Commit 05b252cc authored Jun 20, 2022 by Gerd Hoffmann Committed by Linus Torvalds Jun 20, 2022

udmabuf: add back sanity check



Check vm_fault->pgoff before using it.  When we removed the warning, we
also removed the check.

Fixes: 7b26e4e2 ("udmabuf: drop WARN_ON() check.")
Reported-by:  <zdi-disclosures@trendmicro.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent a111daf0

drivers/dma-buf/udmabuf.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -32,8 +32,11 @@ static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf)
		{
		struct vm_area_struct *vma = vmf->vma;
		struct udmabuf *ubuf = vma->vm_private_data;
		pgoff_t pgoff = vmf->pgoff;

		vmf->page = ubuf->pages[vmf->pgoff];
		if (pgoff >= ubuf->pagecount)
		return VM_FAULT_SIGBUS;
		vmf->page = ubuf->pages[pgoff];
		get_page(vmf->page);
		return 0;
		}