From: Gerd Hoffmann kraxel@redhat.com
[ Upstream commit 05b252cccb2e5c3f56119d25de684b4f810ba40a ]
Check vm_fault->pgoff before using it. When we removed the warning, we also removed the check.
Fixes: 7b26e4e2119d ("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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma-buf/udmabuf.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index cfbf10128aae..2e3b76519b49 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -26,8 +26,11 @@ 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; }