start, vm_start);

	end = min_t(long, end, vm_end);



	/* Let's move back into the "<< PAGE_SHIFT" domain */

	*start_vaddr = (unsigned long)start << PAGE_SHIFT;

	*end_vaddr = (unsigned long)end << PAGE_SHIFT;

}



static vm_fault_t vm_fault_gtt(struct vm_fault *vmf)

{

#define MIN_CHUNK_PAGES (SZ_1M >> PAGE_SHIFT)
@@ -284,14 +319,18 @@ static vm_fault_t vm_fault_gtt(struct vm_fault *vmf) 
	struct i915_ggtt *ggtt = &i915->ggtt;

	bool write = area->vm_flags & VM_WRITE;

	struct i915_gem_ww_ctx ww;

	unsigned long obj_offset;

	unsigned long start, end; /* memory boundaries */

	intel_wakeref_t wakeref;

	struct i915_vma *vma;

	pgoff_t page_offset;

	unsigned long pfn;

	int srcu;

	int ret;



	/* We don't use vmf->pgoff since that has the fake offset */

	obj_offset = area->vm_pgoff - drm_vma_node_start(&mmo->vma_node);

	page_offset = (vmf->address - area->vm_start) >> PAGE_SHIFT;

	page_offset += obj_offset;



	trace_i915_gem_object_fault(obj, page_offset, true, write);
@@ -362,12 +401,14 @@ static vm_fault_t vm_fault_gtt(struct vm_fault *vmf) 
	if (ret)

		goto err_unpin;



	set_address_limits(area, vma, obj_offset, &start, &end);



	pfn = (ggtt->gmadr.start + i915_ggtt_offset(vma)) >> PAGE_SHIFT;

	pfn += (start - area->vm_start) >> PAGE_SHIFT;

	pfn += obj_offset - vma->ggtt_view.partial.offset;



	/* Finally, remap it using the new GTT offset */

	ret = remap_io_mapping(area,

			       area->vm_start + (vma->ggtt_view.partial.offset << PAGE_SHIFT),

			       (ggtt->gmadr.start + vma->node.start) >> PAGE_SHIFT,

			       min_t(u64, vma->size, area->vm_end - area->vm_start),

			       &ggtt->iomap);

	ret = remap_io_mapping(area, start, pfn, end - start, &ggtt->iomap);

	if (ret)

		goto err_fence;