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Commit 3a3fe6e7 authored by Dan Carpenter's avatar Dan Carpenter Committed by Eric Anholt
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drm: shmem: Off by one in drm_gem_shmem_fault() 



The shmem->pages[] array has "num_pages" elements so the > should be >=
to prevent reading beyond the end of the array.  The shmem->pages[]
array is allocated in drm_gem_shmem_prime_import_sg_table().

Fixes: 2194a63a ("drm: Add library for shmem backed GEM objects")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarEric Anholt <eric@anholt.net>
Reviewed-by: default avatarEric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190322064125.GA12551@kadam
parent 3051719a

drivers/gpu/drm/drm_gem_shmem_helper.c

+1 −1
Original line number Diff line number Diff line
@@ -408,7 +408,7 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) 
	loff_t num_pages = obj->size >> PAGE_SHIFT;

	struct page *page;



	if (vmf->pgoff > num_pages || WARN_ON_ONCE(!shmem->pages))

	if (vmf->pgoff >= num_pages || WARN_ON_ONCE(!shmem->pages))

		return VM_FAULT_SIGBUS;



	page = shmem->pages[vmf->pgoff];