[ 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>
{
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;
}